術前のMR画像で病変内部の信号パターンに変化を認めた耳下腺リンパ上皮性嚢胞の1例 A case of lymphoepithelial cyst in the parotid gland with changes on MRI before operation
Lymphoepithelial cyst is characterized by a cyst wall, the inner layer of which consists mainly of squamous epithelium, overlying lymphatic tissue. Previously, this lesion has been referred to as a branchiogenic cyst, lateral cervical cyst, or benign lymphoepithelial cyst. This lesion frequently develops in the lateral cervical region or oral floor, but rarely develops in the parotid gland.<BR>We report on a 68-year-old man with a lymphoepithelial cyst in the parotid gland, which showed changes on MRI before operation. With the patient under general anesthesia, the lesion was extirpated. Histopathologically, the resected specimen suggested a lymphoepithelial cyst. Because the cyst contained a colloid substance, transformation of a liquid substance into a highly viscous colloid substance may have contributed to the changes on MRI. Many duct-like structures of the salivary gland were observed in the resected specimen, suggesting that the content was initially similar to saliva, and that these ducts were involved in subsequent changes in the liquid content. Furthermore, a lymphatic tissue layer with a marginal sinus-like structure was found below the capsule. Therefore, we speculated that the parotid glandular epithelium invaded the parotid lymph nodes, leading to cyst formation.
日本口腔外科学会雑誌 52(9), 502-506, 2006-09-20
Japanese Society of Oral and Maxillofacial Surgeons