It may present a diagnostic dilemma in the absence of cutaneous lesions and when deeply located. Physicians should be aware of the widening spectrum of manifestations of juvenile xanthogranuloma. An Immunophenotypic Study With A Reappraisal of Histogenesis Madeleine D. Kraus, etal. The dermal dendrocyte was previously proposed as the cell of origin for JXG on the basis of Factor XIIIa reactivity, a suggestion that does not fully explain the occasional xanthogranulomatous proliferations localizing exclusively to extracutaneous sites. None of those cases was reactive for CD1a, CD3, CD21, CD34, or CD35.
Histiocytic proliferations can mimic melanocytic tumors and vice versa.
The authors describe the clinical, histologic, and immunohistochemical findings of three predominantly mononuclear xanthogranulomas that were misdiagnosed as malignant melanoma by experienced pathologists. All lesions occurred in male patients ranging in age from 14 to 75 years. The tumors presented as dermal nodules, two of which were surrounded by an epidermal collarette and were ulcerated focally. The tumors were composed of a mixed population of large epithelioid and plump spindle cells with pink or pale cytoplasm arranged in nests and short fascicles. Occasional mononuclear cells had cytoplasmic vacuolar changes, but none had well-developed foamy cytoplasm.