Primary non-Hodgkin's lymphoma of the salivary gland: A spectrum of lymphoepithelial sialadenitis, low-grade B-cell lymphoma of mucosa-associated lymphoid tissue with transformation to high-grade lymphoma.

Lymphoid infiltrates of the salivary gland can be either reactive or neoplastic. The reactive lesion, lymphoepithelial sialadenitis (LESA) may be associated with Sjogren's syndrome (SS) or may occur as an isolated salivary gland enlargement. Patients with LESA/SS have a particularly high risk of subsequently developing lymphoma, which is a low-grade mucosa-associated lymphoid tissue (MALT) type lymphoma of the salivary gland. We document a rare case of primary non-Hodgkin's lymphoma of the parotid gland arising in the background of LESA and with a rare example of transformation from low grade to high-grade B cell lymphoma of MALT type.

A Case of Low Grade MALT Lymphoma Presented as Submucosal Tumor without Mucosal Lesion / 대한소화기내시경학회지

Low grade mucosa-associated lymphoid tissue (MALT) lymphoma is a very indolent disease and can achieve complete remission with only localized treatment unlike the low grade B-cell lymphoma originating from peripheral lymph nodes. The endoscopic finding of the low grade gastric MALT lymphoma is usually presented as multiple and superficial erosions or ulceration. We recently experienced one case of low grade gastric MALT lymphoma without any mucosal lesion. The patient was initially considered as a submucosal tumor originating from the proper muscle layer of stomach and underwent the subtotal gastrectomy. But the submucosal tumor was confirmed to the low grade gastric MALT lymphoma without H. pylori infection.