Aggressive Primary Cutaneous Diffuse Large B-cell Lymphoma in the Scalp and Abdominal Wall: Unusual Presentation in a Middle-Aged Male

Abstract Primary cutaneous B-cell lymphomas are a heterogeneous group of extranodal B-cell non-Hodgkin lymphomas. We report the clinical presentation of a 43-year-old Saudi male who presented with a gradually enlarging abdominal wall and scalp nodules for 2-year duration. This presentation exemplifies a rare diagnosis of primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL-LT), manifesting in atypical anatomical sites beyond the lower limbs. The clinical scenario highlights the importance of maintaining a high index of suspicion for cutaneous lymphomas in patients with soft-tissue nodules, even in the absence of classic risk factors. This report emphasises the uncommon nature of PCDLBCL-LT, not only due to its overall rarity but also because of its unusual manifestation in the anatomical regions beyond the typical lower limbs. Moreover, the case is of particular interest given the patient’s demographic profile as a middle-aged male.