Neurofibroma of kidney: An uncommon neoplasm and diagnostic dilemma with solitary fibrous tumor
ABSTRACT Neurofibroma of kidney is an extremely rare tumor. To our knowledge, only five such cases have been reported worldwide till date. Here, we report a solitary neurofibroma of right kidney in a 54-year-old woman. Radiological investigations (ultrasonography and computed tomography) detected a solid mass in the upper pole of right kidney and clinicoradiologically renal cell carcinoma was suspected. A radical nephrectomy was performed under diagnosis of cancer. Microscopically, tumor consisted of benign spindle-shaped cells accompanied by fibrous tissue. Differential diagnoses of neurofibroma and solitary fibrous tumor (SFT) were made on morphological features. Immunohistochemically, the tumor cells were positive for S-100 protein, but negative for CD34 and CD99. Thus, a diagnosis of neurofibroma was established.
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ABSTRACT: Metanephric stromal tumor (MST) is a rare pediatric neoplasm unique to the kidneys that is currently included in the spectrum of metanephric tumors, along with metanephric adenoma and adenofibroma. We herein report an unusual case of pediatric renal stromal tumor overlapping with MST and solitary fibrous tumor (SFT). Histologically, the tumor was composed of bland-looking spindle to stellate cells embedded in a fibro-sclerotic stroma that focally surrounded native entrapped renal tubules or blood vessels with abortive rings or collarettes. Alternating hypercellular and hypocellular areas and a focal hemangiopericytomatous-like vascular pattern imparted to the tumor a resemblance to SFT. Angiodysplasia of intratumoral arterioles was also observed, but juxtaglomerular cell hyperplasia was not a feature. Immunohistochemically, the neoplastic cells showed a polyphenotypic profile, including diffuse expression of vimentin and CD34, and focal immunoreactivity for alpha-smooth muscle actin, EMA, and CD99. However, the most striking finding was diffuse nuclear and cytoplasmic expression of S-100 protein. Although this protein has been reported to stain the heterologous glial and/or cartilaginous components that can be occasionally encountered in MST, this marker has not been previously reported in the fibroblastic component of MST. Pathologist should be aware of similar unusual unclassified tumors to avoid potential confusion with other benign or malignant S-100 protein-positive tumors.Pathology - Research and Practice 09/2011; 207(11):707-11. DOI:10.1016/j.prp.2011.07.008
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ABSTRACT: The neurofibroma is a tumour of neural origin. This kind of neoplasm, though, is generally skin located. Rare cases in deep organs or in the peritoneal cavity are also reported in the literature. There are two types of neurofibromas, localized and diffuse; the latter is associated with von Recklinghausen disease and always occurs together with skin neurofibromas. Here we report the case of a 47-year-old man affected by retroperitoneal neurofibroma, but not associated with von Recklinghausen disease. A computed tomography (CT) scan described a retroperitoneal pararenal lesion with no clear involvement of adjacent viscera. We describe the diagnostic modality, treatment planning and the timing of treatment of this neoplasm, reviewing also the literature.ecancermedicalscience 05/2012; 6:253. DOI:10.3332/ecancer.2012.253