Atypical Presentation of Peripheral T-Cell Lymphoma as Cause of an Aggressive Primary Left Breast Malignancy

Introduction

Peripheral T-cell Lymphoma (PTCL) is a subtype of non-Hodgkin lymphoma that generally predominates in the lymph nodes and rarely involves the breasts. Here we present a case where PTCL not only involved the breast but is the primary cause of an aggressive breast cancer, an exceptional rarity with only a few cases ever reported.

Case presentation

A 76-year-old female with a history of diabetes mellitus, hypertension, hyperlipidemia, and blindness secondary to glaucoma was admitted after suffering a mechanical fall. Incidentally, patient endorsed left breast pain with malodorous, purulent discharge for the past 3 weeks. She had a similar episode two years ago, when a breast surgeon drained the lesion and was given a course of antibiotics. Mammogram obtained in 2021 displayed scattered areas of fibroglandular densities, without any suspicious masses, calcifications or other abnormalities. Physical exam revealed an indurated left breast mass without any active discharge. No focal neuro-deficits, lymphadenopathy, nor hepatosplenomegaly was appreciated. General surgery was consulted for an incision and drainage; however, no drainage was obtained. Breast surgery was then consulted for a biopsy, which revealed T cell markers (BETAF1, CD8, AND TIA1CD3, CD43, CD56, CD15, BCL2, GATA3, CD79a, C-MYC). Further work-up with non-contrast CT scan of head showed small bone lucencies throughout the skull; there were no abnormalities when compared to CT in 2016. MRI of the head revealed left clival expansile lytic lesion and scattered bilateral calvarial lytic enhancing masses without any brain involvement. CBC showed pancytopenia. In depth lab work eventually ruled out various other disorders including Multiple Myeloma, making the likely diagnosis of “Left Breast Peripheral T-cell lymphoma, not otherwise specified” with metastasis to the skull and infiltration of the bone marrow. After discussing the diagnosis and plan with the patient and her son, in collaboration with multiple sub-specialities taking care of the patient, patient decided to be placed in hospice care due to co-morbidities and age, insufficient data on treatment and prognosis, and aggressiveness of the PTCL. Patient refused any further workup and life-saving intervention.

Discussion

This case demonstrates the complexity of T-cell lymphoma and its diagnostic and clinical presentation. Breast involvement of PTCL is very rare and usually a manifestation of secondary course of the disease, rather than the primary cause. Patient’s course was already atypical for lymphoma, without obvious nodal or common extra-nodal site involvement; breast symptoms were incidental findings, unrelated to the chief complaint. Diagnosis was further confounded by lytic lesions of the skull and pancytopenia mimicking the presentation of Multiple Myeloma. As there are no specific characteristic immunophenotypes for PTCL, a lengthy work up was required to rule out other pathologies. By the time a diagnosis was confirmed, the patient refused treatment of this rapidly deteriorating disease.