Primary Small B-cell Lymphoma (MALT Lymphoma) at Lingual Tonsil: A Case Report.

Aims: Primary non-Hodgkin’s lymphomas of the oropharyngeal region are rare. We report a case of a small B-cell lymphoma (MALT lymphoma) involving base of tongue. The patient was successfully treated with wide excision of the lesion followed by radiotherapy. Presentation of Case: A 75-year-old female Caucasian patient was referred to our clinic with complaints of foreign body sensation in the throat and progressively worsening snoring over 4 months. Oropharyngeal examination revealed a 3x3-cm smooth mass originating from the left side of the base of tongue and moving with protrusion of the tongue. Excisional biopsy revealed a low-grade small B-cell lymphoma with lambda monoclonal plasmacytic differentiation [extranodal marginal zone lymphoma of mucosaassociated lymphoid tissue (MALT) with lambda monoclonal plasmacytic differentiation]. The neoplastic population was consisted of small lymphoid B-cells and lambdamonoclonal plasma cells. Lymphoid cells showed CD20(+), CD5(-), CD23(-), CD10(-), BCL-6(-), IgD(-), BCL-2(+). In the neoplasm were seen few mitoses, and cellular proliferation marker Ki-67 was approximately 15%. Magnetic resonance imaging of the head and neck showed a well-circumscribed solid mass originating from the base of left side tongue. Bone marrow aspiration biopsy showed no evidence of disease. Computerized tomographic scans of the thorax and magnetic resonance imaging of the abdomen showed no adenopathy. Tumor was determined to be at Stage I. Discussion and Conclusion: Primary non-Hodgkin’s lymphomas involving oropharyngeal region should be considered in differential diagnosis of all lesions located in this region. To our knowledge, a case of small B-cell lymphoma of the base of the tongue is rarely reported. An appropriate evaluation of the clinical presentation along with histopathologic and immunohistochemical evaluation of biopsy specimen may aid in the diagnosis and effective treatment.