Taro Shinogi

Changes in the number of Merkel cells with the hair cycle in hair discs on rat back skin

Background  Hair discs are known to contain a large number of Merkel cells and are ideal for investigating Merkel cell biology. Hair follicles, which are important elements of hair discs, undergo unique cyclical morphological and biological changes.

Cutaneous Sporotrichosis with Refractory and Reinfectious Lesions in a Healthy Female

We report a 71‐year‐old Japanese healthy female with an unusual clinical course of sporotrichosis; she developed infectious lesions on the face and the left upper limb at different periods. The initial lesion appeared on her right cheek and nose in 1992. Histopathologic and fungal examinations comfirmed the diagnosis of sporotrichosis. She was treated with oral potassium iodide and/or itraconazole and topical heat therapy. She had three recurrences and her facial plaque, which was resistant to several conventional treatments, was eventually excised and then grafted in 1996. After the surgical procedure, oral medication was continued for two months. In 2001, new lesions appeared on her left hand and forearm, which were anatomically different from the former lesions. Based on histopathologic and mycological findings, we confirmed reinfection with sporotrichosis. She was again treated with potassium iodide. The cutaneous lesions completely resolved after 26 weeks without surgical treatment.

Atrophic dermatofibrosarcoma protuberans with diffuse eosinophilic infiltrate

Atrophic dermatofibrosarcoma protuberans (atrophic DFSP) is a variant of dermatofibrosarcoma protuberans (DFSP), and is clinically characterized by depressed lesions. We report a patient with a typical atrophic DFSP lesion with marked eosinophilic infiltration. The patient was a 55‐year‐old woman with a dark‐red, depressed lesion in the epigastric region. Histopathological examination of the lesion showed proliferation of fibroblast‐like cells in a storiform pattern in the dermis and subcutaneous tissue. Immunohistochemical staining of tumor cells was positive for CD34. The lesion was histopathologically typical of DFSP, but no elevated lesion was clinically observed. Thus, a diagnosis of atrophic DFSP was made. Moreover, this tumor tissue exhibited marked eosinophilic infiltration. To our knowledge, they are no reports of eosinophilic infiltration in DFSP tissue. Therefore, this seems to be an extremely rare case of DFSP.