[Non-gastric mucosa-associated lymphoid tissue (MALT) lymphomas: analysis of 14 patients]

Mucosa-associated lymphoid tissue (MALT) lymphomas are a well defined group of B-cell non-Hodgkin's lymphomas, that arise in a wide variety of extranodal sites, most frequently in the stomach and related to Helicobacter pylori infection. The aim of the present study was to analyze the presenting features, natural history and outcome in 14 patients with non-gastric MALT lymphoma.

The main clinical data, treatment and outcome were recorded for the 14 patients with non-gastric MALT lymphoma diagnosed at a single institution in a 12 year period. The median age was 68 years and 13 patients were females. Diagnosis was made according to the REAL classification criteria.

The initial location was thyroid (3 patients), parotid (three), submaxilar gland (three), skin (two), Waldeyer's ring (one), breast (one), lung (one), small bowel (one), liver (one) and ovary (one). At diagnosis 3 patients had > or = 2 extranodal involved sites. Autoimmune disorders were present in 5 patients: Hashimoto's thyroiditis (three), Sjögren's syndrome (one) and both (one). Two patients had a poor performance status (ECOG > 1) and B-symptoms. Five patients (36%) were in stage IV, two of them because of bone marrow infiltration. All patients had a normal serum LDH level, and 5 had high beta 2-microglobulin level. The treatment consisted in surgical resection (2 patients), surgery and radiotherapy (one), surgery and chemotherapy (two), chemotherapy and radiotherapy (two) and chemotherapy alone (7 patients, three of them with doxorubicin-containing regimens). Twelve patients were evaluable for response. Complete response, partial response and failure rates were 75, 17 and 8%, respectively. Two of the 11 responders progressed, one of them with advanced stage disease. The actuarial 4-year disease-free survival was 77% (CI 95%: 47-100%). After a median follow-up of 3.4 years, 100% of the patients were alive.

Non-gastric MALT lymphomas may be associated with autoimmune disorders, may present as disseminated disease and have a very good outcome.