ABSTRACT:Kimura disease typically presents with painless head and neck swelling in young adults of Asian descent, accompanied by peripheral eosinophilia and elevated serum IgE. We report a case of Kimura disease in a woman in her early 30s presenting with a slowly enlarging epitrochlear mass, diffuse encasement of the median and medial brachial cutaneous nerves, and a concurrent prurigo nodularis-like papular rash affecting all 4 extremities. The diagnosis required over 1 year of investigation and 5 tissue specimens, including 2 nondiagnostic core-needle biopsies, before near total excision was performed. The excision revealed characteristic histopathologic features, including hyperplastic reactive secondary lymphoid follicles with preserved architecture, a marked eosinophilic infiltrate with eosinophilic microabscesses, postcapillary venule proliferation, and patternless stromal fibrosis. Immunohistochemistry demonstrated a raised IgG4:IgG plasma cell ratio of approximately 1:1, with 150-200 IgG4-positive plasma cells per high-power field, raising the differential of IgG4-related disease; however, the absence of storiform fibrosis and obliterative phlebitis, combined with the clinical and serologic profile, favored Kimura disease. This case is notable for its rare epitrochlear location, extensive neural involvement, concurrent diffuse cutaneous eruption, and histopathologic overlap with IgG4-related disease, highlighting the diagnostic challenges posed by atypical presentations of Kimura disease.

BACKGROUND:Ecchordosis physaliphora (EP), a benign extraosseous notochordal remnant, has been found in 0.4%-2% of autopsies. It most commonly occurs on the dorsal surface of the clivus and is rarely symptomatic. Extraosseous notochordal lesions involving the spine are also rare, with the majority being diagnosed as chordoma. OBSERVATIONS:The authors report a case of an extradural extraosseous notochordal lesion within the left L5-S1 nerve root foramen resulting in left lumbar L5 radiculopathy in a 46-year-old woman. Microdecompression at the left lumbar L5-S1 level permitted successful removal of the lesion and complete resolution of radiculopathy. The combined histopathological and retrospective imaging findings were felt to be consistent with EP. Thirty-nine-month follow-up imaging revealed no recurrence of the lesion, and the patient remains asymptomatic at last follow-up. LESSONS:Challenges in diagnosing EP, particularly distinguishing it from extraosseous chordoma, and the implications of diagnostic terminology on the management of these lesions are discussed. https://thejns.org/doi/10.3171/CASE26203.

RATIONALE AND OBJECTIVES:This study aims to evaluate planar 99 mTc-MDP bone scan in vertebral chordoma staging and compare scintigraphy with computed tomography (CT) morphology. MATERIALS AND METHODS:An IRB-approved retrospective review was performed for patients with biopsy-proven chordoma who underwent planar 99 mTc-MDP bone scan and CT within three months of diagnosis. Lesion location, degree of primary uptake, foci of additional uptake, size, and CT morphology were recorded. RESULTS:Fifty-six patients (31 M, 25 F, mean age 56.8 ± 16.3 years) with 43 sacrococcygeal, 8 lumbar, and 5 cervical spine lesions had mean tumor dimensions of 7.1 ± 5.2 cm. On CT, lesions demonstrated characteristics including occult, purely lytic, lytic with surrounding reactive/sclerotic bone, and mixed lytic/sclerotic. On bone scan, lesions demonstrated uptake, ranging from photopenic to marked uptake. There was no association between the pattern of bone involvement and degree (p = 0.45) or presence (p = 0.29) of uptake, or lesion size and degree (p = 0.381) or presence (p = 0.092) of uptake. 17 patients had focal uptake on bone scan suspicious for osseous metastasis, but further workup confirmed true metastasis in only one patient. Alternative etiologies for bone scan uptake were most commonly due to primary benign bone lesions, degenerative changes, and fracture. CONCLUSION:A considerable proportion of vertebral chordomas are occult on planar 99 mTc-MDP bone scan, irrespective of their pattern of bone involvement on CT. Osseous metastases from chordoma are uncommon at initial staging, and bone scan is prone to false positive findings. These results question the routine use of bone scan in staging vertebral chordoma.

Bone and soft tissue sarcomas harboring EWSR1::NFATC2 and FUS::NFATC2 fusions (NFATC2-rearranged sarcomas) is a recently defined entity with a morphologic spectrum and clinical behavior that are not fully elucidated. We studied 32 such sarcomas that occurred in 21 male and 11 female patients. The EWSR1::NFATC2 fusion was found in tumors of 25 patients (17 M, 8 F; median age: 40, range: 14-78), 16 of which arose in soft tissue, while 8 originated in bone. Morphologically, they showed relatively consistent morphologic features yet variable degrees of cytologic atypia, mitotic rates and necrosis. Follow-up (19 patients; median: 22 months, range: 1-70) demonstrated local recurrence in 3 patients, while distant metastases occurred in 6 patients. Two patients died of disease (DOD), 4 were alive with disease (AWD) and 13 were without evidence of disease (AWOD). In contrast, the FUS::NFATC2 fusion was exclusively seen in osseous tumors, which occurred in 7 patients (4 M, 3 F; median age: 32, range: 4-62). Further, FUS::NFATC2 tumors showed significant morphologic heterogeneity. Follow-up (6 patients; median: 18 months, range: 13-60) demonstrated local recurrence in 2 patients, and lung metastases in 2 patients. At last follow-up, 3 patients were AWD, while 3 patients were AWOD. Using a two-tiered grading scheme based on cytologic atypia, mitotic rate, and necrosis, patients with low-grade tumors experienced significantly fewer adverse events than those classified as high-grade (p=0.026); however, estimated metastasis-free survival was not statistically significant due to our limited sample size. Overall, our study expands on the morphologic spectrum of NFATC2-rearranged sarcomas and highlights the clinicopathologic, molecular, and genetic differences between the EWSR1- and FUS-rearranged tumors. Although additional long-term follow-up data is required, our study further suggests that a subset of these sarcomas have a protracted clinical course while high-grade morphologic features such as atypia, mitotic activity and necrosis may correlate with worse behavior.

RATIONALE AND OBJECTIVES:To examine MRI characteristics of malignant tenosynovial giant cell tumors (TSGCTs) and elucidate features to differentiate benign and malignant TSGCTs. MATERIALS AND METHODS:With IRB approval, the medical record was retrospectively reviewed from 2004-2024 for cases of pathologically-proven benign and malignant TSGCTs evaluated by MRI. RESULTS:12 malignant TSGCTs (5F/7M, mean age 48.7 +/- 17.6 years) and 23 benign TSGCTs (13F/10M, mean age 43.7 +/- 18.7 years) were identified. There was no significant difference in age (p=0.45), gender (p=0.63), MRI signal characteristics (T1 signal p=0.57, T2 signal p=0.46, T2 signal heterogeneity p>0.99, presence of low T2 signal p>0.99), type of enhancement (presence of enhancement p=0.21, degree of enhancement p=0.12, heterogenous vs. homogenous enhancement p=0.21, presence of non-enhancing areas p=0.11), blooming artifact (p=0.065), or presence of perilesional edema (p=0.16) between benign and malignant TSGCTs. Four MRI features were more commonly associated with malignant TSGCTs: extra-articular location (p=0.009), irregular margins (p=0.0014), perilesional vessels (p=0.0014), and larger average maximal dimension (8.6 +/- 8.4 cm malignant vs. 2.8 +/- 2.2 cm benign, p=0.036). CONCLUSION:Although there are overlapping MRI characteristics between benign and malignant TSGCTs, malignant TSGCTs are more likely to exhibit larger size, extra-articular location, irregular margins and prominent perilesional vessels compared to their benign counterparts. Some malignant TSGCTs may not be associated with a synovial-lined structure on imaging.

Poorly differentiated chordoma (PDC) is an aggressive subtype of chordoma characterized by SMARCB1 (INI1) loss and a dismal prognosis. It typically involves the axial skeleton, most commonly the skull base and the cervical spine. To our knowledge, only 5 cases of extraaxial PDC (EAPDC) have been reported, and the natural history of these tumors is not fully understood. We studied 6 cases of EAPDC, with the goal of better understanding these exceptionally rare tumors. The tumors occurred in 4 women and 2 men, ranging from 37 to 68 years of age (median, 57.5 years) and involved or originated in the left knee joint (3 cases), right knee joint (2 cases), and right wrist (1 case). Grossly, all were solid and lobulated, with areas of necrosis. Histologically, the tumors were identical to axial PDC, with sheets and lobules of overtly malignant-appearing epithelioid-to-rhabdoid cells with prominent nucleoli. Mitotic activity and necrosis were present. By immunohistochemistry, all cases expressed keratins and brachyury and were SMARCB1 deficient. Molecular genetic analysis identified SMARCB1 loss-of-function alterations in 4 of the tested cases, including mutations (2 cases) and copy number loss (2 cases). DNA methylation profiling of 4 cases of EAPDC showed clustering with axial PDC. Clinical follow-up (6 patients; median, 11.5 months; range, 1-26 months) showed 4 patients to have received transfemoral amputation and 1 extraarticular resection. None received neoadjuvant radiotherapy; 1 received neoadjuvant chemotherapy and 1 adjuvant chemotherapy/ immunotherapy. Local recurrences were seen in 2 patients at 7 and 8 months; 3 patients developed metastases 7-11 months after surgery. Two patients were alive with metastatic disease (at 7 and 13 months), 1 died of disease (20 months), and 3 were disease free (1-26 months). We conclude that EAPDC are aggressive malignancies with an unusual predilection for the knee joint and unknown pathogenesis. (c) 2024 United States & Canadian Academy of Pathology. Published by Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

Hidradenocarcinoma is a rare and aggressive malignant cutaneous adnexal tumor that originates from the intradermal ducts of eccrine sweat glands. Herein, we report a case of hidradenocarcinoma that had transformed from a previously excised benign hidradenoma. [18F] FDG PET/CT revealed an FDG-avid mass in the left calf, and extensive metastatic disease, including soft tissue, pulmonary, osseous, and extensive nodal metastases. This case underscores the potential for malignant transformation of hidradenoma and highlights the utility of [18F] FDG PET/CT in staging hidradenocarcinoma.

BACKGROUND:We retrospectively assessed volumetric response of myxoid liposarcoma (MLPS) with preoperative radiotherapy (RT) and sought to identify disease and treatment characteristics associated with response. PATIENTS AND METHODS:We identified all patients with a histologic diagnosis of MLPS who received preoperative RT from 2013 to 2021 at our institution. We used cone beam computed tomography (CBCT) to assess changes in tumor volume and greatest dimension during treatment. Tumors were contoured on CBCT images prior to treatment and at the end of each week of RT. Percentage change in tumor volume and greatest dimension were calculated based on pre-treatment and final week contours. Patients with tumors incompletely visualized on CBCT were excluded from volume analysis but included on greatest dimension analysis. Magnetic resonance imaging (MRI) was used to evaluate pre- and post-RT radiographic features. Surgical pathology was reviewed to record pathologic characteristics. RESULTS:Twenty patients met inclusion criteria. Most tumors (18/20) were low grade. The most frequent dose/fractionation scheme was 50 Gy in 25 fractions (16/20), with 3 patients receiving 36 Gy in 18 fractions. Median pre-RT volume and greatest dimension were 120 cc (interquartile range [IQR]: 56-399) and 11.2 cm (IQR: 8.4-14.1), respectively. Median percentage change in volume and greatest dimension were -37% (IQR: -57 to -29) and -10% (IQR: -20 to -7). All evaluable tumors decreased in volume during RT. Between pre- and post-RT MRI, most patients had a decrease in intratumoral (16/20) and peritumoral edema (11/20). Sixteen patients exhibited extensive pathologic response. There were no significant associations between radiographic and pathologic features and volumetric change. Local failure at 3 years was 9% (95% confidence interval: 1-59). CONCLUSIONS:We report significant decreases in MLPS tumor size during preoperative RT. There may be a role for adaptive RT planning to reduce target volumes and minimize RT-associated morbidity.

BACKGROUND:Skip lesions in bone sarcoma are a poorly described entity. Reports on skip lesions in osteosarcoma and Ewing sarcoma suggest that whole bone MRI should be obtained to evaluate for additional tumor foci given the association with worse outcomes. However, there is limited evidence to support whole bone imaging in chondrosarcoma. METHODS:Between 1995 and 2022, 129 patients with long bone chondrosarcoma were evaluated at our institution. Lesions were located most commonly in the femur in 64 patients and the humerus in 54 patients. All imaging studies and pathology reports were reviewed to determine the presence of skip lesions, defined as an area of histology-confirmed chondrosarcoma that was separated from the primary lesion by normal bone on pathology. RESULTS:Whole bone imaging was obtained during initial staging in 107 patients with two-thirds of patients receiving MRI, CT, or bone scan. Five patients (3.9%) were found to have skip lesions in the same bone as the primary tumor. There were no transarticular skip lesions. Skip lesions were detected in three patients with low grade chondrosarcoma (4.6%) and two patients with high grade chondrosarcoma (3.2%). All lesions were within 2 cm of the primary tumor. All were visible on MRI and CT of the primary site and one was visible on plain radiographs. The presence of skip lesions did not alter the type of surgical treatment in any patients. CONCLUSION:Skip lesions in long bone chondrosarcoma are rare. All skip lesions in this study were in close proximity to the primary tumor and the same grade as the main lesion. Our results suggest that advanced imaging of the whole bone may be of low utility for evaluating the presence of skip lesions. The clinical significance of skip lesions in chondrosarcoma remains unclear, however, their presence did not impact the treatment plan in this series.

Background Discrepancies in medical data sets can perpetuate bias, especially when training deep learning models, potentially leading to biased outcomes in clinical applications. Understanding these biases is crucial for the development of equitable healthcare technologies. This study employs generative deep learning technology to explore and understand radiographic differences based on race among patients undergoing total hip arthroplasty. Methods Utilizing a large institutional registry, we retrospectively analyzed pelvic radiographs from total hip arthroplasty patients, characterized by demographics and image features. Denoising diffusion probabilistic models generated radiographs conditioned on demographic and imaging characteristics. Fréchet Inception Distance assessed the generated image quality, showing the diversity and realism of the generated images. Sixty transition videos were generated that showed transforming White pelvises to their closest African American counterparts and vice versa while controlling for patients’ sex, age, and body mass index. Two expert surgeons and 2 radiologists carefully studied these videos to understand the systematic differences that are present in the 2 races’ radiographs. Results Our data set included 480,407 pelvic radiographs, with a predominance of White patients over African Americans. The generative denoising diffusion probabilistic model created high-quality images and reached an Fréchet Inception Distance of 6.8. Experts identified 6 characteristics differentiating races, including interacetabular distance, osteoarthritis degree, obturator foramina shape, femoral neck-shaft angle, pelvic ring shape, and femoral cortical thickness. Conclusions This study demonstrates the potential of generative models for understanding disparities in medical imaging data sets. By visualizing race-based differences, this method aids in identifying bias in downstream tasks, fostering the development of fairer healthcare practices.

Retrospectively evaluate multimodality imaging features of perinephric myxoid pseudotumor of fat (PMPTF). Institutional cases of PMPTF with CT, MRI and/or ultrasound evaluation from 1/1/2020 to 9/1/2023 were retrospectively reviewed. Patient demographics and clinical history were reviewed, and imaging features recorded. 14 patients with pathologically-proven PMPTF were identified (11 M, 3 F; mean age 66.7 ± 17.0 years; range 40–87 years). Three patients (18

Tumors resembling tenosynovial giant cell tumor (TGCT) but additionally forming chondroid matrix are rare and most often involve the temporomandibular joint (TMJ). We studied 21 tumors consisting of synoviocytes (large, eosinophilic mononuclear cells containing hemosiderin) and chondroid matrix to better understand these unusual neoplasms. The tumors occurred in 10 males and 11 females, in the age group of 31 to 80 years (median, 50 years) and involved the TMJ region (16), extremities (4), and spine (1). As in conventional TGCT, all were composed of synoviocytes, small histiocytes, foamy macrophages, siderophages, and osteoclast-like giant cells in variably hyalinized background. Expansile nodules of large, moderately atypical synoviocytes were present, in addition to "chondroblastoma-like," "chondroma-like," or "phosphaturic mesenchymal tumor-like" calcified matrix. The synoviocytes expressed clusterin (17/19) and less often desmin (3/15). The tumors were frequently CSF1 positive by chromogenic in situ hybridization (8/13) but at best weakly positive for CSF1 by immunohistochemistry (0/3). Background small histiocytes were CD163 positive (12/12). All were FGF23 negative (0/10). Cells within lacunae showed a synoviocytic phenotype (clusterin positive; S100 protein and ERG negative). RNA-Seq was successful in 13 cases; fusions were present in 7 tumors, including FN1::TEK (5 cases); FN1::PRG4 (2 cases); and MALAT1::FN1, PDGFRA::USP35, and TIMP3::ZCCHC7 (1 case each). Three tumors contained more than 1 fusion (FN1::PRG4 with TIMP3::ZCCHC7, FN1::TEK with FN1::PRG4, and FN1::TEK with MALAT1::FN1). Clinical follow-up (17 patients; median follow-up duration 38 months; range 4-173 months) showed 13 (76%) to be alive without evidence of disease and 4 (24%) to be alive with persistent/recurrent local disease. No metastases or deaths from disease were observed. We conclude that these unusual tumors represent a distinct category of synoviocytic neoplasia, which we term "chondroid synoviocytic neoplasm," rather than simply ordinary TGCT with cartilage. Despite potentially worrisome morphologic features, they appear to behave in at most a locally aggressive fashion.

To examine the multimodality imaging characteristics of parosteal lipomas. With IRB approval, our institutional imaging database and medical record were retrospectively reviewed from 1990–2020 for cases of pathologically-proven and/or imaging diagnosed parosteal lipomas. There were 22 patients (12 males, 10 females) with a mean age of 57.1 ± 12.7 years (range 31–80 years). 11/22 cases (50

The diagnosis of osteoid osteomas (OO) about the hip can be challenging as presenting symptoms can mimic other, more common, periarticular pathologies. Our aims were to identify the most common misdiagnoses and treatments, mean delay in diagnosis, characteristic imaging features and provide tips for avoiding diagnostic imaging pitfalls for patients with OO of the hip. We identified 33 patients (34 tumors) with OO about the hip who were referred for radiofrequency ablation between 1998 and 2020. Imaging studies reviewed included radiographs (n = 29), CT (n = 34), and MRI (n = 26). The most common initial diagnoses were femoral neck stress fracture (n = 8), femoroacetabular impingement (FAI) (n = 7), and malignant tumor or infection (n = 4). The mean time from symptom onset to diagnosis of OO was 15 months (range, 0.4–84). The mean time from initial incorrect diagnosis to OO diagnosis was 9 months (range, 0–46). The diagnosis of OO of the hip is challenging, with up to 70 • The diagnosis of osteoid osteoma of the hip can be challenging, as demonstrated by long delays in time to initial diagnosis and high rates of misdiagnoses which can lead to inappropriate interventions. • Familiarity with the spectrum of imaging features of OO, especially on MRI, is imperative given the increase in the utilization of this modality for the evaluation of young patients with hip pain and FAI. • Consideration of OO in the differential diagnosis of hip pain in adolescent patients and awareness of the characteristic imaging findings, including bone marrow edema and the utility of CT, are critical for making a timely and accurate diagnosis.

Ganglioneuromas are benign neuroblastic tumors seen most in pediatric population. The most common locations are mediastinal, retroperitoneal and adrenal regions. Ganglioneuromas rarely occur in presacral space. We present one such case of an incidentally diagnosed presacral ganglioneuroma in an asymptomatic 71-year-old male who initially presented with hematuria.

Osteoid osteomas typically arise in the long bones of extremities. Patients often report pain relieved by NSAIDS, and radiographic findings are often sufficient for diagnosis. However, when involving the hands/feet, these lesions may go unrecognized or misdiagnosed radiographically due to their small size and prominent reactive changes. The clinicopathologic features of this entity involving the hands and feet are not well-described. Our institutional and consultation archives were searched for all cases of pathologically confirmed osteoid osteomas arising in the hands and feet. Clinical data was obtained and recorded. Seventy-one cases (45 males and 26 females, 7 to 64 years; median 23 years) arose in the hands and feet, representing 12% of institutional and 23% of consultation cases. The clinical impression often included neoplastic and inflammatory etiologies. Radiology studies demonstrated a small lytic lesion in all cases (33/33), the majority of which had a tiny focus of central calcification (26/33). Nearly, all cases demonstrated cortical thickening and/or sclerosis and perilesional edema which almost always had an extent two times greater than the size of the nidus. Histologic examination showed circumscribed osteoblastic lesions with formation of variably mineralized woven bone with single layer of osteoblastic rimming. The most common growth pattern of bone was trabecular (n = 34, 48%) followed by combined trabecular and sheet-like (n = 26, 37%) with only 11 (15%) cases presenting with pure sheet-like growth pattern. The majority (n = 57, 80%) showed intra-trabecular vascular stroma. No case showed significant cytology atypia. Follow up was available for 48 cases (1-432 months), and 4 cases recurred. Osteoid osteomas involving the hands and feet follow a similar age and sex distribution as their non-acral counterparts. These lesions often present with a broad differential diagnosis and may initially be confused with chronic osteomyelitis or a reactive process. While the majority of cases have classic morphologic features on histologic exam, a small subset consists solely of sheet-like sclerotic bone. Awareness that this entity may present in the hands and feet will help pathologists, radiologists, and clinicians accurately diagnose these tumors.

Objective: confluent T1 hypointense marrow signal is widely accepted to represent osteomyelitis on MRI. Some authors have suggested that non-confluent bone marrow signal abnormality should be considered early osteomyelitis. The purpose of this study was to address this issue by comparing the rate of osteomyelitis and amputation based on T1 marrow signal characteristics. Materials and methods: a total of 112 patients who underwent MRI of the foot for the evaluation of possible osteomyelitis were included. Patients were assigned to confluent T1 hypointense, reticulated T1 hypointense, and normal bone marrow signal groups. Results: patients with confluent T1 hypointense signal on MRI had significantly higher rates of osteomyelitis and amputation at 2 and 14 months post-MRI than the reticulated T1 hypointense group ( p<0.001 ). Six patients had normal T1 signal, 16.7 % of whom had osteomyelitis and underwent amputation by 2 months post-MRI. Of 61 patients with reticulated T1 hypointense signal, 19.7 % had a diagnosis of osteomyelitis at 2 months post-MRI and 30.8 % had a diagnosis of osteomyelitis at 14 months post-MRI; moreover, 14.8 % and 31.5 % underwent amputation by 2 and 14 months post-MRI, respectively. Of 45 patients with confluent T1 hypointense signal, 73.3 % of patients had osteomyelitis at 2 months post-MRI and 82.5 % had osteomyelitis at 14 months post-MRI. In this group, 66.7 % underwent amputation by 2 months post-MRI and 77.8 % underwent amputation by 14 months post-MRI. Conclusions: over half of the patients with suspected pedal osteomyelitis who had reticulated or normal T1 bone marrow signal on MRI healed with conservative measures. Therefore, we recommend terminology such as "osteitis", "reactive osteitis", or "nonspecific reactive change" to describe bone marrow edema-like signal and reticulated hazy T1 hypointense signal without associated confluent T1 hypointensity. Moreover, we recommend that the MRI diagnosis of osteomyelitis is reserved for confluent T1 hypointense bone signal in the area of concern.

Objective The accessory sacroiliac joint (ASIJ) is the most common sacroiliac joint anatomical variant; however, its literature-reported prevalence is inconsistent. Previous CT-based studies of the ASIJ have used thick axial slices, which may not adequately detail ASIJ anatomy. The aims of this study are to (1) evaluate ASIJ prevalence and radiographic features in a large age- and sex-balanced cohort using thin-section CT and (2) determine associations between ASIJ anatomy, patient features, and treatment strategies. Materials and methods Thin-section CTs (0.75 to 2.00 mm) of the pelvis from 800 patients were reviewed by two musculoskeletal radiologists. Degree of degenerative change and ankylosis at ASIJs were detailed. The EMR was used to capture demographics, lower back or sacroiliac joint symptoms, and treatments. Results The ASIJ was present in 25.8% of patients and bilateral in 53.3% of those with any ASIJ. ASIJs were more common at the S2 than S1 neural foramen level (75.7% and 27.2%). There was a statistically significant difference between age and presence of any ASIJ anatomy (mean (SD) 69.0 (19.8) with ASIJ versus 55.9 (22.1) years without ASIJ). Degenerative changes and ankylosis were found in 93.5% and 20.3% of ASIJs, respectively. There was a higher odds ratio of having received a sacroiliac joint corticosteroid injection in those with ASIJ anatomy. Conclusion Radiologists should be familiar with the ASIJ and consider its age-related association, propensity to show ASIJ degenerative change, and ability to serve as a potential pain generator. Steroid injections may be considered for diagnostic and therapeutic purposes.

BackgroundCompared to other sarcomas, myxoid liposarcoma (ML) is known to be radiosensitive, with improved oncologic outcomes. Although these tumors "shrink" following radiotherapy, there is a paucity of data examining the degree of radiosensitivity and oncologic outcome. The purpose of the study was to evaluate pre- and postradiotherapy tumor volume to determine if size reduction impacts outcome. MethodsWe reviewed 62 patients with ML undergoing surgical resection combined with preoperative radiotherapy, with pre- and postradiotherapy MRI. This included 34 (55%) males, with a mean age of 47 +/- 14 years. All tumors were deep to the fascia, and 12 (19%) patients had tumors with a >5% round-cell component. ResultsThe mean volume reduction was 54% +/- 29%. Compared to patients with >25% volume reduction, patients with reduction <= 25% had worse 10-year disease specific survival (86% vs. 37%, p < 0.01), in addition to an increased risk of metastatic disease (HR 4.63, p < 0.01) and death due to disease (HR 4.52, p < 0.01). ConclusionLack of volume reduction is a risk factor for metastatic disease and subsequent death due to disease in patients with extremity ML treated with combined preoperative radiotherapy and surgery. This data could be used to stratify patients for adjuvant therapies and follow-up intervals.

Prior case reports have described synchronous ovarian juvenile granulosa cell tumor (JGCT) and enchondromatosis in patients with Ollier disease and Maffucci syndrome. We present a case of a juvenile granulosa cell tumor with an IDH1 somatic mutation identified in the ovarian tissue in a 15-year-old female who presented with abnormal vaginal bleeding, several months of irregular menses, and a large multicystic adnexal mass. Multiple mixed lytic and sclerotic lesions were identified in the bones of the pelvis on imaging studies obtained during the work-up of her abdominal mass. Like previous reports in patients with undiagnosed enchondromatosis, these lesions were presumed to represent skeletal metastases; however, biopsy tissue revealed a hyaline cartilage neoplasm. Subspecialty review of the imaging findings revealed imaging features classic for Ollier disease involving the flat bones of the pelvis. It is important for radiologists to be familiar with the association between enchondromatosis and JGCT. When a female patient with enchondromatosis presents with a large, unilateral, mixed solid-cystic ovarian mass, the diagnosis of JGCT can be suggested. Alternatively, when a patient is diagnosed with JGCT, any skeletal lesions should be scrutinized for imaging features that suggest a hyaline cartilage neoplasm to avoid the misdiagnosis of skeletal metastases in a patient with previously undiagnosed Ollier disease or Maffucci syndrome. To our knowledge, this is the second reported confirmed case of an IDH1 somatic mutation identified in the ovarian tissue of a JGCT in a patient with Ollier disease.