Objective: Leydig cell tumor is a rare form of testicular neoplasm, representing only 1-3 % of all testicular tumors. According to accepted medical knowledge, this type of tumor isn't linked to cryptorchidism, unlike germ cell tumors of the testicles. Herein, a case of Leydig cell tumor in a cryptorchid testis is described. Method: A 59-year-old, unmarried man was admitted for surgical repair of inguinal hernia. His past medical history included untreated bilateral cryptorchidism first noted in childhood, as well as poliomyelitis that presented at age two. The past surgical history and review of systems were noncontributory. A CT scan of the abdomen and pelvis revealed two 3×3 cm testicles at the level of the inguinal canal. He underwent bilateral inguinal orchiectomy combined with surgical repair of his inguinal hernia. Results: The right testis contained a solid, well-circumscribed, round, tan-colored tumor 1.5 cm in diameter. The histological appearance was that of a Leydig cell tumor exhibiting no mitotic figure. There was no clinical or radiological evidence of metastatic spread. Conclusion: Although cryptorchidism is considered to be a risk factor for developing germ cell tumors, there have been a few reported cases of Leydig cell tumors with a history of cryptorchidism. Our case adds to the evidence that there may be a link between the two conditions. Objective: CD44, E-cadherin, β-catenin are "cell adhesion molecules" and appear to influence development, inflammation, cancer invasion and metastasis. We studied the expression of these CAMs in prostatic adenocarcinoma (PCa), high grade prostatic intraepithelial neoplasia (HGPIN) and nodular adenomatous hyperplasia (NH). Method: 135 specimens of radical prostatectomies were assessed. These CAMs were determined by immunohistochemistry. All sections included PCa, HGPIN, and NH. The expression of these markers was evaluated with three scores. The correlation of immunopositivity with Gleason score and TNM stage was investigated. Results: CD44 was strongly expressed in 41.5 %, 46.7 % and 37.8 % of NH, HGPIN and PCa, respectively. E-cadherin immunostaining was higly detected in 71.1 %, 78.5 % and 63.0 % of NH, HGPIN and PCa areas while β-catenin immunostaining was exclusively membranous in 80.7 % of NH and nuclear/cytoplasmic in 70.4 % and 48.9 % of HGPIN and PCa areas. All markers were unrelated to Gleason score (p=0.352). CD44 and E-cadherin immunopositivities were inversely associated with TNM stage (p=0.021 and p=0.042 respectively); such an association was not observed in β-catenin (p=0.556). Conclusion: CD44 and E-cadherin decreased expression is probably associated with invasive potential of prostate cancer. β-catenin staining pattern in neoplastic lesions differs from that in non-neoplastic prostate lesions. Results: The loss of ECAD expression was significantly higher at the TIF when comparing with TSCP and NNM. The loss of ECAD was correlated with histological grade, infiltrative pattern, lymph node metastasis, perineural and vascular invasion. The vimentin expression showed association with histological grade, infiltrative pattern, T stage, lymph node metastasis, perineural and vascular invasion. Conclusion: The loss of ECAD and the gain of vimentin expressions occur more frequently at the tumor invasion front and are associated with classic factors of poor prognosis and low survival rates.