Metastatic TFE3-overexpressing renal clear cell carcinoma with dense granules: a histological, immunohistochemical, and ultrastructural study.

Metastatic TFE3-overexpressing renal clear cell carcinoma with dense granules: a histological, immunohistochemical, and ultrastructural study. Ultrastruct Pathol. 2018 Jul 24;:1-7 Authors: Chen S, Turbat-Herrera EA, Herrera GA, Chadha M, Shackelford RE, Wei EX Abstract This is a case report of a 46-year-old white male who presented with dyspnea. Thoracic and abdominal examinations showed a heterogeneously enhancing mass in the right kidney, multiple pulmonary nodules, and left pleural thickening with large pleural effusion. Pleura biopsy revealed a malignant neoplasm composed of cells with predominantly clear cytoplasm. Considering the large mass in the right kidney, clear cell renal cell carcinoma (RCC) was the main differential diagnosis. The diagnosis in this case was not definitive by histology alone since clear cell RCC markers such as RCC and AE1/AE3 were negative, and CD10 was only focally positive. Transcription factor E3 (TFE3) immunohistochemistry was positive, while the XP11.2 translocation testing was negative. Electron microscopy demonstrated that the tumor cells had abundant cytoplasmic glycogen and lipid, focal long microvilli lining rare lumina, and adjacent interdigitating cell membranes joining the neoplastic cells, indicating a diagnosis of renal clear cell carcinoma. In addition, numerous crystalline-like dense granules were identified in the cytoplasm of the neoplastic cells, which are reminiscent of those typica...
Source: Ultrastructural Pathology - Category: Pathology Authors: Tags: Ultrastruct Pathol Source Type: research