Yeh I, Argenyi Z, Vemula SS, et al. Plexiform melanocytic schwannoma: a mimic of melanoma
ABSTRACT We present a unique dermal tumor for which we propose the term plexiform melanocytic schwanomma. The proliferation consisted of lobules of epithelioid and spindled cells with S100, Melan-A and HMB-45 positivity but without obvious melanin pigmentation. The nuclei were moderately pleomorphic in some areas, and in a few areas the mitotic index was elevated. Schwannian differentiation was inferred from the presence of areas with nuclear palisading resembling Verocay bodies, from plexiform architecture and from the presence of a thin rim of EMA positivity around the tumor. Array-based comparative genomic hybridization showed genomic losses that overlap with those seen in sporadic schwanomma. The differential diagnosis included melanoma, melanotic schwannoma and cutaneous melanocytoneuroma, and we compare and contrast our case with these entities.
Yeh I, Argenyi Z, Vemula SS, Furmanczyk PS, Bouffard D, McCalmont TH. Plexiform melanocytic schwannoma: a mimic of melanoma.
Article: The cure for boredomJournal of Cutaneous Pathology 04/2012; 39(4):404-5. DOI:10.1111/j.1600-0560.2012.01897.x · 1.56 Impact Factor
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ABSTRACT: : The term neurotropic melanoma has been used to refer to malignant melanoma with associated infiltration of nerve or "neural differentiation"-that is, melanoma cells exhibiting cytological characteristics of nerve cells. Historically, neurotropic melanoma has generally been discussed within the context of desmoplastic melanoma. We report an exceptional case of melanoma notable for a very well-differentiated neural component that was contiguous with obvious overlying melanoma. After careful consideration of all pertinent histological features, the overall diagnostic impression was that of melanoma with associated "malignant neurotization." We have not encountered a previously reported case with such a well-differentiated neural component. The following article details our exceptional case of melanoma with "malignant neurotization" and presents a discussion of the differential diagnosis and brief review of the pertinent literature.The American Journal of dermatopathology 06/2013; 36(1). DOI:10.1097/DAD.0b013e31828cf90a · 1.43 Impact Factor
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ABSTRACT: Melanotic schwannoma (MS) is an unusual variant of nerve sheath neoplasm. Only 10% of these tumors will undergo malignant degeneration, with exceedingly rare reported metastasis. We present a 32-year-old woman with a 6-month history of cervical pain and left arm progressive weakness. Neurological examination showed a left upper limb radicular pain, with pyramidal syndrome at C5 level. The magnetic resonance imaging (MRI) study highlighted an intradural extramedullary heterogeneous mass along the spinal cord at the C4-C5 level, slightly hyperintense with T1 and hypointense with T2-weighted sequences, invading the left neural foramen. The patient underwent C3-C5 laminectomy with total resection of a black tumor. In the postoperative period, a patent deficit of shoulder abduction ensued related to the nervous section. Microscopically, compactly fascicles of spindle-shaped cells with pleomorphic and hypercromatic nuclei, dark brown intracellular pigments, as well as some mitotic figures were seen. Immunohistochemical stains for S-100, Human Melanoma Black-45 (HMB-45), and vimentin were positive, with Ki-67 Labelling Index (LI) of 15% compatible with MS. Six months after radiotherapy she presents local recurrence and lung metastatic dissemination of the MS. She underwent left pulmonary segmentectomy, followed by chemotherapy and radiosurgery. The patient developed a febrile neutropenia and worsening of general status, and died after 3 months due to respiratory complications. MS are rare tumors with potential for local recurrence and distal metastasis. Complete surgical resection remains as the treatment of choice, once the uncommon cases with malignant progression shows low response to chemo and radiotherapy.Neurologia medico-chirurgica 09/2013; 53(10). DOI:10.2176/nmc.cr2012-0203 · 0.65 Impact Factor