タケバヤシ　チアキ   Takebayashi Chiaki   竹林　ちあき    所属   東邦大学  医学部 医学科（大森病院）    職種   臨床准教授
言語種別	日本語
発表タイトル	Spontaneous regression of oral lymphomatoid papulosis in an elderly patient
会議名	第87回日本血液学会学術集会
学会区分	国内学会
発表形式	ポスター掲示
講演区分	一般
発表者・共同発表者	◎Naoki Onda†，Daisuke Nagase†，Ruka Suzuki 1†，Takayoshi Sumi†，Hirofumi Irita†，Susumu Ishihara†，Kentaro Narita，Chiaki Takebayashi†
発表年月日	2025/10/11
開催地 （都市, 国名）	神戸
開催期間	2025/10/10～2025/10/12
概要	Background: Lymphomatoid papulosis (LyP) is a CD30- positive cutaneous lymphoproliferative disorder characterized by recurrent, self- healing papulonodular lesions, predominantly affecting the extremities and trunk. Although clinically indolent, LyP shares histopathological features with more aggressive lymphomas, particularly primary cutaneous anaplastic large cell lymphoma (pcALCL), necessitating careful diagnostic differentiation. Case Presentation: An 80- year- old male presented with tongue pain and an intraoral mass. Examination revealed a 25 mm pedunculated lesion with coating on the dorsal tongue and an ulcerative lesion on the left buccal mucosa. FDG- PET/CT showed abnormal uptake at both sites. Histopathology revealed necrotic debris and bacterial colonies on the surface, with underlying infiltration of large atypical lymphoid cells and Hodgkin- like cells. Immunostaining showed CD3+, CD4+, CD8- , CD30+, TIA- 1+, and Granzyme B+. Although pcALCL was considered, the clinical course supported a diagnosis of LyP type C. Conservative management with oral hygiene was initiated, and complete spontaneous resolution occurred within one month. Discussion: Oral involvement of LyP is extremely rare. The patient, frail after cerebral infarction, had poor oral hygiene. Chronic mucosal inflammation due to bacterial colonization may have contributed to disease onset. Conclusion: Recognizing the potential for spontaneous resolution in oral LyP may help avoid unnecessary cytotoxic therapy and its associated risks.