Primary Cutaneous Diffuse Large B-Cell Lymphoma–Leg Type Masquerading as a Mucocele

An 81-year-old woman with a history of breast cancer and hypothyroidism presented with an unusual case of Primary cutaneous diffuse large B-cell lymphoma–leg type (PCDLBCL-LT) on her upper lip, a condition typically found on the lower limbs and primarily affecting elderly females. Initially suspected to be a mucocele, a punch biopsy revealed atypical B-cells indicative of PCDLBCL-LT. The patient underwent three cycles of R-CHOP (rituximab, cyclophosphamide, vincristine, prednisone) and radiation therapy, resulting in no clinical evidence of disease. This case underscores the importance of timely recognition of PCDLBCL-LT, even in atypical presentations, due to its aggressive nature and potential impact on patient outcomes.