Luan Truong

Renal cell carcinoma: Evolving and emerging subtypes

Our knowledge of renal cell carcinoma (RCC) is rapidly expanding. For those who diagnose and treat RCC, it is important to understand the new developments. In recent years, many new renal tumors have been described and defined, and our understanding of the biology and clinical correlates of these tumors is changing. Evolving concepts in Xp11 translocation carcinoma, mucinous tubular and spindle cell carcinoma, multilocular cystic clear cell RCC, and carcinoma associated with neuroblastoma are addressed within this review. Tubulocystic carcinoma, thyroid-like follicular carcinoma of kidney, acquired cystic disease-associated RCC, and clear cell papillary RCC are also described. Finally, candidate entities, including RCC with t(6;11) translocation, hybrid oncocytoma/chromophobe RCC, hereditary leiomyomatosis and RCC syndrome, and renal angiomyoadenomatous tumor are reviewed. Knowledge of these new entities is important for diagnosis, treatment and subsequent prognosis. This review provides a targeted summary of new developments in RCC.

Intraoperative consultation for renal lesions: Implications and diagnostic pitfalls in 324 cases

Intraoperative consultation rarely is requested for lesions in the kidney. Of 324 renal lesions submitted for gross or frozen section intraoperative consultation, 199 specimens were submitted for gross consultation only; no diagnostic pitfalls were noted. The clinical implications and diagnostic pitfalls in 125 specimens submitted for frozen section were the focus of our study. Frozen section intraoperative consultation was requested to evaluate surgical margins in partial nephrectomy specimens, solid renal mass in an unusual clinical or radiologic setting, synchronous renal and extrarenal masses, cystic renal lesion, ureteral surgical margins for transitional cell carcinoma, multiple renal masses, solid mass in a diffusely cystic kidney, and renal injury. Among the 125 cases, the diagnoses were deferred in 17 (6 renal cell carcinomas with granular cytoplasm, 7 cystic lesions, 3 metastatic tumors, 1 leiomyoma). The frozen section diagnoses were incorrect owing to limited sampling in 5 and misinterpretation in 4 (melanoma vs angiomyolipoma, lymphoma vs angiomyolipoma, benign cyst vs cystic renal cell carcinoma, metastatic renal cell carcinoma vs pheochromocytoma). Awareness of distinctive indications for frozen section intraoperative consultation and diagnostic pitfalls should improve diagnostic accuracy and facilitate proper management of these lesions.

Intraoperative Consultation for Renal Lesions

Intraoperative consultation rarely is requested for lesions in the kidney. Of 324 renal lesions submitted for gross or frozen section intraoperative consultation, 199 specimens were submitted for gross consultation only; no diagnostic pitfalls were noted. The clinical implications and diagnostic pitfalls in 125 specimens submitted for frozen section were the focus of our study. Frozen section intraoperative consultation was requested to evaluate surgical margins in partial nephrectomy specimens, solid renal mass in an unusual clinical or radiologic setting, synchronous renal and extrarenal masses, cystic renal lesion, ureteral surgical margins for transitional cell carcinoma, multiple renal masses, solid mass in a diffusely cystic kidney, and renal injury. Among the 125 cases, the diagnoses were deferred in 17 (6 renal cell carcinomas with granular cytoplasm, 7 cystic lesions, 3 metastatic tumors, 1 leiomyoma). The frozen section diagnoses were incorrect owing to limited sampling in 5 and misinterpretation in 4 (melanoma vs angiomyolipoma, lymphoma vs angiomyolipoma, benign cyst vs cystic renal cell carcinoma, metastatic renal cell carcinoma vs pheochromocytoma). Awareness of distinctive indications for frozen section intraoperative consultation and diagnostic pitfalls should improve diagnostic accuracy and facilitate proper management of these lesions.

PAX2 and PAX8: Useful Markers for Metastatic Effusions

Objective: It was the aim of this study to determine the utility of PAX2 and PAX8 in cytology effusions with metastatic tumor. Study Design: PAX2 and PAX8 immunohistochemical staining was performed on cell blocks of 89 pleural, pericardial and peritoneal effusions with benign diagnoses (18 cases), or secondary to renal cell carcinoma (RCC; 9 cases), müllerian carcinoma (21 cases) or non-müllerian carcinoma (41 cases). Results: PAX2 stained 0% (0/18) of controls, 100% (8/8) of RCCs, 35% (7/20) of müllerian carcinomas, and 2% (1/41) of non-müllerian carcinomas. PAX8 stained 6% (1/18) of control cases, 100% (9/9) of RCC cases, 100% (20/20) of müllerian carcinomas, and 5% (2/41) of non-müllerian carcinomas. PAX2 was 35% sensitive and 95% specific for müllerian carcinoma and 100% sensitive and 95% specific for RCC. PAX8 was 100% sensitive and 95% specific for müllerian carcinoma and 100% sensitive and 95% specific for RCC. Conclusions: PAX8 is more sensitive than PAX2 for metastatic effusions from müllerian carcinomas (100 vs. 35%), while also having a higher intensity of staining than PAX2. However, PAX2 and PAX8 are both highly sensitive and specific for RCCs. PAX2 and PAX8 are valuable diagnostic markers for metastatic müllerian carcinomas and RCCs in effusion cytology. PAX8 is superior for carcinomas of müllerian origin.

Spheroid-type of AL amyloid deposition associated with colonic adenocarcinoma: A case report with literature review: Spheroid-type amyloid in colon

We report a colonic adenocarcinoma associated with diffuse submucosal deposition of a peculiar spheroid‐type amyloid identified in the colon, terminal ileum, and appendix. A 65‐year‐old woman with past medical histories of hypertension, and chronic obstructive pulmonary disease, presented to the emergency room with cramping abdominal pain and nausea. A computed tomography (CT) scan of abdomen showed right colonic volvulus. Emergency right hemicolectomy was performed. The specimen showed colonic adenocarcinoma with focal submucosal invasion (pT1) arising from a villotubular adenoma. A diffuse submucosal spheroid‐type amyloid deposition (resembling corpora amylacea‐like structures with Liesegang ring formation) was identified in the colon, ileum, and appendix. Electron microscopy examination of this unusual spheroidal‐type material further confirmed the presence of amyloid fibrils. Analysis by liquid chromatography–mass spectrometry detected AL (lambda) type amyloidosis in this specimen. Tests for monoclonal gammopathy were not performed because patient consent was not obtained. In tissue section evaluation, however, no plasma cell neoplasm was identified. Cases with isolated AL amyloid deposition in the gastrointestinal tract have been reported rarely, and there is no case report of colonic adenocarcinoma associated with primary amyloid deposition in the English literature.

Sarcoid-like granulomas in renal cell carcinoma: The Houston Methodist Hospital experience

Sarcoid-like (SL) granulomas have been previously described in association with malignant tumors. These granulomas appear to be tumor-related but are not indicative of systemic sarcoidosis, and hence are referred to as SL reactions. These SL reactions can be seen within the primary tumor, its vicinity, or in uninvolved sites such as the spleen, bone marrow, skin, and/or regional lymph nodes draining the tumor. It is a widely held view that SL granulomas are caused by soluble antigenic factors, shed by tumor cells or released due to tumor necrosis. SL reactions reported in Hodgkin lymphoma have been associated with a better prognosis. SL granulomas are thought to play an important role in the hosts defenses against metastatic extension. SL granulomas have been reported in approximately 4.4% of carcinomas. Isolated cases of renal cell carcinoma (RCC) with SL granulomas have been reported with questionable prognostic significance. We identified 11 cases of RCCs with SL granulomas. Interestingly, all cases had abundant clear cell cytoplasm (10 clear cell RCC cases and 1 clear cell papillary RCC). We propose that this clear, abundant cytoplasm of the tumor cells with high content of glycogen and lipids may trigger granuloma formation akin to that seen in seminomas with SL granulomas. To date, this is the largest case series of RCCs with SL granulomas.