Darier disease: Histopathology revisited.

ABSTRACT: Darier disease (DD) is a rare genodermatosis. Literature on this topic is overwhelmingly dominated by case reports with rare clinical presentations, which have mentioned the histopathologic features briefly. The aim of this study was to document the histopathology of DD. Skin biopsies diagnosed as Darier disease based on clinicopathologic correlation over 12 years were reviewed for various epidermal and dermal features. There were 16 patients included, who most commonly presented in the third decade, with slight female predilection. The most common clinical presentation was hyperpigmented, hyperkeratotic, papules and plaques (91%), with 69% affecting the trunk. In addition to the classic suprabasal acantholytic clefts, we noted some unusual features: absence of parakeratosis (19%), a cornoid lamella-like pattern (62%), follicular acantholysis (13%) and multiple foci of involvement within a single biopsy (63%). Features such as the presence of dyskeratotic cells and minimal dermal lymphocytic infiltrates were concordant with previous literature. The limitation of this study was the small sample size. To conclude, pathologists must be aware of the variations in histopathology of Darier's disease, especially when challenged with atypical clinical presentations. The Darier-like pattern is met within several acantholytic diseases, and clinicopathologic correlation has the last word in arriving at a diagnosis.

Primary Gastric Synovial Sarcoma in a Child: A Case Report and Review of the Literature.

Synovial sarcoma is a mesenchymal neoplasm that shows a specific t(X;18) translocation that leads to the formation of SS18-SSX gene fusions and is most commonly seen in soft tissues of the extremity. The gastrointestinal tract is a very rare site of involvement. We report a case of primary gastric synovial sarcoma in a 13-year-old male child. Synovial sarcoma should be included in the differential diagnosis when spindle cell neoplasms are encountered in the stomach. A high degree of suspicion, followed by the necessary immunohistochemistry and molecular studies, is required to make an accurate diagnosis.