Hidradenocarcinoma of the Scrotum.

Lesions of the skin and soft tissues of the penis and scrotum may be confusing in urological practice, since rare differential diagnoses can be challenging to providers with limited dermatological experience. Hidradenocarcinoma is one of such diagnoses, a rare and aggressive malignant tumor originating from sweat glands. A 61 year-old man presented with a nodule in the penoscrotal region which had appeared 1 year before consultation. He had no history of penile lesions, sexually transmitted diseases, or other complaints. Surgical resection revealed a hidradenocarcinoma of the scrotum infiltrating subcutaneous tissue.

Spectrum of abdominal imaging findings in histiocytic disorders.

OBJECTIVES: The present article provides an overview of the spectrum of abdominal findings of histiocytic disorders that may be observed in multimodality imaging illustrated by clinical cases from our Imaging Center. METHODS: We will review abdominal findings of Langerhans cell histiocytosis, Rosai-Dorfman disease, Erdheim-Chester disease, and hemophagocytic syndrome illustrated by clinical cases from our imaging department with histologic correlation. RESULTS: Abdominal involvement of histiocytic disorders is rare and may occur in the liver, biliary tract, kidney, retroperitoneum, kidney, gastrointestinal tract, and lymph nodes. CONCLUSION: Histiocytic disorders encompass a group of rare diseases with a wide range of manifestations in which the abdominal involvement is quite infrequent. The role of the radiologist is to report the major imaging findings and the differential diagnosis; however, the imaging features are unspecific and biopsy usually is necessary to establish the definitive diagnosis.

Evaluation and comparison of microvessel density using the markers CD34 and CD105 in regenerative nodules, dysplastic nodules and hepatocellular carcinoma.

PURPOSE: The progression of hepatocellular carcinoma (HCC) is multifactorial and angiogenesis plays a fundamental role, mainly because HCC is a highly vascularized tumor. METHODS: In this study, we determined microvessel density (MVD) using the immunohistochemical markers, CD34 and CD105 (Endoglin), in 44 hepatectomy specimens, encompassing 44 malignant nodules (HCC), 44 regenerative nodules (RN), and 15 dysplastic nodules (DN). The evaluation included the determination of MVD in all nodules. For statistical analysis, a descriptive analysis was carried out using measurements of position and dispersion for continuous variables; ANOVA was used to compare between groups, considering p < 0.05 as statistically significant. RESULTS: We observed a significant difference when comparing CD34 and CD105 immunoexpression in HCC, DN, and RN. CD105 was predominantly expressed in the peripheral regions in HCC, with mean MVD scores of 6.2 ± 4.1 and 10.7 ± 4.4 at the center and periphery of the nodules, respectively, with significant differences between groups (p < 0.0001). CD34 had higher mean MVD scores than CD105 in HCC, with a more uniform positivity pattern. CD105 immunoexpression in DN exhibited a pattern similar to HCC. However, in RN, CD105 exhibited a higher MVD score in the central portion of the nodules. CD105 was expressed in a subset of newly formed microvessels in HCC and demonstrated an elevated mean MVD in cirrhotic or regenerative nodules. CONCLUSIONS: MVD determined by CD34 and CD105 expression may be used as an additional parameter to distinguish benign from malignant liver nodules.

Leydig cell tumor of the testis with histological and immunohistochemical features of malignancy in a 1-year-old boy with isosexual pseudoprecocity.

The article reports the clinical, histopathological, and immunohistochemical findings of a 1-year-old boy presenting with isosexual pseudoprecocity attributable to a functioning Leydig cell tumor of the testis. The case appears to represent the youngest patient ever recognized with this well-known syndrome. Malignancy features were also for the first time initially assessed using criteria, retrospectively developed from the literature, for metastasizing Leydig cell tumor. All the following were found: infiltrative borders, cellular pleomorphism, high mitotic index (12-14/high-power field), high MIB-1 index (40%), P53 positivity in 50% of the cells, and bcl-2 positivity in 15% of the cells. Immunohistochemistry proved the cells of the tumor to be positive for inhibin, Melan-A, synaptophysin, cytokeratin, and calretinin and negative for S-100 and chromogranin A. Notably, lipochrome and crystals of Reinke were not found in the tumor cells. Although the neoplasm fulfilled the criteria for a potentially metastasizing Leydig cell tumor, there was no evidence of that event having occurred, perhaps as a result of early treatment or as indication that criteria developed for Leydig cell tumor of adults may not apply to children.