Sarcoidosis Masquerading as Breast Implant- Associated Anaplastic Large Cell Lymphoma -  The Importance of Definitive Pathology to Guide Therapy.

[INTRODUCTION] Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is a rare critical outcome of breast implantation that typically presents 8 to 10 years after textured-implant placement with periprosthetic seroma. Treatment consists of implant removal and capsulectomy, which is typically curative. But in rare case, malignant infiltration through the capsule results in disseminated disease, necessitating aggressive treatment with systemic chemotherapy. Sarcoidosis, a chronic systemic granulomatous disease characterized by noncaseating granulomas, is another rare cause of periprosthetic seroma.

[CASE PRESENTATION] A 61-year-old female with a history of invasive ductal carcinoma of the breast status post textured implant-based reconstruction presented with late periprosthetic seroma and overlying rash. Cytology of seroma aspirate was suggestive of BIA-ALCL, and positron emission tomography-computed tomography was concerning for invasive disease. Surgical specimen pathology of the implant-capsule complex and skin punch biopsy of the overlying rash revealed only granulomatous inflammation. The patient was diagnosed with sarcoidosis and spared systemic chemotherapy treatment for disseminated BIA-ALCL.

[CONCLUSIONS] BIA-ALCL should be ruled out in all cases of late periprosthetic seroma. Definitive surgical pathology is necessary to prevent misdiagnosis and inappropriate treatment of masquerading entities, such as sarcoidosis.