Linear psoriasis with porokeratotic eccrine ostial and dermal duct nevus.

Linear psoriasis is an uncommon form of psoriasis characterized by the linear distribution of the psoriatic lesions. It usually follows the lines of Blaschko with unilateral involvement. Poro keratotic eccrine ostial and dermal duct (PEODD) nevus is another rare dermatosis that follows Blaschko's line. The pathogenesis of linear psoriasis and PEODD nevus is unclear, but both could be best explained by a specific somatic mutation. Hence, it has been suggested that the mutation responsible for PEODD nevus would constitute a rare but critical psoriasis gene. In the literature, 1 case of linear psoriasis with PEODD nevus was reported, which may support this suggestion. This article describes another case of linear psoriasis and PEODD nevus. A 7-year-old boy had a 4-month history of multiple psoriasiform plaques, arranged in linear distribution, and had congenital linear hyperkeratotic papules and pits on the right side of his trunk and right arm.

TCR gene-rearranged, extranodal NK/T-cell lymphoma, nasal type, presenting as gyrate patches.

In the CD56+ cutaneous nasal-type NK/T-cell lymphoma strongly associated with latent EBV infection, subcutaneous or dermal nodules are the most common skin findings, but great morphologic heterogeneity has been noted including papules, infiltrated plaques, and ulcerated tumors, and TCR genes are mostly germline. We describe a case of nasal and nasal-type NK/T-cell lymphoma featuring multiple erythematous polycyclic patches on the trunk, which is similar to patch stage mycosis fungoides or other cutaneous T cell lymphoma. Immunohistochemical study of a skin biopsy specimen revealed CD2+, CD3epsilon+, CD56+, and CD45RO+ expression in the neoplastic cells. In situ hybridization using an anti-sense Epstein Barr virus early regions probe showed a positive reaction. However, clonal TCR beta gene rearrangement was found.