High-Grade Non-Hodgkin Lymphoma, Diffuse Large B-Cell Lymphoma Type Masquerading as Thyroid Malignancy and Inflammatory Breast Carcinoma: A Case Report.

This case report describes a 75-year-old female who presented with generalized tiredness and neck swelling, initially raising suspicion of a primary thyroid malignancy. Fine-needle aspiration of the thyroid nodule was suspicious for malignancy (Bethesda Category V). Further evaluation revealed an inflammatory mass lesion in the right breast which was clinically diagnosed as inflammatory carcinoma and multiple enlarged lymph nodes including axillary, cervical, supraclavicular, and inguinal nodes. Immunocytochemistry on fine needle aspiration cytology (FNAC) and biopsies and immunohistochemistry of the breast lesion and lymph nodes in the patient ultimately revealed disseminated High-Grade Non-Hodgkin Lymphoma (NHL), Diffuse Large B-Cell Lymphoma (DLBCL) type. This case highlights the diagnostic challenges linked to atypical presentations of lymphoma mimicking other primary malignancies of solid organs.