Mucosal melanomas are rare, and less is known about the biomarkers of this subtype in comparison to cutaneous or uveal melanomas. Preferentially expressed antigen in melanoma (PRAME) has been studied as a tool for prognostication of uveal melanomas, and immunotherapy against PRAME-expressing tumor cells has already shown promise. Our goal was to retrospectively analyze 29 cases of mucosal melanomas at our institution to determine if any molecular and histopathologic prognosticators could be identified, as well as to study PRAME expression and its association with prognosis. We found that the majority of mucosal melanomas expressed PRAME and a high PRAME expression score predicted a poor prognosis. There was no association between prognosis and the histomorphologic features analyzed, such as presence of spindle cell or epithelioid predominance. BRAF mutations were absent in 16 of 16 cases tested. Pathogenic NRAS mutations were detected in 3 of 11 cases tested and were associated with shorter overall survival compared to those without NRAS alterations, but the presence of NRAS mutations did not correlate with PRAME expression. In conclusion, an increase in PRAME expression and the presence of a pathogenic NRAS were both associated with a worse prognosis in mucosal melanomas.Users may view, print, copy, and download text and data-mine the content in such documents, for the purposes of academic research, subject always to the full Conditions of use:

Solitary fibrous tumor (SFT) is an uncommon fibroblastic neoplasm with considerable risk of local recurrence. SFT is histologically characterized by bland spindled-to-epithelioid cells in alternating hyper-and hypocellular zones, a "patternless pattern," ectatic "staghorn" vessels with variable edematous perivascular stroma, and thick ropey collagen.Cytologically, smears are variably cellular with spindled-to-epithelioid cells with oval nuclei, wispy cytoplasm, multiple inconspicuous nucleoli, and occasional nuclear pseudoinclusions. Small vessels and bare/stripped nuclei are generally present while mild atypia is not uncommon. STAT6 nuclear expression is the most useful immunohistochemical stain and is the product of a NAB2-STAT6 gene fusion. SFTs with mediastinal involvement may be diagnostically challenging due to proximity to vital structures and anticipated patient risks. Endobronchial and endoscopic ultrasound-guided fineneedle aspiration (EBUS/EUS-FNA) are minimally-invasive tissue sampling methods that provide diagnostic material while minimizing patient risk, and the mediastinum is accessible by both procedures. Small aspirate samples and SFT nonspecific features can compound the diagnostic difficulty, although familiarity with the cytologic, morphologic, immunophenotypic, and genetic features of SFTs assist the pathologist in confirming the diagnosis. Pathologists must also be aware of high-risk SFT features to ensure appropriate therapy and management. Case #1 describes a recurrent mediastinal SFT with high-risk features sampled by EUS-FNA. Case #2 describes a primary diagnosis of mediastinal SFT with malignant behavior made on an EBUS-FNA specimen. K E Y W O R D S endoscopic ultrasound, fine-needle aspiration, mediastinum, solitary fibrous tumor, STAT6

Background-Large cell calcifying sertoli cell tumor (LCCSCT) is an exceedingly rare lesion of the testicle. It is most often seen in patients with Carney complex (CNC) or Peutz-Jeghers syndrome (PJS). We now report the first pediatric patient with what appears to be bilateral LCCSCT and no other conditions or a genetic syndrome, such as PJS or CNC, have been associated with it.

Solid pseudopapillary tumor (SPT) of the pancreas is an extremely rare pancreatic tumor. It usually goes undetectable for a prolonged period of time given its lack of clinical symptoms. But when detected, it has a malignancy potential of 15%. Here we present a case of SPT diagnosed incidentally in a 17-year-old man during a routine evaluation for an abdominal trauma.

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