Fine needle aspiration cytology of primary thyroid non-hodgkins lymphoma: Experience from a tertiary care center of North India.

Abstract

Twelve cases of Primary Thyroid Non-Hodgkin's Lymphoma (PT-NHL) were retrieved from the records suspected or diagnosed as NHL on fine needle aspiration cytology (FNAC) over a period of nine years from 2010-2018. During this period 5236 patients underwent thyroid FNAC;of these 685 cases were diagnosed under Bethesda Caregory V and VI. Thyroid NHL constituted 0.23 % of all thyroid FNA (12/5236 cases)and 1.7% (12/685) of all thyroid malignancies. Patients ranged in age from 40-61 years with Female:Male 7:5. All patients presented with thyroid enlargement (5-14 cms), and were of two months to five years duration. Patients had history of tobacco intake (smoking/chewing)in nine cases (75%). Thyroid function tests showed hypothyroidism in four (33%), positive antithyroid antibodies in three (25%) and; two cases(16.7%) were known cases of Hashimotos thyroiditis with follow up. Eight cases (66.7%) had monomorphic large cell morphology,other four had mostly intermediate cell types (33.3%). A panel of immunocyto/ histochemistry (ICC/ IHC) showed CD 19 and CD 20 positivity in all cases;sixof these could be correlated on Flow cytometry (FC) with expression of FMC7, CD20, CD19 with kappa light chain restriction (5) and Lambda (1). FC findings corroborated completely with IHC on biopsy sections. The final diagnosis were Diffuse large B cell Lymphoma (DLBCL,8) and MALT- Lymphoma(4). The follow up was available in DLBCL (4) and MALT- Lymphoma (1). CHOP therapy were given in all patients followed by radiotherapy in DLBCL; one patient of DLBCL died following pulmonary complications, rest are well and alive on follow-up. PT-NHL is rare in India. DLBCL is the commonest histological type reported. In the present study, tobacco exposure has shown strong association. Combined FNAC-FC provide definitive diagnosis and thus can replace histopathology reducing turn around time. FNAC -FC provides a definitive diagnosis and thus can reduce turnaround time.