Malignant Lymphoma of the Thyroid Gland

Abstract

We report a retrospective clinicopathologic study of 108 primary thyroid gland lymphomas (PTLs), classified using the REAL and proposed WHO classification schemes. The patients included 79 women and 29 men, with an average age of 64.3 years. All patients presented with a thyroid mass. The PTLs were classified as marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) or MZBL (n = 30), diffuse large B-cell lymphoma (DLBCL) with MZBL (n = 36), DLBCL without MZBL (n = 41), and follicle center lymphoma (FCL; n = 1). Excluding the FCL, features of lymphomas of MALT-type were identified in all groups, despite a follicular architecture in 23% of cases. Lymphocytic thyroiditis (LT) was identified in 94%. Ninety-one percent of patients presented with stage IE or IIE disease, whereas 69% had perithyroidal soft tissue infiltration. All patients were treated with surgical excision followed by adjuvant therapy (76%): chemotherapy (15%), radiation (19%), or a combination of radiation and chemotherapy (42%). Disease-specific survival was 82% at last follow up (mean, 82.8 mos) and 79% at 5 years. Statistically, stages greater than IE, presence of DLBCL, rapid clinical growth, abundant apoptosis, presence of vascular invasion, high mitotic rate, and infiltration of the perithyroidal soft tissue were significantly associated with death with disease. No patients with MZBL or stage IE disease died with disease. In summary, PTLs typically occur in middle- to older-aged individuals as a thyroid mass, with a predilection for females. Despite their histologic heterogeneity and frequent simulation of other lymphoma subtypes, virtually all PTLs are lymphomas of MALT-type arising in the setting of LT. Mixed DLBCL and MZBL are common. Overall, PTLs have a favorable outcome with appropriate therapy, but prognosis depends on both clinical stage and histology. MZBL and stage IE tumors have an excellent prognosis, whereas tumors with a large cell component or DLBCL or stage greater than IE have the greatest potential for a poor outcome.

Primary thyroid MALToma– a rare diagnosis of an unassuming thyroid nodule

“…Localized thyroid MALT lymphoma can be treated with surgical resection with 100% survival at 5 years [5,8–10]. Review of 103 cases done by Tsang et al with localized (stage IE/IIE) extra nodal MALT lymphoma had overall 5 years survival of 98% in 85 patients with extra nodal MALT lymphoma treated with radiation therapy alone [11].…”

“…Patients who present with enlarging tumors or symptoms of compression also have poorer prognosis [10]. Although this disease has excellent survival rate after treatment, the optimal follow-up remains controversial at present [5,10]. …”

“…Thyroid lymphomas are most commonly diffuse large B-cell lymphomas (60–80%), and only about 30% are extra nodal marginal zone lymphomas [3]. Primary thyroid MALT lymphoma is rare, accounting 6–28% of PTLs [5] and usually arises in the setting of chronic lymphocytic thyroiditis, such as Hashimoto’s thyroiditis [2]. The mean and median ages at diagnosis is between 65 and 75 years with 4:1 female predominance [5–7].…”

“…Primary thyroid MALT lymphoma is rare, accounting 6–28% of PTLs [5] and usually arises in the setting of chronic lymphocytic thyroiditis, such as Hashimoto’s thyroiditis [2]. The mean and median ages at diagnosis is between 65 and 75 years with 4:1 female predominance [5–7]. Co-occurrence of papillary thyroid carcinoma has also been reported [3,8].…”

Thyroid nodule: first manifestation of chronic lymphocytic leukaemia

“…C hronic lymphocytic leukaemia (CLL) is a lowgrade indolent neoplasm composed of small B lymphocytes in the peripheral blood, bone marrow, lymph nodes, and other tissues (1,2). The diagnosis of CLL requires the presence of more than 5 x 10 9 small monoclonal lymphocytes per liter in the peripheral blood (3).…”