Diffuse large B-cell lymphoma of the parotid gland: Cytological, histopathological, and immunohistochemical features: A rare case report

Abstract

Primary malignant lymphomas of the salivary glands are rare, accounting for 2-5% of salivary gland tumors and 5% of extranodal lymphomas, frequently seen in the parotid gland. There are single case reports mentioned in the literature. Clinical presentation is not characteristic and the disease is often overlooked with delay in diagnosis and treatment. We are reporting a case of bilateral parotid gland lymphoma in a 55-year-old male, presented with bilateral enlarged parotids. Magnetic resonance imaging (MRI) showed bilateral enlarged parotid glands with multiple well-defined intraparotid lesions. Fine Needle Aspiration Cytology (FNAC) of both showed mixed population of lymphoid cells with large monocytoid cells with scant cytoplasm, anisonucleosis with prominent nucleoli, and numerous mitoses suggestive of non-Hodgkin's lymphoma (NHL). Histopathology showed sheets of large lymphoma cells destructing the salivary acini and infiltrating the periparotid fat. Immunohistochemistry (IHC) showed diffuse CD20 positivity, B-cell lymphoma 6 protein (Bcl-6) was focally positive and negative for cluster of differentiation (CD) 3, CD5, CD10, and Multiple myeloma oncogene-1 (MUM1) which led to the diagnosis of NHL-Diffuse large B cell type.

Pediatric follicular lymphoma of the parotid gland

“…Considering the fact that extranodal lymphoma is usually diagnosed in the sixth decade of life, the occurrence of parotid lymphoma in the pediatric population is the rarest of all. Only sporadic case reports describe primary parotid lymphoma occurring in middle-aged adults [3-5]. In our case, histologic subtype revealed FL, which is a Bcell origin non-Hodgkin lymphoma.…”

Is Milan for kids?: The Milan System for Reporting Salivary Gland Cytology in pediatric patients at an academic children's hospital with cytologic‐histologic correlation

“…This study also reiterates a known pitfall in basaloid or round blue cell lesions of the head and neck, which includes pilomatricoma, and other benign dermal or subcutaneous neoplasms in pediatric patients, in addition to lymphoma. [25][26][27] In this study, 3 cases of pilomatricoma were identified involving the skin overlying the parotid gland area. The cases were diagnosed as pilomatricoma (n = 1), basaloid neoplasm (n = 1), and benign skin adnexal tumor (n = 1).…”

Warthin’s Tumor of the Parotid Gland With Degeneration to Diffuse Large B-cell Lymphoma: A Case Report and Review of Literature

“…Even excisional biopsy [1], despite being more invasive, is preferred, with a sensitivity and specificity of 98% and 99%, respectively [11]. The involvement of the salivary gland as the first clinical manifestation of the disease, the histological evidence that the lymphoma affects the parenchyma of the salivary glands, and the architectural and cytological confirmation of malignant character make suspect that this is a primary neoplasm of the parotid gland [3,8] as in the case of our patient, where the first manifestation was the increase in the volume of the parotid gland and the histopathological confirmation was similar to the previously mentioned criteria.…”

“…Primary salivary gland lymphomas account for 4.7% to 5% of extranodal lymphomas [ 2 ]. Between 70-80% of these malignant salivary gland tumors involve the parotid gland [ 1 , 3 ], followed by the submandibular gland at 18% [ 1 ]. Primary lymphomas of the parotid gland account for 1%-4% of parotid tumors [ 1 , 4 , 5 ].…”

“…Degeneration of WT to lymphoma has been documented only as an isolated case report, and there are no more than 30 cases in the literature [ 6 , 7 ]. Clinically, it can be indistinguishable from other gland tumors, which delays diagnosis and worsens the prognosis [ 3 ], but with proper management, it has a good prognosis [ 5 ].…”