1/4. Metanephric adenofibroma: report of a case and review of the literature.The recent recognition of a variety of pediatric renal tumors of different biologic behavior places an ever-increasing demand on the surgical pathologist for an accurate diagnosis. Although metanephric adenofibroma is one of the rarest benign renal tumors, the clinical importance of correctly diagnosing it cannot be overemphasized because it can potentially be mistaken as Wilms' tumor. We describe the clinical, radiologic, and pathologic features of a case of metanephric adenofibroma and discuss its differential diagnosis. The neoplasm was composed of two discrete components: a major fibroblastic element and a minor immature epithelial element. The latter formed a small nodule beneath the renal capsule, which could barely be detected by magnetic resonance imaging. This subcapsular nodule, however, was slightly soft and tan and was distinctly different from the white, whorled cut surface of the main tumor. It was formed by closely packed small immature epithelial cells in a slightly edematous background, which was histologically identical to metanephric adenoma and closely resembled epithelial Wilms' tumor. Unlike Wilms' tumor, however, the epithelial cells were very bland with no mitoses. The main bulk of the tumor was formed by spindle fibroblastic cells that were cytologically similar to the spindle cells in congenital mesoblastic nephroma. The tumor, however, was well demarcated without the irregular infiltrating edges of congenital mesoblastic nephroma. In contrast to the randomly distributed epithelial element throughout the stromal component in previous reported cases of metanephric adenofibroma, our finding of the exceedingly small and discrete epithelial component expands the known histologic spectrum of the disease. In addition, the presence of such minute epithelial nodule underscores the importance of diligent pathologic examination and careful sampling of tissue for histologic examination.- - - - - - - - - - ranking = 1keywords = adenofibroma (Clic here for more details about this article) |
2/4. Nephrogenic adenofibroma in a young child.Nephrogenic adenofibroma is a benign renal tumor in children and young adults described by Hennigar and Beckwith in 1992. Seven cases have been described, and we report the first case in an 11-month-old child, in good health, revealed by a macroscopic hematuria. Nephrogenic adenofibroma is an unusual tumor, which was difficult to distinguish from nephroblastoma and mesoblastic nephroma. Beckwith makes a distinction between this principal differential diagnosis in child renal tumors based upon morphologic and immunohistochemical patterns. In our observation, the diagnosis remained difficult and needed several reviews of our case. Beckwith proposed the final diagnosis: nephrogenic adenofibroma with stromal predominance. The prognosis is excellent and no treatment is indicated. A FISH analysis of the tumor cells found a trisomy 11. trisomy 11 has been reported in mesoblastic nephroma as the most frequent chromosomal abnormality. This finding in tumor cells provides an argument for excluding the diagnosis of nephroblastoma but can not clarify the difference between nephrogenic adenofibroma and mesoblastic nephroma.- - - - - - - - - - ranking = 1.1428571428571keywords = adenofibroma (Clic here for more details about this article) |
3/4. adenomyoma: a precursor of extrauterine Mullerian adenosarcoma?One patient had an extrauterine pelvic Mullerian adenosarcoma that recurred on multiple occasions and was originally diagnosed as a benign lesion. Caution is needed in the initial interpretatrion of such lesions as "adenofibromas." We have compared this lesion with a benign adenomyoma of the uterus from a second patient and suggest that such benign neoplasms serve as precursors for Mullerian adenosarcoma in some cases. light and electron microscopic observations in the first case as well as data from the literature support this hypothesis.- - - - - - - - - - ranking = 0.14285714285714keywords = adenofibroma (Clic here for more details about this article) |
4/4. Benign mixed epithelial and stromal tumor of the kidney.We describe a distinctive benign tumor of the kidney in a 48-year-old woman, which was composed of well differentiated ducts set in the spindle cell stroma which was muscle actin, smooth muscle actin and desmin positive, and was morphologically similar to the ovarian stroma. No immature appearing epithelial renal or mesenchymal tissue was present in the tumor. Histologically, the tumor differed from the nephrogenic adenofibroma and the rare cases of adult Wilms tumors, mesoblastic nephromas and cystic nephromas.- - - - - - - - - - ranking = 0.14285714285714keywords = adenofibroma (Clic here for more details about this article) |