Parenchymal splenic metastases from solid malignancies are infrequent, often clinically silent, and usually present in the setting of widespread systemic metastases. Imaging characterisation is limited and challenging because of overlapping features with inflammatory pathologies and primary splenic neoplasms. This retrospective case series included six patients with solid malignancies who demonstrated splenic lesions on 18F-FDG PET/CT between 2016 and 2025. Imaging was evaluated for morphology, metabolic activity (SUVmax), and extra-splenic disease. Histopathological confirmation was available in one operated case, while the diagnosis in the remaining patients was based on imaging and clinical context. Primary malignancies included renal cell carcinoma (n = 2), breast carcinoma (n = 1), lung carcinoma (n = 1), hepatocellular carcinoma (n = 1), and ovarian carcinoma (n = 1). Splenic lesions were associated with systemic metastatic disease in most patients. Lesions were isodense to hypodense on CT and showed variable FDG uptake (SUVmax range: ~3.8 -15.5). In patients with widespread disease, splenic involvement was interpreted as metastatic based on imaging patterns. Histopathological confirmation was available in one case. 18 F-FDG PET/CT unveils clinically occult splenic metastases and provides whole-body disease burden. Although imaging patterns, along with clinical context, may suggest metastatic disease, histopathological confirmation is recommended for solitary or indeterminate lesions, as it may contribute to therapeutic decision-making.
Inguinal bladder hernia is a rare condition that accounts for 1-3% of all inguinal hernias. It is mostly asymptomatic and is incidentally detected during surgical repair of an inguinal hernia. Ultrasonography and abdominopelvic computed tomography (CT) scans are the usual imaging modalities used as part of the work-up of this hernia. Open surgical repair is the most commonly used treatment. We present a rare case of an inguinal bladder hernia, aka inguinoscrotal cystocele, to be incidentally detected on a whole-body 18 F-fluorodeoxyglucose positron emission tomography-CT scan and highlight it as a teaching point for nuclear medicine physicians.
Klippel–Trenaunay syndrome (KTS) is a rare congenital vascular disorder characterised by capillary, venous, and lymphatic malformations associated with soft-tissue and/or bony hypertrophy, predisposing affected individuals to complications such as chronic lymphoedema, bleeding, and functional impairment. Although KTS is predominantly considered a benign condition, rare malignant neoplasms, including squamous cell carcinoma, angiosarcoma, rhabdomyosarcoma, and adenocarcinoma, have been reported in affected tissues. To the best of our knowledge, synovial sarcoma arising in a KTS-affected limb has not been previously reported. This case highlights the diagnostic challenges posed by coexisting vascular malformations, which may obscure the early detection of malignant transformation, and emphasises the importance of vigilant clinical and imaging surveillance. Furthermore, it underscores the value of multimodality imaging, particularly 18 F fluorodeoxyglucose positron emission tomography/computed tomography ( 18 F FDG PET/CT), in the detection, staging, and assessment of metastatic disease in synovial sarcoma arising in the setting of KTS.
Objectives: Serum thyroglobulin (TG) measurement is essential for long-term monitoring of differentiated thyroid cancer (DTC) following total thyroidectomy. Although isotopic assays are considered the gold standard, non-isotopic methods are increasingly adopted due to logistical advantages. Despite the availability of an international TG standard (certified reference material CRM-457), complete assay standardisation and interchangeability remain unachieved Camel-derived polyclonal anti-TG antibodies have been rarely explored in immunoradiometric assay (IRMA) formats. The in-house IRMA developed using these antibodies was previously validated against a commercial IRMA (TG IzotopR) kit; this study further evaluates its analytical and clinical performance against a standard electrochemiluminescence immunoassay (ECLIA) to assess cross-platform comparability. Material and Methods: In this cross-sectional comparative study, TG levels were measured using an in-house IRMA and Roche Eleusis TG II ECLIA in 157 anonymised leftover serum samples from DTC patients (age 11–79 years; male: female ~1:2), stored at −20 °C. The in-house IRMA uniquely employs camel-derived polyclonal anti-TG antibodies for capture and 125I-labelled monoclonal antibodies for detection. Method comparison was performed using linear regression and Bland–Altman analysis. Results: The analytical ranges were 0.04–500 ng/mL (ECLIA) and 0.1–300 ng/mL (IRMA). A moderate positive correlation was observed ( r = 0.51, n = 157, p <0.001) with the regression equation Y = 0.18X + 4.8, indicating limited agreement. Bland–Altman analysis demonstrated an overall positive bias, with IRMA slightly overestimating TG, particularly at low concentrations. Conclusion: Despite analytical differences, clinical decision-making was not significantly affected. However, consistent use of a single assay is crucial for longitudinal TG monitoring due to limited inter-assay comparability. The in-house IRMA has been used routinely for over 12 years in approximately 50,000 samples, supporting its practical utility. Its cost-effectiveness and sustainability, along with inherent variability between radio isotopic and nonisotopic platforms, underscore the importance of assay consistency in DTC follow-up.
We report a case of a middle-aged woman who initially presented elsewhere with left elbow pain, whose initial MRI revealed an expansile lytic lesion in the proximal ulna. The first biopsy report done was misinterpreted as a giant cell tumour. Upon referral to our centre, further evaluation established the diagnosis of brown tumour secondary to primary hyperparathyroidism. Notably, while the Tc- 99 m Sestamibi scan showed uptake at the site of parathyroid adenoma, it failed to show uptake in the bone lesions, while 68 Ga RGD PET/CT revealed uptake in the multiple sites of brown tumours, suggesting a unique pattern of metabolic inactivity but persistent vascularity in the bone lesions. This case demonstrates the interplay of different biological pathways unlocked by advanced nuclear imaging in detecting brown tumours based on their evolving biological behaviour.
Precise diagnosis of deep pelvic malignancies in patients is challenging due to complex anatomy and limited access. This case series explores the feasibility and accuracy of trans gluteal robot-assisted PET/CT-guided biopsy to overcome such limitations. All three patients underwent a focused regional PET/CT scan of the pelvis using the GE Discovery 690 PET/CT system, 40 minutes post-injection of 2–3 mCi of 18 F FDG. Due to deep pelvic lesion locations, a trans gluteal robotic-assisted approach was selected. Pre-procedural assessment included hemogram and PT INR testing. Patients were prepared with a high-fibre diet and a phosphate enema for bowel clearance. Robotic planning software was used for needle trajectory mapping based on SUVmax, optimising target localisation while avoiding critical structures. Biopsies were performed under PET/CT guidance. All three procedures were technically successful and led to histopathological confirmation of malignancy. The approach demonstrated superior lesion accessibility and patient safety with minimal complications. Transgluteal robot-assisted PET/CT-guided biopsy provides a minimally invasive, precise diagnostic technique for pelvic malignancies, potentially improving diagnostic yield and guiding personalised treatment.
Objectives: To evaluate the role and clinical utility of FDG PET/CT in the detection of extrathoracic distant metastases (DM) in recurrent head and neck squamous cell carcinoma (HNSCC) and to identify high-risk clinical predictors for systemic spread. Material and Methods: Data of 500 patients with histopathologically proven recurrent HNSCC who underwent FDG PET/CT for restaging between January 2010 and June 2018 were analysed. Findings were validated by histopathology, follow-up imaging or multidisciplinary consensus. Statistical correlation was performed for various predictors of distant metastases, like initial TNM stage, primary site, disease-free interval (DFI), and clinical recurrent stage (crTNM). The impact of restaging PET/CT on management decisions was also studied. Results: DM were identified in 144/500 patients (28.8%), with 54 patients (10.8% of the total cohort) presenting with isolated extrathoracic metastases, which altered clinical management. FDG PET/CT demonstrated 100% sensitivity and 99.5% specificity for DM detection. Significant predictors for DM included advanced initial TNM stage, initial N-stage, shorter DFI, and advanced crTNM stage ( p < 0.05). Conclusion: There is a high incidence of distant metastases in recurrent HNSCC, with a significant proportion occurring as isolated extrathoracic disease. 18 F-FDG PET/CT significantly impacts management by unmasking systemic spread missed by regional CT protocols. We recommend that PET/CT should be used for restaging in a high-risk subset of head-neck cancer patients defined by advanced initial staging and a short disease-free interval
Capicua transcriptional repressor ( CIC )-rearranged sarcomas are exceedingly rare and highly aggressive malignancies affecting young individuals predominantly, and CIC::NUTM1 is thought to be a molecular variant of CIC-rearranged sarcoma. It has a poor prognosis and a rapid progression. Here, we present a case of a 3-year-old male with CIC::NUTM1 sarcoma of the pelvis who presented with complaints of constipation associated with severe pain for which 18 F fluorodeoxyglucose positron emission tomography/computed tomography was done as a part of diagnostic workup.
Extramedullary relapse of multiple myeloma (MM) involving both the skin and pleura is exceptionally uncommon and is associated with an aggressive clinical course and poor prognosis. We report a 42-year-old man with newly diagnosed ISS stage III MM who initially presented with extensive FDG-avid skeletal lesions, a large anterior mediastinal plasmacytoma, and pleural deposits on baseline 18 F-FDG PET/CT. Following induction and consolidation chemotherapy, the patient achieved a stringent complete response with disappearance of the monoclonal protein and bone marrow remission. However, subsequently developed rapidly progressive extramedullary relapse manifesting as multiple cutaneous chest wall plasmacytomas and myelomatous pleural effusion. Cytological and histopathological examination confirmed plasma cell infiltration. Follow-up FDG PET/CT examinations accurately delineated the extent of disease, guided biopsy from the metabolically active lesions, assessed treatment response, and demonstrated partial metabolic response following salvage chemotherapy, although the disease ultimately progressed despite multiple lines of therapy including VTD-PACE and venetoclax. The patient eventually succumbed to progressive disease. This case highlights the aggressive biology of extramedullary MM, the rarity of synchronous cutaneous and pleural involvement, and underscores the indispensable role of FDG PET/CT in staging, treatment planning, response assessment, and prognostication in patients with refractory extramedullary disease.
Fibroblast activation protein inhibitor (FAPI) PET/CT has emerged as a novel imaging technique for fibroblast-driven pathology. Orbital fibroblast activation is central to the pathogenesis of Graves’ ophthalmopathy (GO), making fibroblast activation protein (FAP) a mechanistically appropriate molecular target. We report a case of a 59-year-old female with steroid-refractory active GO (clinical activity score 6/7) who underwent 68 Ga 46 FAPI PET/CT, which demonstrated tracer accumulation in bilateral extraocular muscles with a topographic distribution consistent with known disease anatomy. Imaging findings correlated with high disease activity despite immunosuppressive therapy, suggesting
Accurate breast cancer staging using 18 F FDG PET/CT is crucial, though benign inflammatory conditions can yield false-positive results mimicking metastasis. We present a 44-year-old woman with newly diagnosed invasive ductal carcinoma who underwent a baseline PET/CT. Imaging revealed the primary tumour, axillary node involvement, and an unexpected hypermetabolic nodule in the anterior abdominal wall. Highly suspicious for a metastatic deposit, this finding threatened to inappropriately upstage the patient to Stage IV, which would shift her treatment from curative to palliative intent. An ultrasound-guided core biopsy was performed, and histopathology definitively diagnosed abdominal wall endometriosis, ruling out distant metastasis. This confirmation allowed the patient to safely proceed with a curative-intent mastectomy. This case underscores the necessity of tissue biopsy for isolated hypermetabolic findings to prevent erroneous cancer upstaging.
Renal cell carcinoma (RCC) is extremely rare in the paediatric population. It accounts for only 0.3-1.3% of all paediatric tumours. Amongst renal tumours in the paediatric population, it contributes only a minuscule 2-6%, while Nephroblastoma accounts for 86-87%. These tumours also differ in terms of histology and the mutations that result in their origin based on the age of onset. Here, we present a case of renal cell carcinoma in a 6-year-old girl. She presented with left-sided abdominal pain and a mass on examination. A provisional diagnosis of neuroblastoma was made, considering the clinical presentation- paediatric age group with an abdominal mass. 18 F 2-Fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) was performed. However, the scan showed an irregular renal mass with low-grade FDG avidity and enlarged para-aortic nodes. Total nephrectomy and lymph node excision were performed, and postoperative histopathology confirmed the diagnosis of RCC with nodal metastases. Being rare, paediatric RCC is not well documented, and results from adult studies are applied to paediatric patients in common practice. This case report emphasises the need for more clinical studies regarding the common presentations, patterns of spread and outcomes of RCC in children.
Gallbladder carcinoma contributes 50% of biliary tract cancers. Its gradual onset and nonspecific early symptoms often delay diagnosis, making early detection and treatment vital for better outcomes. Ga-68-labelled fibroblast activation protein inhibitor (FAPI), an emerging positron emission tomography (PET) tracer, has demonstrated its diagnostic superiority over F-18-fluorodeoxyglucose PET/computed tomography (F-18-FDG PET/CT) in the detection of primary and metastatic lesions across various malignancies. Here, our case represents the superiority of Ga-68 FAPI PET/CT over the F-18-FDG PET/CT scan in the detection of the carcinoma gallbladder.
Choroidal metastasis is a rare manifestation of systemic malignancy, often occurring late in the disease course. Here, we present a case of a 67-year-old male who presented with a solitary choroidal metastasis as the initial symptom of lung adenocarcinoma. The patient underwent systemic chemotherapy with a remarkable response, highlighting the importance of early diagnosis and aggressive treatment of metastatic disease.
An 89-year-old male with newly diagnosed prostate cancer underwent routine bone single photon emission computed tomography (SPECT) imaging. The scan revealed increased technetium-99m methylene diphosphonate ( 99 Tcm-MDP) uptake in the anterior segment of the left 9th rib, the 8th thoracic vertebra, and the right pubic region, raising suspicion of widespread osseous metastases. Previous chest computed tomography (CT) showed definite fractures of the left 9th rib and 8th thoracic vertebrae, so we suspected that the MDP concentration in the right pubic region might be due to other causes as well. Subsequent SPECT/CT fusion imaging diagnosed the MDP-concentrating foci at this site as an inguinal bladder hernia.
Objectives: Diabetic foot osteomyelitis (DFO) is a leading cause of non-traumatic lower limb amputations. While magnetic resonance imaging (MRI) and plain radiographs are common, their specificity is often limited by neuroarthropathic changes (Charcot foot). This prospective study evaluated the diagnostic utility of Tc-99m HMPAO labelled leucocyte scintigraphy combined with single photon emission computed tomography - computed tomography (SPECT-CT) in identifying DFO, using bone biopsy as the reference standard. Material and Methods: The study was conducted between 2015 and 2017 at a tertiary care hospital in South India. Thirty diabetic patients with 35 suspected infected foot ulcers were enrolled. Patients underwent plain radiography followed by labelled leucocyte scintigraphy. Images were acquired at 30 minutes (quality check), 4 hours (planar and SPECT-CT), and 24 hours. Bone biopsies were performed on 17 ulcers for histopathological and microbiological confirmation. Results: The median labelling efficiency of the leucocytes was 42.3%. SPECT-CT demonstrated superior contrast and localisation compared to planar imaging, identifying focal uptake in four ulcers that appeared negative on 4-hour planar scans. Of the 17 biopsied ulcers, 5 were confirmed as osteomyelitis via histopathology. The combined WBC scintigraphy and SPECT-CT yielded a sensitivity of 60% and a specificity of 100%. Conclusion: Labelled leucocyte scintigraphy with SPECT-CT is a highly specific, non-invasive imaging modality for DFO. Its ability to accurately differentiate soft tissue infection from bone involvement makes it a powerful tool for ruling out osteomyelitis and guiding surgical biopsies, particularly when conventional radiological findings are ambiguous.
