Salivary Gland Lymphoma: Review of 11 Cases

Malignant lymphomas of the salivary glands are uncommon. Historically, they comprise 1.7% to 3.1% of all salivary neoplasms. The parotid glands are the most common site of occurrence, but submandibular, sublingual, and minor salivary gland involvement is well documented. A mass in the salivary gland, especially the parotid, may represent the initial manifestation of malignant lymphoma, or it may be part of a more generalized disease. Additionally, the vast majority of major salivary gland lymphomas are non-Hodgkin's lymphoma of B-cell lineage. In our review of 11 cases of salivary gland lymphoma at our institution, 8 patients were women and 3 were men. All were Caucasian with the exception of 1 African American. Age ranged from the third to the eighth decade with the average being 66 years. Nine out of 11 cases involved the parotid glands and all, with the exception of 1 case, represented primary disease. The other 2 cases involved the submandibular glands. A total of 4 patients had an underlying Sjogren's syndrome and went on to develop lymphoma (3 in the parotid and 1 in the submandibular gland). One patient was diagnosed with T-cell–rich B-cell lymphoma, 1 with small lymphocytic lymphoma/chronic lymphocytic leukemia, and 1 with lymphoplasmacytoid lymphoma. Two patients were diagnosed with low-grade follicular lymphoma, 1 of which represented metastatic disease to the parotid and which underwent subsequent transformation to an intermediate grade. Another patient was diagnosed with Mantle zone lymphoma, and the remaining 5 patients were diagnosed with mucosa-associated lymphoid tissue lymphoma, in 1 of which transformation into large B-cell lymphoma was documented. The clinicopathologic features, utilizing special and ancillary studies, treatment, and follow-up are presented. Malignant lymphomas of the salivary glands are uncommon. Historically, they comprise 1.7% to 3.1% of all salivary neoplasms. The parotid glands are the most common site of occurrence, but submandibular, sublingual, and minor salivary gland involvement is well documented. A mass in the salivary gland, especially the parotid, may represent the initial manifestation of malignant lymphoma, or it may be part of a more generalized disease. Additionally, the vast majority of major salivary gland lymphomas are non-Hodgkin's lymphoma of B-cell lineage. In our review of 11 cases of salivary gland lymphoma at our institution, 8 patients were women and 3 were men. All were Caucasian with the exception of 1 African American. Age ranged from the third to the eighth decade with the average being 66 years. Nine out of 11 cases involved the parotid glands and all, with the exception of 1 case, represented primary disease. The other 2 cases involved the submandibular glands. A total of 4 patients had an underlying Sjogren's syndrome and went on to develop lymphoma (3 in the parotid and 1 in the submandibular gland). One patient was diagnosed with T-cell–rich B-cell lymphoma, 1 with small lymphocytic lymphoma/chronic lymphocytic leukemia, and 1 with lymphoplasmacytoid lymphoma. Two patients were diagnosed with low-grade follicular lymphoma, 1 of which represented metastatic disease to the parotid and which underwent subsequent transformation to an intermediate grade. Another patient was diagnosed with Mantle zone lymphoma, and the remaining 5 patients were diagnosed with mucosa-associated lymphoid tissue lymphoma, in 1 of which transformation into large B-cell lymphoma was documented. The clinicopathologic features, utilizing special and ancillary studies, treatment, and follow-up are presented.