Journal of Pathology and Translational Medicine

Case Reports

Benign Lymphoepithelial Cyst: A case report.: Jin Haeng Chung, Gyeong Hoon Kang, Je G Chi; Korean J Pathol. 1996;30(6):551-553.

Abstract PDF: An intraparotid benign lymphoepithelial cyst is a rare disease characterized by unilateral painless swelling of parotid region. The histogenesis is controversial. Surgical excision is recommended for diagnosis and curative treatment. We present a case of benign lymphoepithelial cyst arising in a patient with neurofibromatosis. A 46-year-old woman presented with a slowly growing multilocular cystic mass in the left cheek. The cystic mass measured 4 cm in maximal outer diameter and the cystic wall was thick and yellowish pale to gray, soft with well circumscribed margin. Microscopically, the multilocular cyst was lined by stratified squamous epithelium for the most part and underlying lymphoid tissue aggregates with follicles and sharply demarcated from adjacent salivary parenchyma which is of normal appearance and without lymphoid aggregates. Since this lesion is absolutely benign, it is important to separate this benign cyst from cystic salivary gland tumors.

A Branchial Cleft Cyst-Like Lymphoepithelial Cyst in the Thyroid Gland: A case report.: Gil Hyun Kang, Jee Soo Kim, Haing Sub R Chung; Korean J Pathol. 1999;33(7):533-536.

Abstract PDF: The lymphoepithelial cyst (LEC) rarely occurs in the thyroid gland. The LEC has been thought to be related to developmental rest, namely solid cell nest, which is derived from ultimobranchial body. We report a case of lymphoepithial cyst in a 34- year-old woman clinically diagnosed with Hashimoto's thyroiditis. The cyst was located in mid to lower portion of the left lobe. It was a single unilocular cyst, which for the most part was lined with squamous epithelium, and at certain foci with ciliated columnar epithelium. The cyst wall showed a dense lymphocytic infiltration, numerous lymphoid follicles with germinal centers and admixed thyroid follicles. This morphology is similar to the branchial cleft cyst, with the exception of the thyroid follicles in the cyst wall. Near the cyst were several solid epidermoid cell nests. Immunohistochemical stain of this cyst-lining epithelium and solid cell nests showed CEA positivity. In view of the similarity in histomorphology and CEA positivity to branchial cleft cyst of the lateral neck, the LEC of the thyroid could also have been of branchial origin. However, the admixed thyroid follicles in the cyst wall suggests that the LEC of the thyroid gland might have derived from another branchial cleft as a ultimobranchial body, because it has the potential for thyroid follicular differentiation.

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