Liang S B, Ohtsuki Y, Sonobe H, Iwata J, Furihata M, Ido E, Watanabe R, Ohmori K, Ohtsuka S
Department of Pathology, Kochi Medical School, Japan.
Pathol Res Pract. 1996 Dec;192(12):1283-7. doi: 10.1016/s0344-0338(96)80170-1.
The association of multilocular thymic cysts (MTC) with thymoma is exceedingly rare, and the pathogenesis of this combination is controversial. We describe the case of a 42-year-old man with an anterior mediastinal mass found to contain MTC and thymoma. A multilocular cystic mass, measuring 13 x 6.5 x 2 cm, was found in the right lobe of the thymus, and contained a 4.7 x 2 cm thymoma in its center. Microscopic thymomas, lipomatously involuted remaining thymic tissue, and lymphoid follicles with germinal centers were found in the walls of MTC as well as in the left thymic lobe. Non-specific chronic inflammation was also present in the walls. In addition, microcysts, which were only found at the periphery of the thymoma and covered with epithelium, might have been formed secondarily by dilatation of the perivascular spaces and of Hassall's corpuscles. These findings suggest that a chronic inflammatory process was responsible for the early formation and enlargement of this patient's MTC, and that while the cavities of the MTC expanded to various degrees, the thymoma, which originated from one of the microscopic thymomas in the walls of MTC, increased in size, and grew to involve the remaining thymic tissue.
多房性胸腺囊肿（MTC）与胸腺瘤的关联极为罕见，这种组合的发病机制存在争议。我们描述了一例42岁男性患者，其前纵隔肿块被发现含有MTC和胸腺瘤。在胸腺右叶发现一个多房性囊性肿块，大小为13×6.5×2 cm，中心含有一个4.7×2 cm的胸腺瘤。在MTC壁以及左胸腺叶中发现了显微镜下的胸腺瘤、脂肪化生残留的胸腺组织以及带有生发中心的淋巴滤泡。壁内还存在非特异性慢性炎症。此外，仅在胸腺瘤周边发现且被上皮覆盖的微囊肿，可能是由血管周围间隙和哈氏小体扩张继发形成的。这些发现表明，慢性炎症过程是该患者MTC早期形成和增大的原因，并且在MTC腔不同程度扩张的同时，起源于MTC壁内显微镜下胸腺瘤之一的胸腺瘤体积增大，并生长累及剩余的胸腺组织。
