Osteochondromyxoma (OCHM) is an extremely rare benign, sometimes locally aggressive chondroid and osteoid matrix–producing tumour with extensive myxoid changes. It is seen in approximately 1% of patients with Carney complex (CNC) and constitutes one of its 11 diagnostic criteria. We report a case of a 36-year-old man who presented with an incidentally detected chest wall mass. Computed tomography (CT) suggested an osteochondroma. Intraoperatively, a globular, fragile lesion was identified arising from the posterior aspect of the seventh rib, and piecemeal excision was performed. Microscopically, the fragments showed a thick fibrous capsule enclosing mature bony trabeculae and hypocellular marrow spaces, with areas of fibro-myxoid stroma containing short plump to oval spindle cells with bland nuclei, with no atypia, mitoses, or necrosis. Systemic evaluation revealed no spotty skin pigmentation, breast lumps, or thyroid enlargement. Ultrasound of the thyroid and testes, echocardiogram, and adrenal imaging were unremarkable. Endocrine evaluation including serum cortisol, ACTH, and growth hormone levels was normal, excluding syndromic association. Although PRKAR1A mutation analysis, a supplementary criterion for CNC, was suggested, it was not performed. OCHM is an exceedingly rare benign bone tumour with an excellent prognosis following complete excision. Considering the patient’s age and absence of clinical or endocrine features of CNC, this case most likely represents an isolated OCHM. However, long-term multidisciplinary follow-up is essential, as patients may develop diagnostic criteria for CNC in the future.
Introduction and objectives: Programmed death-ligand-1 (PD-L1) is a potential target for immune checkpoint inhibitors in various cancers. The current study aimed to evaluate the concordance of combined positive score (CPS) across 22C3, and SP263 assays when interpreting PD-L1 immunohistochemistry on oesophageal, gastric and gastro-oesophageal junction (GOJ) adenocarcinoma.Methodology: Twenty-two biopsies and eight resection specimens of oesophageal, gastric and GOJ adenocarcinoma were evaluated for PD-L1 SP263 expression at the Department of Pathology, Royal Surrey Hospital, over a period of four years (January 2021 to December 2024). These specimens were re-evaluated for PD-L1 22C3 assay at Poundbury Cancer Institute by an independent pathologist who was blinded to the PD-L1 SP263 assay results. The two results were compared for concordance.Results: There was a very strong positive correlation between the SP263 and 22C3 scores of the two assays (Pearson correlation co-efficiency; r=0.89). Discordance was observed in categorising tumours at cut offs of CPS ≥5 and CPS ≥10, with the discordance being more at a cut off of CPS ≥5.Discussion and conclusion: There are three major commercially available immunohistochemistry assays to quantify PD-L1 expression in cancer cells; SP263, 22C3 and 28-8. A CPS ≥1 is currently used to classify a tumour as PD-L1 positive. According to NICE guidelines, oesophageal or GOJ adenocarcinomas with a PD-L1 CPS ≥5 are eligible for treatment with nivolumab, while a CPS ≥10 qualifies for pembrolizumab therapy. This study demonstrated analytical concordance between the SP263 and 22C3 assays when CPS scoring was applied, consistent with previously published data.
Multicystic renal dysplasia is a rare developmental anomaly of the kidney, often associated with urinary tract obstruction and incompatible with long-term survival when bilateral. Early recognition through antenatal imaging and confirmation by post-mortem examination are crucial for accurate diagnosis and genetic counselling. We present a case of a 31-year-old P2C0 mother who delivered a baby at 36 weeks of gestation. The antenatal ultrasound scan performed at 16 weeks revealed oligohydramnios, and a subsequent foetal anomaly scan showed multicystic kidneys with absent liquor. Further imaging suggested lower urinary tract obstruction, leading to progressive renal impairment and pulmonary hypoplasia. The baby died a few hours after birth. Post-mortem examination revealed a non-syndromic baby with bilateral cystic kidneys, left ureteric atresia, lung hypoplasia, and a large ostium secundum atrial septal defect. Microscopically, both kidneys showed variably sized cysts lined by cuboidal epithelial cells, surrounded by immature mesenchymal stroma with primitive tubules, glomerular structures, and focal cartilage islands. The diagnosis of bilateral multicystic renal dysplasia with left ureteric atresia was made. This case highlights the diagnostic value of foetal autopsy in elucidating the underlying pathology of congenital renal anomalies and its pivotal role in reproductive counselling for future pregnancies.
Cellulose-based materials used in endometriosis surgeries, can trigger histiocytic reactions that mimic mucinous lesions. These two cases highlight diagnostic challenges due to misleading special stain positivity. Accurate biopsy interpretation requires attention to histologic features and detailed surgical history to avoid misdiagnosis.
Background and Objective: The study investigates the effectiveness of a modified Papanicolaou staining method for cervical screening, currently practiced at District General Hospital Matara (DGHM), Sri Lanka, as the conventional method requires a high amount of alcohol.Materials and Methods: A cross-sectional study was conducted from September to November 2023 in the histopathology laboratory at DGHM. A total of 161 cervical smears were collected from Medical Officer of Health (MOH) areas in Matara. Paired smears were stained using both the conventional and modified Pap methods. The modified method involved replacing the alcohol series for hydration with 70% alcohol. After staining with Harris' haematoxylin and rinsing with tap water, the differentiation step in 0.5% HCl and dehydration step with an alcohol series were omitted. Tap water replaced the use of 95% alcohol for rinsing after staining with OG6 and EA50. Smears were air-dried, mounted, and blindly evaluated by the primary investigator, two cyto screeners, and a consultant histopathologist using a standardized scoring system. A quality index was calculated for each method.Results: Out of 152 satisfactory paired smears, 98.7% of conventionally stained and 96.7% of modified-method smears showed distinct cytoplasmic borders. Satisfactory cytoplasmic staining was observed in 60.5% and 57.2% of conventional and modified smears, respectively. All smears showed distinct nuclear borders and crisp chromatin staining. There was no statistically significant difference in cytomorphological quality (p > 0.05). The quality index for the modified and conventional methods was 0.911 and 0.932, respectively. The modified method reduced alcohol use by 80%, resulting in significant cost savings.Conclusion: The modified Pap staining method is a cost-effective, simpler alternative suitable for cervical cytology in resource-limited settings without compromising diagnostic quality.
Endometrial carcinoma with predominant squamous differentiation is rare and poses diagnostic difficulties. Pilomatrix-like high-grade endometrioid carcinoma (PiMHEC) is a recently described aggressive variant, while primary squamous cell carcinoma (PSCC) of the endometrium is also very uncommon. We present two challenging cases comparing their clinicopathological and immunohistochemical features. Two postmenopausal women presenting with vaginal bleeding underwent endometrial sampling followed by total hysterectomy with bilateral salpingo-oophorectomy and sentinel lymph node evaluation. Histopathology and immunohistochemistry were performed, including ER, PR, p53, p16, p40, beta-catenin, and MMR proteins. Case 1 was diagnosed as a PiMHEC, characterized by basaloid nests, ghost cell keratinization, lower-grade glandular components, diffuse nuclear/cytoplasmic beta-catenin expression and MMR proficiency. Focal lymphovascular invasion was observed and nodes were negative. Case 2 was a PSCC showing nests of keratinizing squamoid cells, strong p40 positivity, membranous beta-catenin, negative ER/p16, and extensive lymphovascular invasion with isolated nodal tumour cells. No glandular or pilomatrix differentiation was present and there was no background cervical intraepithelial neoplasia. PiMHEC and PSCC are rare endometrial malignancies that may appear morphologically similar but demonstrate distinct immunophenotypic profiles. Accurate diagnosis requires careful histological assessment, appropriate immunohistochemistry, and exclusion of cervical or metastatic disease. PiMHEC characteristically shows aberrant nuclear and cytoplasmic β-catenin expression, reflecting frequent CTNNB1 mutations, a useful feature for guiding optimal management. Tumours with CTNNB-1 mutation are currently classified in the subset of “no specific molecular profile” category of endometrial carcinomas. Early recognition is essential due to the aggressive clinical behaviour of these tumours.
Meningioma is a common primary central nervous system (CNS) tumour, in which recurrences and local invasion can occur depending on the CNS World Health Organisation (WHO) grade. Extracranial spread of meningioma is rare and mostly includes metastasis to liver, lung, mediastinum and bone. Cervical lymph node involvement is extremely rare and only a few cases have been reported. This is a case of a 57-year-old man, with a diagnosis of CNS WHO grade 2 meningioma who presented with cervical lymph node (level II) enlargement. Microscopically whorls and sheets of cells resembling a meningioma were observed with diffuse EMA positivity. Although it is a rare occurrence, the possibility of metastatic meningioma should be considered in the differential diagnosis of cases of cervical lymph node metastasis, in patients with primary meningioma. Extracranial spread of meningioma carries a relatively poor prognosis. Early diagnosis is important as the excision of primary/secondary disease followed radiotherapy is the currently recommended treatment.
While plasma cell neoplasms typically display overt plasmacytoid morphology, unusual histologic variants can mimic soft tissue tumours such as solitary fibrous tumour (SFT). Critically, SFTs lack plasmacytoid differentiation, which is a key distinguishing feature. We present two cases in which plasma cell neoplasms mimicked SFT histologically, underscoring the importance of recognizing this pitfall.Case 1: A L1-L2 lytic lesion in a 46-year-old woman was diagnosed on biopsy as SFT due to the presence of a "patternless" spindle-cell proliferation with hemangiopericytoma-like vessels. Excision revealed focal plasmacytoid cells, a feature that is not in keeping with SFT. This prompted immunohistochemistry (IHC) testing, which showed that the tumour cells were CD138+ plasma cells, confirming a plasma cell neoplasm.Case 2: A 41-year-old man presented with a L2 fracture, that on histology exhibited a vascular tumour with staghorn vessels and diffuse plasmacytoid morphology. Further evaluation with IHC (CD138+) and serum analysis led to a diagnosis of multiple myeloma.These cases demonstrate that plasmacytoid morphology, even if focal, should prompt consideration of plasma cell neoplasms. Pathologists must recognize this distinction, particularly in vascular-rich spindle-cell lesions, as misdiagnosis delays appropriate treatment.
Introduction: Gastric and gastro-oesophageal junction (GOJ) adenocarcinoma is the fifth most common cancer and fourth leading cause of cancer death globally. HER2 overexpression occurs in 13-22% of gastric and 30% of GOJ adenocarcinoma.Objective: This was a retrospective study of HER2 (4B5) expression in gastric, oesophageal and GOJ adenocarcinoma reported at a single centre in the United Kingdom. HER2 (4B5) immunohistochemistry (IHC), in situ-hybridization(ISH) status and other pathological data of gastric and GOJ adenocarcinomas reported in both biopsies and resection specimens were collected from January 2014 to December 2022.Results: A total of 481 patients were included in the study. The median age of patients at the time of surgery was 67.7 years; 68.2% were male. The proportion of patients with of HER2 (4B5) positivity was 13.30% (64/481) . Most HER2 positive tumours were grade 2 (G2) and of intestinal subtype (50%). Of the HER2 positive tumours, most were located at GOJ/Cardia (31; 48.43%), were pT1b (9/64, 39.13%) stage and showed nodal positivity (pN1) (12/64, 52.2%). HER2 assessment had been performed on both biopsies and subsequent resection specimens in 100 patients of which 95 (95%) cases showed concordance of HER2 results. The discordance was mainly due to tumour heterogeneity.Conclusion: The overall prevalence of HER 2 positivity was 13.30%. HER2 positivity was associated with intestinal subtype rather than diffuse subtype of adenocarcinoma. Tumour heterogeneity was identified as a cause for cases of discordance of HER expression between biopsy and resection specimens.
