A Perplexing Case of Recurrent Abscess-Like Lesions: Insights Into Primary Cutaneous Diffuse Large B-Cell Lymphoma, Leg Type.

Primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL-LT) is one of the rarest forms of primary cutaneous lymphomas (PCLs) and it confers a poor prognosis. Diagnosis of PCDLBCL-LT can be challenging and complex as it can manifest with a myriad of dermatological presentations. However, early treatment with chemo-radiation leads to an appropriate response. We present the case of a 66-year-old female with a history of polymyositis and interstitial lung disease on immunosuppression who presented to our institution with recurrent abscess-like lesions localized to buttocks that were later biopsied and diagnosed as the leg-type variant of PCL. She received chemotherapy with the rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) regimen and subsequent involved-site radiation therapy (ISRT), which resulted in complete remission. The patient was later followed up and remained in remission for years.