Chromophobe renal cell carcinoma with microcystic and adenomatous arrangement and pigmentation--a diagnostic pitfall. Morphological, immunohistochemical, ultrastructural and molecular genetic report of 20 cases.

We present clinical, morphological, immunohistochemical, ultrastructural and molecular genetic features of 20 cases of a peculiar form of chromophobe renal cell carcinoma (CRCC) with morphology differing from that of conventional CRCC. Microscopically, the typical features of the tumors were microcystic arrangement and formation of adenomatous structures. Microcystic areas were composed of smaller eosinophilic and bigger pale cells having cytological appearance typical of conventional CRCC. Cytological features of the adenomatous structures were mostly different from those of conventional CRCC. They had a typical columnar arrangement with nuclei positioned at the base of the glandular structures and a small amount of a deeply eosinophilic cytoplasm often endowed with brush border facing the lumen of the glands. In addition, all the tumors showed a brown pigmentation. The pigmentation was located mostly extracellularly, where it formed pools of heavy deposits. Microscopic calcifications present in all cases formed psammoma bodies or else the calcifications were more extensive and amorphous in shape. Ultrastructurally, the cells showed features characteristic of CRCC: typical cytoplasmic vesicles were 100-700 nm in size and mitochondria had tubulovesicular, lamellar or circular cristae. Some tumor cells contained dark, variously sized electron-dense pigment granules. Neither melanosomes nor membrane-bound neurosecretory granules were seen. Using fluorescence in-situ hybridization probes for chromosomes 1, 2, 6, 10, 13, 17 and 21, the tumors revealed massive loss of tested chromosomes typical for conventional CRCC. Monosomy of chromosomes 1, 2, 6, 10, 13 and 21 was found in 100, 36, 91, 82, 82, 82 and 64% of cases, respectively. None of the cases showed mutation of exons 9, 11, 13 and 17 of the c-kit gene. The important feature of pigmented microcystic chromophobe renal cell carcinoma is a relatively benign biological behavior and the absence of distant metastases and sarcomatoid transformation.

[Spindle cell and cuboidal renal cell carcinoma (loopoma). 10 case reports]. / Vretenobunecný a kuboidální renální karcinom (loopom). Popis 13 prípadu.

BACKGROUND: Current classification systems of neoplasms arising from renal parenchyma distinguish 5 categories of renal cell carcinoma (RCC), i.e. conventional RCC, papillary RCC, chromophobe RCC, collecting duct/medullary RCC and unclassified RCC. We present 13 cases of unusual and unclassified spindle and cuboidal renal cell carcinomas. METHODS AND RESULTS: The studied group consisted of 13 patients (7 men and 6 women). They ranged in age from 22 to 65 years (mean 57.3). Generally, the tumours were well circumscribed and confined to the kidney, whitish to grey on section with a diameter 4.5-13 cm (mean 8.6 cm). One patient was investigated for loin pain and nocturia. Three patients had staghorn nephrolithiasis and vague sonographic findings in renal parenchyma. In one patient the renal tumour was found when examined on follow-up examination for prostatic adenocarcinoma. None of our patients was known to have elevated levels of parathyroid hormone due to hyperplasia, adenoma or carcinoma of the parathyroid gland. Clinical follow-up of the patients ranged from 9 months to 8 years (mean 2.3 years). Microscopically, the tumours were composed of two main populations of cells: flattened, spindle cells with sparse cytoplasm and small cuboidal cells with clear to light eosinophilic cytoplasm. Eight patients are currently well without signs of recurrence or metastasis, one had metastasis in the regional lymph node at the time of nephrectomy, one died of unrelated cause, and three were lost to follow-up. CONCLUSIONS: We present 13 cases of unclassified RCC. Our cases were histologically, immunohistochemically and ultrastructurally similar to the hitherto reported case reports of this variant of RCC. It is obvious, that that variant of RCC should be recognised as a new subtype of RCC.

Spindle and cuboidal renal cell carcinoma, a tumour having frequent association with nephrolithiasis: report of 11 cases including a case with hybrid conventional renal cell carcinoma/ spindle and cuboidal renal cell carcinoma components.

AIMS: We present the largest series of an unclassified subtype of renal cell carcinoma, which seems to be a distinct morphological entity and which is sometimes designated as spindle and cuboidal renal cell carcinoma. METHODS AND RESULTS: Eleven cases of spindle and cuboidal renal cell carcinoma were found among 7000 primary renal cell tumours in Pilsen's routine and consultation files. The patients were five men and six women. They ranged in age from 22 to 65 years (mean 56.8). Microscopically, the tumours were composed of two main populations of cells. First, the preponderant type of cells was formed by flattened, spindle cells with sparse cytoplasm. The second cell type was a small cuboidal cell with clear to light eosinophilic cytoplasm. Spindle-shaped cells were arranged in a fascicular pattern often reminiscent of low-grade smooth muscle tumours. Solid areas of spindle cells were also present. Small cuboidal cells formed sparse tubular structures lined by a row of single cells. In addition to all previous published cases of spindle and cuboidal renal cell carcinoma we observed an association of nephrolithiasis in our cases. It was seen in 3/11 of our patients. A previously unreported feature is the occurrence of a conventional renal cell carcinoma component in one of our cases. Seven of our patients are currently well without signs of recurrence or metastasis, one had metastasis in a regional lymph node at the time of nephrectomy, one died of an unrelated condition, and two were lost to follow-up. CONCLUSIONS: We present 11 cases of spindle and cuboidal renal cell carcinoma, which is believed to be a distinctive morphological entity. Our cases were histologically, immunohistochemically and ultrastructurally similar to the previously reported cases of spindle and cuboidal renal cell carcinoma. In contrast to all previously reported cases of spindle and cuboidal renal cell carcinoma, we observed an association with nephrolithiasis in three of our cases; moreover, one of our tumours had a conventional renal cell carcinoma component and another revealed a metastatic focus in a regional lymph node. None of our patients died of the disease. This study confirms that spindle and cuboidal renal cell carcinoma has a low malignant potential.

[Metanephric adenoma. 11 case reports and detection of collagen spherules in one tumor]. / Metanefrický adenom. Popis 11 prípadu s prukazem kolagenních sferul v jednom nádoru.

Eleven cases of metanephric adenoma are reported. The tumors were selected out of 6500 tumorous and pseudotumorous lesions of the kidney in our registry. Female to male ratio was 1:1.2. The average age of the patients was 48.3 years, with a range of 13-79 years. The mean size of the tumors was 7.2 cm. The tumors were spherical in shape, whitish to yellowish in colour. Histologically, they were arranged in a mainly tubular pattern with short pseudopapillae. The tumorous cells were deeply eosinophilic to basophilic with predominantly round nuclei. Psammomatous bodies were numerous. Immunohistochemically, they reacted positively with antibodies against cytokeratins, vimentin, and WT1. Ultrastructurally, the cytoplasm contained mitochondria, RER, and ribosomes. A collagenous spherulosis, identical with those in salivary gland and mammary tumors, was revealed in one case. The spherules were located mainly inside tubular structures. Ultrastructurally, they were composed of basement membrane-like material, which was surrounded by epithelial cells. Follow-up all of our patients was negative (if known) for 10 months to 4 years.