Patrick A. Candy¹, Anuruddha Gallappatige¹, Prasantha Durbhakula¹ 

¹Northern Tasmanian Pathology Service, Launceston General Hospital, Launceston, Tasmania, Australia. 

Oncocytic adrenocortical carcinoma (ACC) is a rare, aggressive subtype of ACC, presented in this case report¹. A 54-year-old man was found to have an incidental 25mm left adrenal tumour on CT for a spinal injury. Tumour was non-functional based on urine and serology testing. A laparoscopic adrenalectomy was performed, because of tumour enlargement. Grossly, it was a 45mm, 40 gram, solid, tan/grey tumour. Histology showed a diffuse growth of oncocytic cells with brightly eosinophilic cytoplasm and pleomorphic, hyperchromatic nuclei. Cells were positive for Melan-A, synaptophysin and calretinin, and negative for CD10, chromogranin, PAX8 and Vimentin. This immunoprofile is consistent with ACC, excluding differentials of pheochromocytoma and chromophobe renal cell carcinoma. High-risk features per the Lin-Weiss-Bisceglia system, were atypical mitoses, necrosis, >5 mitoses/50HPF, and a focus suspicious for venous invasion². Ki67 index was 10% (>5% indicates malignancy) and the reticulin meshwork was disrupted. B-catenin and p53 immunohistochemistry, showed a good prognostic pattern, with negative nuclear B-catenin expression and P53 wild type³. Metastatic disease was excluded by PET/CT and mitotane chemotherapy commenced. In summary, oncocytic ACC is a rare, distinct subset of adrenal neoplasia, that differs from conventional ACC, requiring the Lin-Weiss-Bisceglia system and immunohistochemistry to characterise its malignant potential and prognosis.

References:

1. Mearini L, Del Sordo R, Costantini E et al. Adrenal oncocytic neoplasm: a systematic review. Urol Int 2013;91:125–33. 10.1159/000345141

 

2. Bisceglia M, Ludovico O, Di Mattia A et al. Adrenocortical oncocytic tumors: Report of 10 cases and review of the literature. Int J SurgPathol 2004;12:231–43.

 

3. Gan W, Han X, Gong Y, et al. Diagnostic and prognostic assessments of adrenocortical carcinomas by pathological features, immunohistochemical markers and reticular histochemistry staining. Diagn Pathol. 2024 May 27;19(1):71.

 

Patrick Candy declares that this abstract and poster are the product of his own work. He wrote this case’s abstract, designed and created the poster, and made the microscopic photos. He reviewed the slides and contributed to the microscopic report for this case. Generative AI has not been used in the creation of this abstract and poster.