title: Multilocular thymic cyst associated with follicular hyperplasia: clinicopathologic study of 4 resected cases.
abstract: We report here 4 cases of multilocular thymic cysts (MTCs) with reactive lymphoid follicular hyperplasia. They were admitted to our hospital to examine anterior mediastinal masses demonstrated on chest computed tomographic scans. Three patients presented high-grade intermittent fever, and 2 patients were associated with Sjogren syndrome with elevated serum antinuclear antibody levels. All patients were subjected to extended thymectomy. Interestingly, their fever disappeared immediately after surgery. Histologically, the lesions were characterized by several cystic spaces separated by various thick walls with dense lymphoid tissue containing large reactive germinal centers. The inner cyst walls were lined by flattened cuboidal epithelia in some portions. Columnar epithelia with focal cilia were partially observed in 2 cases. These pathological findings led to a diagnosis of MTCs that were thought to result from cystic transformation of medullary duct derivatives by acquired inflammatory processes. The pathological findings, together with clinical courses of our cases, suggest that inflammation accompanied by autoimmune diseases may play, in part, an important role in the development of MTCs.
authors.affiliation: Department of First Pathology, Juntendo University, School of Medicine, Tokyo 113-8421, Japan. izumi@med.juntendo.ac.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Izumi
authors.forename: Bunsei
authors.initials: B
authors.lastname: Nobukawa
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Takahashi
authors.forename: Toshio
authors.initials: T
authors.lastname: Kumasaka
authors.forename: Hideaki
authors.initials: H
authors.lastname: Miyamoto
authors.forename: Akio
authors.initials: A
authors.lastname: Yamazaki
authors.forename: Satoshi
authors.initials: S
authors.lastname: Sonobe
authors.forename: Toshimasa
authors.initials: T
authors.lastname: Uekusa
authors.forename: Koichi
authors.initials: K
authors.lastname: Suda
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008476:Mediastinal Cyst / Q000150:complications / Q000473:pathology* / Q000601:surgery; D008875:Middle Aged; D013902:Radiography, Thoracic; D012859:Sjogren's Syndrome / Q000150:complications / Q000473:pathology; D013950:Thymus Gland / Q000473:pathology* / Q000601:surgery; D013952:Thymus Hyperplasia / Q000150:complications / Q000473:pathology* / Q000601:surgery; D016896:Treatment Outcome