A Multidisciplinary Approach to the Diagnosis and Management of a Mammary Myofibroblastoma in a Male with a History of Diffuse Large B-Cell Lymphoma: A Case Report

Background: and Clinical Significance: Diffuse Large B-Cell Lymphoma (DLBCL) is a morphologically and molecularly heterogeneous lymphoproliferative disorder that originates from a clonal B-cell ancestor, that can either arise de novo or transform from an indolent B-cell lymphoma. It represents 30% of adult lymphoma cases. Patients usually present with rapidly enlarging lymph nodes or mass(es) at a single site or multiple sites. Myofibroblastoma (MFB) is a benign mesenchymal tumor of the mammary stroma composed of fibroblasts and myofibroblasts. These entities do not often present concurrently. Case presentation: An 80-year-old man with a history of Diffuse Large B-Cell Lymphoma (DLBCL) IV-BS stage with a high-risk International Prognostic Index (IPI). The patient underwent treatment with R-CHOP regimen. In the post therapeutic evaluation, an 18F‐Fluorodeoxyglucose (18F-FDG) positron emission tomography with computed tomography (PET‐CT) scan revealed a nodular solid lesion with a faintly increase metabolic standardized uptake value (SUVmax) of 3 in the upper outer quadrant of his left breast. The patient has not presented symptoms or any complications since surgery (12 months) and remains in complete remission (CR). Conclusions: Given the potential diagnostic pitfall and therapeutic implications of MFB in the context of DLBCL, a conscientious evaluation by a multidisciplinary team (MDT) is highly recommended.