Reticulohistiocytosis（皮膚型）

RETICULOHISTIOCYTOSIS : CUTANEOUS FORM

I．はじめに

　皮膚に結節状皮疹を作り，網内系細胞よりなる疾患群の1つにreticulohistiocytomaと称する疾患がある。その疾患概念はまだ明確化されたとはいえないが，近時この種の疾患に対する関心が増したせいか，かかる病名が適切と思われる症例が本邦においても数例報告されている。本症の如き疾患では診断の殆んどが組織検査に負う為，鏡検によりはじめて正しい診断が成されるのが普通で，臨床上その特徴はきわめて少ないものである。ただ本症と殆んど同一の組織像をとりながら，皮膚の他に関節・骨・粘膜などを侵す全身型reticulohistiocytosisについては，その臨床症状は有力な診断的根拠となるものと考える。

　著者は最近，臨床的に皮膚線維腫若しくは粉瘤が疑われた皮下結節で，病理組織所見よりreticulohistiocytosisなる病名が最も適当と思える症例を経験したので之を報告し，該疾患と近縁関係にある疾患，殊に本症の全身型即ちOrkin等のいうmulticentric reticulohistiocytosisとの関連をいささか考按したので述べてみたい。

　Reticulohistiocytoma or Reticulohistiocytosis belongs to a group of reticulosis with many multinucleated giant cells. There are two forms in this disease-systemic and cutaneous form. The former affects the mucous membrane, joints etc as well as skin, while the latter affects the skin alone.

　A case of solitary lesion of the cutaneous form was reported.

　A 26-year-old businessman found a nodule without subjective sensation on the left retroauricular region. No causative injury such as trauma could be proved. The nodule was 1.2×0.7 cm in size at his first visit but, when he had operation, its size had become as half as its original size.

　Histologic specimen showed well circumscribed granulomatous infiltration composed of reticulohistiocytic cells mixed with multinucleated giant cells in the deep dermis. The protoplasma of the giant cell looked like smoked glass and contained irregularly distributed compound substance of carbohydrates and lipids.

Differential diagnosis from systemic form of this disease was discussed.