Xp11.2 translocation carcinoma is a distinct subtype of renal cell carcinoma characterized by translocations involving the TFE3 gene. Our study included the morphological, immunohistochemical and clinicopathological examination of 28 Xp11.2 RCCs. The immunophenotype has been assessed by using CA9, CK7, CD10, AMACR, MelanA, HMB45, Cathepsin K and TFE3 immunostainings. The diagnosis was confirmed by TFE3 break-apart FISH in 25 cases. The ages of 13 male and 15 female patients, without underlying renal disease or having undergone chemotherapy ranged from 8 to 72. The mean size of the tumors was 78.5 mm. Forty-three percent of patients were diagnosed in the pT3/pT4 stage with distant metastasis in 6 cases. Histological appearance was branching-papillary composed of clear cells with voluminous cytoplasm in 13 and variable in 15 cases, including one tumor with anaplastic carcinoma and another with rhabdoid morphology. Three tumors were labeled with CA9, while CK7 was negative in all cases. Diffuse CD10 reaction was observed in 17 tumors and diffuse AMACR positivity was described in 14 tumors. The expression of melanocytic markers and Cathepsin K were seen only in 7 and 6 cases, respectively. TFE3 immunohistochemistry displayed a positive reaction in 26/28 samples. TFE3 rearrangement was detected in all the analyzed cases (25/ 25), including one with the loss of the entire labeled break-point region. The follow-up time ranged from 2 to 300 months, with 7 cancer-related deaths. In summary, Xp11.2 carcinoma is an uncommon form of renal cell carcinoma with a variable histomorphology and rather aggressive clinical course.

The presence of large cells having simultaneously increased cytoplasmic and nuclear volume accompanied by prominent nucleoli; i.e., differentiating neuroblasts and ganglion cells, is well documented in peripheral neuroblastic tumors (pNTs), and considered as one of the signs of tumor maturation and an indication of a better prognosis of the patients. On the other hand, in 2004 it was reported that large-cell neuroblastoma composed of neuroblastic cells with only nuclear enlargement without recognizable cytoplasmic maturation behaved poorly clinically. Here we are proposing a new pNT subtype in the neuroblastoma category, in addition to the undifferentiated, poorly differentiated and differentiating subtypes: that is large nucleolar neuroblastoma (LNN) characterized by large prominent nucleoli and no or very little amount of discernible cytoplasm. LNN, whose neuroblastic cells are often large in size due to nuclear enlargement, includes those tumors previously categorized into the large-cell neuroblastoma group. LNN tumors, regardless of the size of nuclei, seem to behave aggressively with a very poor prognosis of the patients. It is speculated that nucleolar enlargement without cytoplasmic maturation in LNN tumor cells can be a sign of MYCN amplification.

Numerous studies investigated the localization of pituitary adenylate cyclase-activating polypeptide (PACAP) and its receptors in different tumors and described the effects of analogs on tumor growth to show its potential role in oncogenesis. Recently, our research group has found significantly lower levels of PACAP27-like immunorreactivity (LI) and PACAP38-LI in different human samples of primary small cell lung cancer and colon cancer compared to normal healthy tissues. There are only few human studies showing the presence of PACAP and its receptors in urogenital tumors; therefore, the aim of the present study was to compare PACAP-LI in different healthy and pathological human samples from urogenital organs (kidney, urinary bladder, prostate, testis) with radioimmunoassay (RIA) method. Similar to our earlier observations, the PACAP27-LI was significantly lower compared to PACAP38-LI in all samples. We did not find significant alterations in PACAP-LI between healthy and tumoral samples from the urinary bladder and testis. On the other hand, we found significantly lower PACAP38-LI level in kidney tumors compared with healthy tissue samples, and we showed higher PACAP27-LI in prostatic cancer compared to samples from benign prostatic hyperplasia. These data indicate that PACAP levels of different tissue samples are altered under pathological conditions suggesting a potential role of PACAP in the development of different urogenital tumors.

There are no adequate immunohistochemical markers for papillary renal cell tumours. The aim of this study was to establish a gene expression profile of papillary renal cell tumours using an expression microarray approach. Through hierarchical clustering and significant analysis of microarrays, we have selected the best 13 genes and analysed their expression by real-time polymerase chain reaction (RT-PCR). Of these genes, we selected SCEL as potential marker of interest. Immunohistochemical staining of tissue microarrays containing all major types of kidney cancers revealed positive staining for sciellin in 87 of 114 papillary renal cell tumours and in 13 of 19 precursor lesions. No other renal tumour types were positive for sciellin. Our study indicates that although not all tumours express sciellin, its expression may help to confirm the diagnosis papillary renal cell tumour.

Extraintestinal manifestations of Crohn's disease (CD) are varied and concentrated mainly to the skin and eye. Urinary tract or renal involvement is extremely rare. Herein we report on a case of renal lesion of a 50-year-old woman with a 15-year history of CD. Abdominal computed tomography scan of the patient identified heterogeneous multinodular mass lesions in the left kidney. Histology proved classic granulomatous inflammatory nodules with multinucleated giant cells, eosinophils, plasma cells, epithelioid cells, and spindle-shaped myofibroblasts in the areas, where the computed tomography scan indicated. After the extensive PubMed search in the literature, this is the first macroscopically documented and histologically proved, mass-like renal involvement in CD. From now on, differential diagnostics of renal mass lesions in CD should include the tumor-like, Crohn's-type granulomatous inflammation as direct kidney manifestation of the disease.