Can renal oncocytoma be distinguished from chromophobe renal cell carcinoma by the presence of fibrous capsule? Demirović A, Cesarec S, Spajić B, Tomas D, Bulimbašić S, Milošević M, Marušić Z, Krušlin B. Virchows Arch. 2009 Dec 19. PMID: 20024582

Ljudevit Jurak University, Department of Pathology, Sestre Milosrdnice University Hospital, Vinogradska cesta 29, Zagreb, Croatia.

The most important differential diagnosis of chromophobe renal cell carcinoma (CRCC) is renal oncocytoma. Due to overlapping morphological characteristics of renal oncocytoma and CRCC, particularly its eosinophilic variant, making a correct diagnosis can be challenging. To date, no data are available on the presence of the tumor fibrous capsule as a diagnostic feature in differentiating these tumors. The main purpose of this study was to establish the presence and compare the thickness of the tumor fibrous capsule between two tumor groups. A total of 37 tumors-18 cases of CRCC (three eosinophilic and 15 classic) and 19 cases of renal oncocytoma-were analyzed. Four slides of each tumor stained with hematoxylin and eosin were first scanned at low-power magnification (x40) to assess the presence of the capsule. If present, the capsule was measured in three different thickest areas at higher magnification (x200). The mean value of capsule thickness was calculated and taken into consideration. The capsule was present in 12 (66.7%) cases of CRCCs and in only two (10.5%) cases of renal oncocytomas. Statistical analysis showed significant difference between the presence of fibrous capsule in these two observed tumor groups (P = 0.001). Average thickness of capsule in CRCCs was 337.7 mum, and 115.4 mum in renal oncocytomas, but the median was not statistically significant (P = 0.198). Studies with a larger number of cases are needed to conclude if this characteristic could be a low-cost, reliable microscopic feature in differentiating between CRCC and renal oncocytoma.

PMID: 20024582

Infiltrating glomus tumor of uncertain malignant potential arising in the kidney.

Gill J, Van Vliet C. Hum Pathol. 2009 Nov 5. PMID: 19896698


Diagnostic Medlab, Surgical Pathology, Auckland, 1060 New Zealand.

Glomus tumors closely resemble the normal glomus body and have a predilection for skin and subcutaneous tissue. These tumors rarely present in visceral organs. We report a case involving the kidney. This glomus tumor displays typical cytology and immunohistochemical profile of glomus tumors elsewhere. However, this tumor is large, has a deep location and exhibits an infiltrative margin and increased mitotic activity. These features, by current definition, would suggest malignant behavior. However, the rarity of such an entity in the kidney highlights the need for caution and a diagnosis in a continuum between benignity and malignancy. To the best of our knowledge, this report is the first case of infiltrating glomus tumor or glomus tumor of uncertain malignant potential arising in the kidney.

PMID: 19896698

Revisiting the immunophenotype of nephrogenic adenoma. Fromont G, Barcat L, Gaudin J, Irani J. Am J Surg Pathol. 2009 Nov;33(11):1654-8. PMID: 19730362

Melanotic Xp11 Translocation Renal Cancer: A Case With PSF-TFE3 Gene Fusion and Up-regulation of Melanogenetic Transcripts. Chang IW, Huang HY, Sung MT. Am J Surg Pathol. 2009 Oct 3. PMID: 19809274

Metastatic Epithelioid Trophoblastic Tumor in a Male Patient With Mixed Germ-cell Tumor of the Testis. Allan RW, Algood CB, Shih IM. Am J Surg Pathol. 2009 Oct 23. PMID: 19898219

Renal Tubulocystic Carcinoma Is Closely Related to Papillary Renal Cell Carcinoma: Implications for Pathologic Classification. Zhou M, Yang XJ, Lopez JI, Shah RB, Hes O, Shen SS, Li R, Yang Y, Lin F, Elson P, Sercia L, Magi-Galluzzi C, Tubbs R. Am J Surg Pathol. 2009 Oct 23. PMID: 19898225

Infiltrating glomus tumor of uncertain malignant potential arising in the kidney.
Gill J, Van Vliet C. Hum Pathol. 2009 Nov 5. PMID: 19896698

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