Hidradenoma papilliferum occurring on the nasal skin.

Hidradenoma papilliferum is a rare benign neoplasm that usually occurs in the female anogenital area. We present a 43-year-old female with a non-anogenital (ectopic) hidradenoma papilliferum on her nose. The patient had had a skin-colored subcutaneous nodule on her nose for 7 years. The histopathological findings showed variously shaped cystic spaces in the tumor. And the lumina were surrounded by a single or double layer of cell which showed decapitation secretion. In the English dermatological literature, only one case of ectopic hidradenoma papilliferum arising in nasal skin has been reported. Hence we suggest hidradenoma papilliferum occurring on the nasal skin is a peculiar and interesting event.

Giant acquired digital fibrokeratoma occurring on the left great toe.

Acquired digital fibrokeratoma is an uncommon, benign fibrous tumor which usually occurs in adults as a solitary lesion. The most frequent locations are fingers and toes and the size of the tumor is generally small, around 3~5 mm. An 18-year-old female presented with a solitary, skin-colored, round and protruded nodule of the left great toe. The size of nodule was 2.5×1.6×1.4 cm. Histopathologic examination revealed typical findings of acquired digital fibrokeratoma. Herein, we report a giant acquired digital fibrokeratoma.

A case of linear lichen planus pigmentosus.

Lichen planus pigmentosus (LPP) is chronic pigmentary disorder that shows diffuse or reticulated hyperpigmented, dark brown macules on the sun-exposed areas such as the face, neck and other flexural folds. Clinically, it is different from classical lichen planus because LPP has a longer clinical course and it manifests with dark brown macules. In case of LPP, involvement of the scalp, nail or mucosal area is rare. The histopathological findings of the lesions show an atrophic epidermis, the presence of melanophages and a vacuolar alteration of the basal cell layer with a sparse lymphohistiocytic lichenoid infiltration. Although there have been a few reports of LPP, there have only 3 cases of linear LPP along the lines of Blaschko in the Korean dermatologic literature. Our patient had lesions on the neck and chin with a linear pattern. In this report, we describe a very rare case of LPP with a linear distribution related to Blaschko's lines on the neck and chin areas.

A case of linear focal elastosis with a family history.

Linear focal elastosis is an uncommon disorder typically occurring in the back region, which clinically presents as band-like striae, having a histological focal increase in abnormal elastic fibers. Until now, linear focal elastosis occurring in patients with a family history have been rarely reported. Here, we present one such case, of linear focal elastosis which occurred in a brother and sister.