Amin MB, MacLennan GT, Gupta R, et al..Tubulocystic carcinoma of the kidney; clinicopathologic analysis of 31 cases of a distinctive rare subtype of renal cell carcinoma

Department of Pathology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA.
The American journal of surgical pathology (Impact Factor: 5.15). 12/2008; 33(3):384-92. DOI: 10.1097/PAS.0b013e3181872d3f
Source: PubMed


A distinctive tumor described under the terms Bellini duct carcinoma and low-grade collecting duct carcinoma has been referred to by us and others as tubulocystic carcinoma. This renal cell carcinoma subtype is not recognized in the World Health Organization 2004 classification. Herein, we present a detailed study of 31 cases to further characterize this rare subtype of renal cell carcinoma. The tumor occurred in adults (mean age, 54 years) with a strong male predominance (7:1). Grossly, the tumors ranged from 0.7 to 17 cm, and exhibited a spongy or "bubble wrap" appearance reflecting the microscopic presence of variably sized cystically dilated tubules lined by a single layer of epithelium. The lining varied with a cuboidal, flat, and hobnail cell appearance, and the neoplastic cells had abundant eosinophilic cytoplasm and enlarged nuclei with prominent nucleoli. The cysts were closely spaced with an intervening variably fibrotic stroma. Immunohistochemistry and ultrastructural examination showed features of proximal convoluted tubules (Pax 2 immunoreactivity and short microvilli with brush border organization) and distal nephron (kidney-specific cadherin immunoreactivity and cytoplasmic interdigitation). Gene expression profiling showed that tubulocystic carcinoma displayed a unique molecular signature. Twenty-four tumors were stage pT1, 4 stage pT2, and 3 stage pT3. Disease progression (median follow-up of 56 months) occurred in 3 patients; 1 with local recurrence, and 2 with distant metastasis to bone and liver. In light of the distinctive clinicopathologic features and a low but definite metastatic potential, this unique subtype of renal cell carcinoma deserves formal recognition in the contemporary classification of renal neoplasms.

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    • "Tubulocystic renal carcinoma (TCRC) is a rare tumor, and has been recently recognized as a neoplastic entity. TCRC was not formally described in the World Health Organization 2004 classification or the guidelines given in the 2004 Armed Forces Institute of Pathology fascicle [1,2]; however, Amin et al. were the first to report about TCRC on the basis of its characteristic morphology [3]. Here we report a case of TCRC in the left kidney and present a review of the relevant literature. "
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    ABSTRACT: Introduction Tubulocystic renal carcinoma is a rare tumor and has been recently recognized as a neoplastic entity. We report a case of tubulocystic renal carcinoma in the left kidney and present a review of relevant literature. Case presentation A 35-year-old Japanese woman visited our hospital with the chief complaint of left-sided back pain. Computed tomography revealed a hemorrhagic cyst (size, 7×8cm) in the upper pole of her left kidney. Approximately 3 years after the initial diagnosis, she complained of left-sided back pain again. Magnetic resonance imaging revealed an enlarged left renal cyst (size, 10×12cm) with a slightly enhanced cystic wall. The tumor was clinically diagnosed as a renal cell carcinoma in the cT2N0M0 stage, which arose from the cyst wall; therefore, left nephrectomy was performed. On histological examination, the tumor showed circumscribed proliferation with cystically dilated tubules. The tubules and cysts were lined by a single layer of flat, hobnail, and cuboidal cells. Immunohistochemical analysis revealed that the tumor cells were strongly positive for E-cadherin and P504S. Conclusions Examination of more cases of tubulocystic renal carcinoma is required to better understand the biology of this tumor and to ascertain its prognosis.
    Full-text · Article · Jul 2014 · Journal of Medical Case Reports
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    • "Clinically, TCRCs occur predominantly in men with a wide age range and a mean of 54 years [2]. They are less aggressive than other renal carcinomas. "
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    ABSTRACT: Tubulocystic renal carcinoma is a recently described neoplasm of low grade malignancy which was not included in the last WHO 2004 classification. The tumor is extremely rare with less than one hundred cases reported to date. In this article, the literature about that rare renal neoplasm is reviewed and an additional case is reported.
    Full-text · Article · Mar 2013 · African Journal of Urology
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    • "TCRC is a rare entity that characteristically has a small size at presentation (mean 2 cm) and rarely progresses, recurs, or metastasizes [7,8,12,13]. It has been reported in association with other RCCs, primarily papillary RCC [5]. Recent immunohistochemical, ultrastuctural, and molecular studies (RNA expression levels and genomic profile analyses) have shown that TCRC is different from collecting duct carcinoma and may be related to papillary RCCs [5,7,8,13-15]. "
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    ABSTRACT: Seven percent of renal cell carcinoma (RCC) cases are diagnosed as "unclassified" RCC by morphology. Genetic profiling of RCCs helps define renal tumor subtypes, especially in cases where morphologic diagnosis is inconclusive. This report describes a patient with synchronous clear cell RCC (ccRCC) and a tubulocystic renal carcinoma (TCRC) in the same kidney, and discusses the pathologic features and genetic profile of both tumors. A 67 year-old male underwent CT scans for an unrelated medical event. Two incidental renal lesions were found and ultimately removed by radical nephrectomy. The smaller lesion had multiple small cystic spaces lined by hobnail cells with high nuclear grade separated by fibrous stroma. This morphology and the expression of proximal (CD10, AMACR) and distal tubule cell (CK19) markers by immunohistochemistry supported the diagnosis of TCRC. The larger lesion was a typical ccRCC, with Fuhrman's nuclear grade 3 and confined to the kidney. Molecular characterization of both neoplasms using virtual karyotyping was performed to assess relatedness of these tumors. Low grade areas (Fuhrman grade 2) of the ccRCC showed loss of 3p and gains in chromosomes 5 and 7, whereas oncocytic areas displayed additional gain of 2p and loss of 10q; the high grade areas (Fuhrman grade 3) showed several additional imbalances. In contrast, the TCRC demonstrated a distinct profile with gains of chromosomes 8 and 17 and loss of 9. In conclusion, ccRCC and TCRC show distinct genomic copy number profiles and chromosomal imbalances in TCRC might be implicated in the pathogenesis of this tumor. Second, the presence of a ccRCC with varying degrees of differentiation exemplifies the sequence of chromosomal imbalances acquired during tumor progression. Virtual Slides The virtual slide(s) for this article can be found here:
    Full-text · Article · Feb 2012 · Diagnostic Pathology
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