MALT lymphomas

Abstract

Mucosa-associated lymphoid tissue (MALT) lymphomas occur in a variety of organs, including the orbit, conjunctiva, salivary glands, skin, thyroid gland, lungs, stomach, and intestine. These tumors are often localized and of indolent clinical behavior. Diagnosis is made by pathologic evaluation of a tissue biopsy. Careful staging is mandatory and tailored to the initial presentation. Staging includes a history and physical, chemistries, computed tomography scan, and bone marrow biopsy. This information is supplemented with an ear, nose, and throat consultation, esophagogastro-duodenoscopy, colonoscopy, endoscopic ultrasound of the stomach, and cytogenetic/immunohistochemical analysis of the tumors. Treatment is tailored to organ involvement and stage at presentation. Eradication of Helicobacter pylori using a triple anti-H. pylori regimen approved by the US Food and Drug Administration is standard therapy for all H. pylori-positive gastric MALT lymphomas. Endoscopic ultrasound- and computed tomography-staged gastric MALT stage IE tumors will achieve a complete response with this approach in approximately 60% to 90% of patients (the more superficial the tumor, the better the response). Patients with tumors that are T4 node-positive Musshoff stage IIE1 and IIE2 or tumors with adverse cytogenetics should receive radiotherapy or surgery with or without radiotherapy. Tumors with a significant high-grade component or large cell tumors with a minor low-grade MALT component should receive CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone)-based chemotherapy. Localized MALT lymphomas of the orbit, conjunctiva, salivary glands, and thyroid gland are treated successfully with radiotherapy. Surgery as first-line therapy for gastric MALT lymphomas was replaced by attempts at organ preservation. In the past, margin-free surgical excision or tumor debulking followed by radiation therapy and chemotherapy has been highly effective for gastric MALT lymphomas. Therefore, surgical excision of large cell or bulky tumors of the stomach, thyroid, lung, and salivary gland, followed by adjuvant radiotherapy or chemotherapy, may still be an important consideration in selected patients. Surgery still has a role for patients with relapsed or refractory low-grade disease and life-threatening hemorrhage. Disseminated MALT lymphomas are incurable and are treated primarily with chemotherapy according to symptoms.

Synchronous Lymphomas Arising in Ipsilateral Parotid and Submandibular Glands

“…9 Treatment is usually surgical excision followed or not by adjuvant radiotherapy and/or chemotherapy. 10 To our knowledge, this combination of synchronous MALT lymphomas in major ipsilateral salivary glands such as the one presented in our patient has not been reported previously in the medical literature.…”

Tracheal stenting for primary tracheal mucosa-associated lymphoid tissue lymphoma

“…Although MALT lymphoma occurs most frequently in the gastrointestinal tract, they can also rise in various non-gastrointestinal sites, such as the salivary gland, conjunctiva, thyroid, orbit, lung, breast, kidney, skin, liver, uterus, and prostate [3]. Among the non-gastrointestinal MALT lymphomas, the pulmonary lymphomas are the most frequent, with figures of up to 19% among MALT lymphomas [4]. In spite of this, a primary presentation of MALT lymphoma affecting the trachea is very rare.…”

Primary Mucosa-Associated Lymphoid Tissue Thyroid Lymphoma: A Rare Thyroid Neoplasm of Extrathyroid Origin

“…In patients with localized disease, as in our patient, the preferred treatment is total thyroidectomy while the benefit from applying radiotherapy in a total dose of 40 Gy, or chemotherapy, is questionable and with its toxicity being a major issue. 1,2,6,8 , 17–20 …”

“…1–3 MALT lymphomas, which account for 25% of primary lymphomas, arise mainly in the stomach (60–70%), but they also can be found in organs such as the orbit, salivary gland, lung, intestine, liver and thyroid gland. 2 Normally, thyroid gland is devoid of lymphoid tissue while this is reversed during the course of autoimmune diseases such as Hashimoto's thyroiditis. 1–3 It has been evident that thyroid MALT lymphomas occur in 0.5% of the cases with Hashimoto's thyroiditis, even after a long period of lymphocytic infiltration which reaches as long as 30 years.…”