Satoko Shimizu

Coexistence of psoriasis and an unusual IgG-mediated subepidermal bullous dermatosis: identification of a novel 200-kDa lower lamina lucida target antigen

Summary Bullous pemphigoid (BP) is characterized by autoantibodies against 230‐ and 180‐kDa hemidesmosomal antigens located in the most superficial layers of the basement membrane zone (BMZ). Histologically. there is a predominance of eosinophils in the infiltrate. In a psoriatic patient, we identified an unusual autoimmune subepidermal bullous eruption which clinically resembled BP, but which was characterized by IgG autoantibodies against a novel 200‐kDa lower lamina lucida component, Histologically there was a predominance of neutrophils in the infiltrate.

Metastatic testicular choriocarcinoma of the skin. Report and review of the literature.

Choriocarcinoma is a malignant growth of trophoblastic cells characterized by secretion of human chorionic gonadotropin. Choriocarcinoma usually arises from fetal trophoblasts and rarely arises from germ cells in the testis or ovary or derives from dedifferentiation of other carcinomas. Skin metastasis of choriocarcinoma is rare: only seven cases have been reported in the English and Japanese literature. We report the case of a 22-year-old Japanese man with pure choriocarcinoma of the testis who developed skin metastases that presented as multiple reddish nodules. Microscopic examination of both the primary lesion of the testis and the cutaneous metastasis demonstrated the typical histologic features of pure choriocarcinoma. The patient died 3 months after the initial onset of skin metastasis. Review of the literature indicates that skin metastasis of choriocarcinoma usually occurs as a nodular lesion with the histologically typical feature of the primary disease and signals of poor prognosis.

Is cutaneous plasmacytosis a distinct clinical entity

We describe a Japanese patient with cutaneous plasmacytosis whose clinical course we observed for 5 years. We also review 26 patients with this condition, including 24 Japanese and two non-Japanese, reported in detail. This review revealed that this condition has characteristic clinical and pathologic features and should be considered a distinct clinical entity. The reason for the predominant occurrence of cutaneous plasmacytosis in Japanese patients is unknown.

Subcutaneous nodules on the buttocks as a manifestation of dialysis‐related amyloidosis: a clinicopathological entity?

Summary  While β2‐microglobulin amyloidosis occurring in patients undergoing long‐term dialysis is frequently associated with joint involvement, skin lesions have rarely been encountered. We report a 57‐year‐old man with extensive subcutaneous amyloid deposition forming large nodules on the buttocks; the patient had been on maintenance dialysis for 28 years. Although this condition is rare, a review of the literature indicates that the majority of such lesions occur around the buttock region.

Malignant epithelioid Schwannoma of the skin showing partial HMB-45 positivity

A malignant epithelioid schwannoma occurred on the right second toe of a 30-year-old Japanese man. It was a firm, flesh-colored, benign-appearing nodule and measured 13 x 9 mm in diameter and 6 mm in height. To our knowledge, this is the first case of malignant epithelioid schwannoma occurring on the toe. Histopathology was characterized by a circumscribed nodule in the dermis that predominantly consisted of atypical large epithelioid cells with some spindle cells whose proliferation was similar to that of the Verocay bodies seen in ordinary schwannoma. Fontana-Masson staining demonstrated no melanin pigment in the tumor at the light microscopic level. The eosinophilic cytoplasm contained abundant glycogen and was positive for S-100 protein and HMB-45, as usually seen in melanomas. Electron microscopy revealed that there was an abundance of long-spacing collagen in the extracellular matrix, and the cells contained numerous dense-cored granules. But no definite melanosomes were observed in any stage. As far as we are aware, this is the first case of a malignant epithelioid schwannoma showing HMB-45 positivity.

Immunohistochemical Study of Mixed Tumor of the Skin with Marked Ossification

We observed an unusual case of mixed tumor of the skin associated with marked ossification on the upper lip of a 68-year-old Japanese woman. The tumor was a well-circumscribed mass that measured 3 x 3 x 2 cm and contained exuberant bone formation with a marrow-like structure. Histological examination of the tumor showed that the bones occupied a quarter of the specimen. Except for the large bone formation, the tumor showed typical features of a tubulocystic type of mixed tumor. The bone was formed without intervening cartilage, suggesting the possibility of the direct deposition of osteoid by metaplastic cells. To our knowledge, no similar case of mixed tumor of the skin associated with marked bone formation has been reported.

Tropical-wood-induced bullous erythema multiforme.

We report a case of bullous erythema multiforme caused by an exotic wood, pao ferro (Machaerium scleroxylon). A 25-year-old female, a luthier (guitar maker) who often handles a variety of woods, developed bullous erythema multiforme. A patch test confirmed a positive reaction to one of the exotic woods, pao ferro. A subsequent accidental short contact with pao ferro 5 months following the first incidence induced a similar exudative erythema. Exotic woods such as pao ferro should be added to the list of contact allergens that can induce bullous erythema multiforme.

Localized linear IgA/IgG bullous dermatosis.

Linear IgA/IgG bullous dermatosis (LAGBD) is an auto-immune blistering disease characterized by the local accumulation of IgA- and IgG-class anti-basement membrane autoantibodies. It typically presents as a generalized pruritic vesiculobullous eruption. No cases of localized LAGBD have yet been reported. We report a case of a 78-year-old man with LAGBD localized to the perianal area. The patient complained of suffering from persistent ulcers around the anus for more than 3 years. Physical examination revealed several blisters and ulcers up to 2-cm in diameter around the anus. No lesions were found elsewhere on the body. Histological analysis of a skin biopsy revealed subepidermal blistering, while direct immunofluorescence showed the linear deposition of IgA and IgG antibodies at the dermoepidermal junction. Indirect immunofluorescence of normal human skin whose layers had been separated using 1M NaCl showed the binding of both IgA and IgG to the epidermal side. Immunoblotting demonstrated the presence of circulating IgA and IgG autoantibodies that bound to a 120-kDa protein. This is the first case of localized LAGBD whose skin lesions were restricted to the perianal region.

Cutaneous Manifestations of Helicobacter cinaedi Infection

Helicobacter cinaedi causes gastroenteritis and bacter-aemia, particularly in immunocompromised individuals. Although cellulitis is sometimes reported to accompany infection by this pathogen, the cutaneous manifestations are poorly understood. To clarify the characteristic cutaneous features, 47 cases of H. cinaedi bacteraemia experienced at Sapporo City General Hospital as nosocomial infection were retrospectively evaluated. Thirty-four percent (16 cases) of the patients showed cutaneous lesions. They all had sudden onset of erythemas accompanied by high temperature. The most common cutaneous manifestations were found to be superficial cellulitis, which results in painful erythemas or infiltrated erythematous plaques on the extremities. These skin lesions can be an early clinical indicator of H. cinaedi bacteraemia in the setting of nosocomial infection.

Keratosis follicularis squamosa (Dohi) : a follicular keratotic disorder well known in Japan

Keratosis follicularis squamosa (KFS) is a keratinizing disorder, which is well recognized in Japan but rarely reported in other countries. KFS is characterized by asymptomatic small scaly patches with a follicular plug that is scattered on the trunk and thighs. It is easily diagnosed by its characteristic appearance that was originally described in Japanese as ‘lotus leaves on the water’. We report a typical case of KFS and review the mainly Japanese literature. We conclude that KFS is a distinct clinical entity of unknown origin. World‐wide recognition of this disease should further clarify the prevalence and pathogenesis of this skin condition.