A Case of MALT Lymphoma in Parotid Gland Duct

ABSTRACT

PURPOSE: Primary malignant lymphomas of the salivary glands are uncommon. The parotid gland was most frequently involved, followed by the submandibular gland, minor salivary gland and sublingual gland. The most common subtype is mucosa-associated lymphoid tissue (MALT) lymphoma. We experienced a case of salivary MALT lymphoma involving parotid gland duct, so report a case with a review of the literature. METHODS: A 65 year old female presented with a palpable mass on the left side of her cheek. There was no clinical or laboratory evidence of pre-existing autoimmune disease. Preoperative facial and neck CT with contrast showed 2.1x1.7cm sized, ill defined, homogeneous low density mass near left masseter muscle, and no evidence of other enlarged lymph nodes. RESULTS: At operation, a yellowish oval shaped mass was found slightly adhered to middle portion of the parotid gland duct, measuring 2x1.5x0.7cm. Microscopic finding showed that centrocyte-like cells, monocyte B cells and plasma cells were diffusely infiltrated. Immunophenotyping was preformed on fixed section. The majority of the small cells were immunoreactive for the B cell marker CD20. Based on the typical histological findings supported by immunostaining, the mass was defined as MALT lymphoma. CONCLUSION: We report a very rare case of MALT lymphoma involving parotid gland duct in 65 year old female patient with clinical characteristics, histologic features and references.