Vimentin Positive Primary Thyroid Diffuse Large B-Cell Lymphoma: cytological diagnosis of two cases

Swati Bhardwaj,Ashish Kumar Mandal,Charanjeet Ahluwalia

doi:10.21276/apalm.1137

Abstract

Primary thyroid lymphomas are rare tumours of thyroid accounting for 5% of all thyroid tumours. Diffuse large B cell lymphoma is one of the most common type of primary thyroid lymphoma. Here we are presenting two rare cases of primary thyroid lymphoma. The first case is of a sixty year old female who presented with a rapidly enlarging thyroid mass, causing compressive symptoms. Radiological investigations revealed deviation and compression of trachea by the mass. Fine needle aspiration was performed, and routine as well as liquid based cytology smears were prepared. Smears revealed features of diffuse large B cell lymphoma of thyroid. Immunocytochemistry was performed that confirmed the diagnosis, and also revealed vimentin positive nature of the neoplasm, that has been shown to confer some degree of resistance to chemotherapy. A tru cut biopsy was performed that reconfirmed the diagnosis, and also helped in determining Ki67 proliferation index of the tumour that determines the aggressive nature of non-Hodgkin’s lymphomas. The second case is of a seventy year old woman who presented with a rapid enlargement of thyroid over a period of three months, leading to difficulty in breathing and dysphagia. Fine needle aspiration was performed that showed features of immunoblastic type of DLBCL. The diagnosis was confirmed by immunocytochemistry, which also showed vimentin positivity. These two cases are important for their rarity, especially being vimentin positive, diagnosed on cytology with the aid of immunocytochemistry. DOI: 10.21276/APALM.1137

Highlights

Primary thyroid lymphoma is a rare entity and accounts for only 5% of all thyroid malignancies and approximately 3% of all non-Hodgkin’s lymphoma. [1, 2] There is an overall female predominance with a female: male ratio of 3:1. [3, 4] They typically occur in middle to old aged individuals
[7] The underlying pathogenesis of primary thyroid lymphoma is not exactly known, but is attributed to chronic antigenic stimulation leading to the development of intra-thyroid lymphoid tissue as is seen in Hashimoto’s thyroiditis
Fine needle aspiration cytology plays a vital role in diagnosing thyroid lesions

Summary

Introduction

Primary thyroid lymphoma is a rare entity and accounts for only 5% of all thyroid malignancies and approximately 3% of all non-Hodgkin’s lymphoma. [1, 2] There is an overall female predominance with a female: male ratio of 3:1. [3, 4] They typically occur in middle to old aged individuals. [5] Most thyroid lymphomas are of B cell origin. [6]The most common presentation of thyroid lymphoma is a rapidly enlarging, painless goitre. [6]The most common presentation of thyroid lymphoma is a rapidly enlarging, painless goitre. Other symptoms such as dyspnoea, dysphagia, and hoarseness may arise as a result of the pressure effects of the mass. [7] The underlying pathogenesis of primary thyroid lymphoma is not exactly known, but is attributed to chronic antigenic stimulation leading to the development of intra-thyroid lymphoid tissue as is seen in Hashimoto’s thyroiditis. This explains why the risk of development of primary thyroid lymphoma is 40-80 times higher in patients of Hashimoto’s thyroiditis. It is important to evade surgery by establishing diagnosis on FNA beforehand

Case Reports

Findings

Discussion

Conclusion