LAUSR

Dear Editor, Peristomal malignancies are rare and difficult to diagnose. In the existing literature, there have only been two cases of peristomal cutaneous lymphoma reported, with only a handful of cases of lymphomas arising from the ileostomy mucosa itself. Due to its rarity, diagnosis is difficult as it mimicks other conditions, and there is no evidence base for its management. In this case, we present an unusual case of peristomal B cell lymphoma detected four decades after initial surgery. We present a 61-year-old male who had a total colectomy and end ileostomy for refractory ulcerative colitis when he was 17 years old. He had a completion proctectomy 8 years later. He had no major issues with the stoma for over four decades until he started developing irritation and erythema peristomally, which was initially thought to be contact dermatitis associated with leakage of stomal contents. However, he developed ongoing severe pain around his ileostomy until he was unable to stand upright due to the pain. He was reviewed at our stoma therapy clinic. He had welldemarcated deep ulcers and mucocutaneous separation peristomally with satellite rash-like lesions in a circumferential stellate appearance. The ulcers were thought to be associated with either extra-intestinal manifestations of inflammatory bowel disease such as peristomal pyoderma gangrenosum or severe contact dermatitis. There was no clinical evidence of cellulitis, necrosis or pustules and the patient did not have any septic complications. While biopsies are not essential in making the diagnosis of PPG or contact dermatitis (as results of biopsies are usually non-specific), a biopsy was performed to verify the diagnosis as the appearance of the peristomal changes in this case was unusual. Unexpectedly, the biopsy revealed that the patient had peristomal B cell lymphoma. He subsequently underwent six full cycles of chemotherapy (rituximab, cyclophosphamide, doxorubicin, oncovin, prednisolone (R CHOP) regimen) and two extra cycles of rituximab. The chemotherapy relieved the pain and irritation considerably but he had two readmissions to hospital with pneumonia and severe dehydration, and over the course of the chemotherapy, he lost 20 kg. There have only been two other reports of peristomal cutaneous lymphoma associatedwith ileostomy [1, 2]. In one case, a 54-year-oldmanwas diagnosed with peristomal cutaneous T cell lymphoma. In the other, a 73-year-old man with acquired immune deficiency syndrome (AIDS) developed a high grade non-Hodgkin’s lymphoma with diffuse proliferation into the dermis on the cutaneous side and the muscularis propria on the ileal side. Lymphoma within the ileostomy itself is also rare with only a handful of case reports [3, 4]. There have also been reports of lymphoma arising in ileal conduits [3]. In these case reports, there was not a consensus on standard treatment, with two undergoing chemotherapy, two having resections and another undergoing both chemotherapy and resection.With such limited cases, Chang et al. recommended treatment of stomarelated lymphomas to be extrapolated from treatment of sporadic intestinal lymphomas [4]. In this case, the peristomal ulceration healed completely with chemotherapy. However, the patient went on to develop recurrence of disease in the tonsils, thyroid, and lung. * James W.T. Toh [email protected]