Imprint cytologic features of chromophobe renal cell carcinoma morphologically resembling renal oncocytoma: is this an oncocytic variant of chromophobe renal cell carcinoma?

In this article, we report a case of 76-year-old woman with a rare variant of chromophobe renal cell carcinoma (CRCC). Cytologically, renal tumor cells obtained from imprint cytology were isolated or arranged in small or monotonous population cells with abundant granular cytoplasm. Neoplastic cells showed regular and uniformly shaped small round to oval nuclei with smooth margin. Binucleation was occasionally seen. Immunocytochemically, the cytoplasm of almost all tumor cells was diffusely positive for vimentin and CK 7. Histologically, the cytoplasm was abundant granular eosinophilic and composed of solid cell sheets or pseudoacinar structures. Additionally, tumor cells showed infiltration into some small renal veins covered by a single layer of endothelial cells. These cytological and histological features entirely resembled those of renal oncocytoma. We performed the analysis of von Hippel-Lindau (VHL) gene mutation, 3p loss of heterozygosity (LOH), and fluorescence in situ hybridization (FISH) on chromosomes 7, 10, 13, 17, and 21. As a result, we confirmed monosomy of chromosomes 7, 10, 13, and 17, and these findings corresponded to the diagnosis of CRCC. Finally, we present a case of renal tumor morphologically resembling renal oncocytoma but genetically showing CRCC. We suggest that oncocytic variant of CRCC may actually exist.

Imprint cytologic features in renal cell carcinoma associated with Xp11.2 translocation/TFE3 gene fusion in an adult: a case report.

BACKGROUND: Adult-onset renal cell carcinoma (RCC) associated with Xp11.2 translocation/TFE3 gene fusion is a very rare tumor. To date, there are no reports on immunocytochemical study of the primary tumor. We describe such a case that we diagnosed by immunocytochemistry of imprint cytology material. CASE: A 46-year-old man was found to have a mass in the lower pole of the right kidney. Magnetic resonance imaging (MRI) T2-weighted images showed a hypointense area in the tumor, and papillary RCC was suspected. Imprint cytology showed tumor cells that were isolated or arranged in large or small papillary clusters. Irregularly shaped large oval nuclei, finely granular chromatin and a single large nucleolus were noted. Cytoplasm was abundant and admixed with clear and granular eosinophilic patterns and scattered large vacuolated cells. Almost all tumor cells diffusely expressed immunocytochemical reactivity to TFE3 protein. Hyaline nodules were observed in the stroma. Ultrastructurally, neoplastic cells contained rhomboid crystals identical to those of alveolar soft part sarcoma. CONCLUSION: The immunocytochemistry of TFE3 protein may be a powerful tool for accurate diagnosis when RCC associated with Xp11.2 translocation/TFE3 gene fusion is suspected by imprint cytology even in adult-onset cases, and cytotechnologists should accurately recognize cytologic findings of this tumor.

Paranuclear blue inclusions of small cell carcinoma of the stomach: report of a case with cytologic presentation in peritoneal washings.

BACKGROUND: Primary gastric small cell carcinoma is a rare but important entity. We describe a case that we diagnosed by peritoneal washing cytology. CASE: A 70-year-old male presented with upper abdominal discomfort and underwent endoscopic evaluation. Gastric endoscopy revealed a diffuse, infiltrating tumor from the body to the antrum. Total gastrectomy with lymph node dissection and intraoperative peritoneal washing cytology were carried out. Peritoneal washing cytology showed the presence of many undifferentiated malignant small cells with a necrotic background. The tumor cells were small and round, with naked, hyperchromatic nuclei and finely granular chromatin. Some tumor cells contained paranuclear blue inclusions (PBls) in the cytoplasm. The tumor cells were positive for neuron-specific enolase and synaptophysin on immunocyto-chemistry. Carcinoembryonic antigen, alpha-fetoprotein (AFP) and leukocyte common antigen were negative. Pathologic diagnosis after the operation was moderately to poorly differentiated adenocarcinoma and small cell carcinoma containing AFP-positive cells. CONCLUSION: The prognosis of primary gastric small cell carcinoma is usually poor. Our patient died of multiple liver metastases and peritonitis carcinomatosa 69 days after surgery. When a gastric small cell carcinoma is suspected in peritoneal washings, immunocytochemical demonstration of neuroendocrine differentiation is required to arrive at the final diagnosis.

Primary pulmonary leiomyosarcoma. Report of a case diagnosed by fine needle aspiration cytology.

BACKGROUND: Primary pulmonary leiomyosarcoma is a rare but important entity. We report a case diagnosed by fine needle aspiration cytology. CASE: A 73-year-old male presented with an asymptomatic, right, pulmonary, subpleural nodule detected by computed tomography during follow-up for chronic obstructive pulmonary disease. Fine needle aspiration cytology showed cellular smears with numerous single or loosely cohesive groups of spindle-shaped to round cells. The tumor cell nuclei were blunt ended (cigar shaped), with fine to fine-granular chromatin, prominent nucleoli and an irregular nuclear rim. The tumor cells were positive for desmin and negative for cytokeratin and S-100 protein by immunocytochemistry. Right upper lobectomy with lymph node dissection was performed. Pathologic diagnosis after microscopic, immunohistochemical and electron microscopic studies was leiomyosarcoma. CONCLUSION: To our knowledge, this is the first reported case of primary pulmonary leiomyosarcoma arising in the subpleural region diagnosed by fine needle aspiration cytology. Immunocytochemistry was useful in establishing the diagnosis in this case.