Diagnostic Approach to Eosinophilic Renal Neoplasms

Abstract

Context Eosinophilic renal neoplasms include a spectrum of solid and papillary tumors ranging from indolent benign oncocytoma to highly aggressive malignancies. Recognition of the correct nature of the tumor, especially in biopsy specimens, is paramount for patient management. Objective To review the diagnostic approach to eosinophilic renal neoplasms with light microscopy and ancillary techniques. Data Sources Review of the published literature and personal experience. Conclusions The following tumors are in the differential diagnosis of oncocytic renal cell neoplasm: oncocytoma, chromophobe renal cell carcinoma (RCC), hybrid tumor, tubulocystic carcinoma, papillary RCC, clear cell RCC with predominant eosinophilic cell morphology, follicular thyroid-like RCC, hereditary leiomyomatosis–associated RCC, acquired cystic disease–associated RCC, rhabdoid RCC, microphthalmia transcription factor translocation RCC, epithelioid angiomyolipoma, and unclassified RCC. In low-grade nonpapillary eosinophilic neoplasms, distinction between oncocytoma and low-grade RCC mostly rests on histomorphology; however, cytokeratin 7 immunostain may be helpful. In high-grade nonpapillary lesions, there is more of a role for ancillary techniques, including immunohistochemistry for cytokeratin 7, CA9, CD10, racemase, HMB45, and Melan-A. In papillary eosinophilic neoplasms, it is important to distinguish sporadic type 2 papillary RCC from microphthalmia transcription factor translocation and hereditary leiomyomatosis–associated RCC. Histologic and cytologic features along with immunohistochemistry and fluorescence in situ hybridization tests for TFE3 (Xp11.2) and TFEB [t(6;11)] are reliable confirmatory tests. Eosinophilic epithelial neoplasms with architecture, cytology, and/or immunoprofile not qualifying for either of the established types of RCC should be classified as unclassified eosinophilic RCC and arbitrarily assigned a grade (low or high).

Clinicopathological study of 5 cases of renal cell carcinoma with t(6;11)(p21;q12)

“…A tubulocystic pattern was also reported previously, but this phenomenon seems to be very rare [20]. Histologically, this tumor is chiefly composed of two kinds of neoplastic cells of both large cells resembling usual clear cell RCC cells and small cells simulating lymphocytes [21,22,23,24]. This finding seems to be a most important diagnostic clue.…”

“…This tumor shows overexpression of TFEB protein because of the formation of the Alpha-TFEB chimeric transcript caused by chromosomal translocation between 6p21 and 11q12, and nuclear expression of TFEB is a highly sensitive and specific diagnostic marker [7]. The combined immunohistochemical stainings for cathepsin K, melanosome-related antigen (clone HMB45) and melan A seem to be an adjunctive diagnostic tool in identification of RCC with t(6;11)(p21;q12) [4,6,7,11,13,15,16,18,19,20,21,22,23,24,27,28]. The break-apart FISH study for the TFEB gene seems to be an excellent measure for the definite diagnosis because the fusion partner for the TFEB gene is limited to the Alpha (MALAT) gene [17,20,23,28,29].…”

“…The combined immunohistochemical stainings for cathepsin K, melanosome-related antigen (clone HMB45) and melan A seem to be an adjunctive diagnostic tool in identification of RCC with t(6;11)(p21;q12) [4,6,7,11,13,15,16,18,19,20,21,22,23,24,27,28]. The break-apart FISH study for the TFEB gene seems to be an excellent measure for the definite diagnosis because the fusion partner for the TFEB gene is limited to the Alpha (MALAT) gene [17,20,23,28,29]. This fact essentially seems to differ from that of Xp11.2/TFE3 translocation-associated RCC having several fusion partners [1,2,3,4,5,21,30].…”

Eosinophilic Granulomatosis with Polyangiitis Associated to Chromophobe Renal Cell Carcinoma: A Case Report

“…On radiographic exams, chRCC appears as a well-defined and homogeneous mass, scarcely invading perinephric tissue or blood vessels [24]. Usually, patients are diagnosed in early stages (T1 or T2), being frequently cured surgically, with good prognosis [24][25][26]. All these clinical and epidemiological features were found in the patient here described.…”

“…Chromophobe renal cell carcinoma (chRCC) is a rare renal neoplasm, accounting for 5% of renal tumors [23][24][25]. It affects men twice more often than women, more commonly between sixth and eighth decades of life.…”