Objective: Radical cystoprostatectomy is a standard surgical procedure for male patients with muscle-invasive urinary bladder (UB) carcinoma. Vast majority of these tumors are urothelial carcinomas, while large cell neuroendocrine carcinoma (LCNEC) is a very uncommon tumor with less than 20 reported cases. Invasive prostate carcinoma is incidentally detected in up to 20 % of cystoprostatectomy specimens. It is usually well differentiated and shows low propensity for dissemination and local recurrence. Method: Clinical and pathological description of an extremely rare collision tumor composed of LCNEC of the urinary bladder and a high grade acinar prostate carcinoma. Results: A 79-year-old male patient was admitted to the urology department due to severe gross haematuria. Cystoscopy revealed large tumor of the posteriorinferior wall of the UB with involvement of the left uretheral orifice. In the radical cystoprostatectomy specimen LCNEC of the UB, involving bilaterally prostate and spermatic vesicle (pT4a), was diagnosed. Additionally both lobes of the prostate were involved by the acinar prostatic carcinoma (pT2c, Gleason score 5+4=9). Conclusion: High-grade prostate carcinoma may rarely coexist with UB tumors of uncommon histology. Objective: Despite of numerous researches in the field, data regarding immunohistochemical (IHC) expression of androgen receptor (AR) in prostate carcinomas, in terms of prognosis and therapy, are quite controversial. Method: The IHC expression of AR was analyzed on 3 groups, each of 20 primary diagnosed prostate carcinomas: localized, locally advanced and distant metastasized. The anti-AR antibody (clone AR441) was used. For each tumor was determined the percentage of AR-positive nuclei, assigning a staining score (0 to 4). A value of 64 % was considered to be discriminat o r y b e t w e e n t u m o r s w i t h h i g h a n d l o w A R expression. Results: All the analyzed carcinomas showed AR. 54.2 % of tumors had high AR expression and 45.8 % showed low AR expression. 7/19 localized tumors (one tumor vanished during processing), 15/20 locally advanced and 10/20 distant metastasized tumors showed high AR expression (p=0.051). 5/18 well-differentiated, 16 of 23 moderately differentiated and 11/18 poorly differentiated tumors showed high expression of AR (p=0.022). Conclusion: Although not reaching statistical significance, the AR expression tended to correlate with the stage of disease and with the degree of differentiation in terms of an increased expression of AR in advanced, moderately and poorly differentiated tumors. Objective: Prostate lesions with atypical stromal component are rare and poorly characterized in terms of evolution and prognosis. Method: We retrospectively analyzed 3 cases of unusual prostate tumors diagnosed on prostate needle biopsy. The biopsies were performed due to an elevated serum PSA and/ or phenomena of bladder outlet obstruction. For the immunohistochemical (IHC) diagnosis there were used the following antibodies: CK AE1/AE3, PSA, PSMA, vimentin, SMA, ER, Desmin, PgR, CD34. Results: Two of the three patients, one 68 and the other 66 years-old, with serum PSA level of 34 ng/ml and 14.58 ng/ml respectively, were diagnosed with sarcomatoid carcinoma, the former presenting with liver metastases at diagnosis. In evolution, the death of the first patient occurred 3 months after the diagnosis and the second patient refused surgery. The third patient, 75 years-old, with a nodular prostatic mass of 3.3 cm, was clinically suspected to have an unusual malignant prostatic tumor considering that, despite his 7 ng/ml of serum PSA, he presented multiple bone metastases. The histopathological diagnosis was Stromal Tumor of Uncertain Malignant Potential. Conclusion: The prostate lesions with atypical mesenchymal component are rarities in urologic pathology. An accurate diagnosis relies on meticulous pathological examination techniques and supplemented, for rare cases, with other clinical and laboratory data.