Noriko Yamashita

Dermal Nerve Sheath Myxoma

A case of dermal nerve sheath myxoma on the left palm of 26‐year‐old Japanese man is presented. We examined this tumor by light and electron microscopies. On light microscopic examination, this tumor was characterized by a multilobulated myxoid tumor composed of stellate cells in an abundant mucous matrix. This histological feature resembled previously reported cases of dermal nerve sheath myxoma. On electron microscopic examination, the findings of these tumor cells were similar to those of the perineurial cells. These microscopical examinations have provided evidence for an origin from perineurial cells rather than Schwann cells.

Cutaneous Eruptions Induced by Granulocyte Colony‐stimulating Factor in Two Cases of Acute Myelogenous Leukemia

Recombinant human granulocyte colony‐stimulating factor (rhG‐CSF) induced cutaneous eruptions in two cases of acute myelogenous leukemia. In both cases, the eruptions appeared during rhG‐CSF therapy for neutropenia induced by the remission‐induction chemotherapy and disappeared rapidly after the discontinuance of rhG‐CSF therapy. Histopathology of those eruptions revealed dermal cell infiltrations consisting of some neutrophils and atypical cells. It was interesting that, although there were no leukemic cells in the peripheral blood or bone marrow, eruptions containing many leukemic cells appeared. The mechanism of the appearance of these eruptions was unclear, but it was considered that a few leukemic cells might have responded to rhG‐CSF and proliferated in the skin.

Clinical, Histological, and Immunohistological Studies of Postoperative Erythroderma

We report 7 cases of acute fatal illness characterized by fever, diffuse erythematous rash, and progressive leukopenia occurring 10 days after surgical operation. The outcome was uniformly fatal. The biopsy findings consisted of eosinophilic individual necrosis of epidermal cells, satellite cell necrosis, basal liquefaction degeneration, and scanty cell infiltration into the dermis. T lymphocytes were found in the epidermis but Langerhans cells disappeared. These findings are compatible with acute graft‐vs‐host disease following blood transfusion. Explanations based upon drug allergy, infection, toxic shock syndrome, or toxic epidermal necrolysis seem less reasonable.

Reactivity and Persistence of Local Immunological Memory on Murine Contact Hypersensitivity

In a rechallenge system examining murine contact hypersensitivity to DNFB in BALB/c mice, the reactivity to the specific antigen at the previously responded site and the persistence of an immunological memory were investigated. Flare‐up reactions were induced 4 weeks after the first challenge only at the previously responded site by local or systemic administrations of minute quantities of a specific antigen. The intensity of ear swelling was dependent on the quantity of applied antigen at the time of the rechallenge. The local hypersensitivity to the specific antigen observed in the previously responded site and the regional lymph node persisted for at least 1 year.