A Case of Colonic ALK-Positive Anaplastic Large Cell Lymphoma

Abstract

Background: Primary colonic lymphoma is rare, comprising 0.2 - 1.2% of colonic malignancies1, the majority are cecal diffuse large b cell lymphoma. Gastric lymphoma is the most common gastrointestinal lymphoma followed by the small intestine. Anaplastic Large Cell Lymphoma (ALCL) is a peripheral T-Cell lymphoma divided into primary cutaneous or systemic. Systemic ALCL is further categorized by the presence of a surface protein Anaplastic Lymphoma Kinase (ALK). ALK positive ALCL denotes a better prognosis.3 Here we report a case of colonic ALK positive ALCL. Case Presentation: A previously well 23-year-old male presented with three weeks of non-bloody diarrhea, sweats, nausea and vomiting. Upon presentation to hospital, the patient was tachypnic and requiring O2. Physical examination revealed bibasilar crackles, his abdomen was tender throughout, he did not have hepatosplenomegaly, nor lymphadenopathy. He was admitted with presumed aspiration pneumonia secondary to gastroenteritis and started on empiric antibiotics. His WBC was 28 x 10ˆ9/L, lactate 3.3 mmol/L, CRP 421. CT showed multiple enlarged abdominal lymph nodes. He had positive EBNA serology in keeping with prior EBV infection. Colonoscopy showed small erosions and polypoid lesions in the transverse colon. He was transferred to a tertiary care center because of increasing O2 requirements and multi-organ failure requiring intubation, ECMO and dialysis. Pathology of the colonic polypoid lesion revealed ALK positive ALCL. CHOP chemotherapy began during his ICU stay, vincristine and doxorubicin were held because of deteriorating liver dysfunction. With treatment, his organ failure improved and within days he was extubated, dialysis and ECMO were stopped and he was transferred to the hematology ward where he continues with chemotherapy.Figure: Enhanced coronal CT scan demonstrating massive abdominal lymphadenopathy.Figure: Enhanced axial CT scan demonstrating massive abdominal lymphadenopathy.Figure: Enhanced sagittal CT scan demonstrating massive abdominal lymphadenopathy.Discussion: Lymphoma is an important diagnosis to consider when evaluating a patient with diarrhea and lymphadenopathy. Few cases report ALCL involving the gastric mucosa, most include the stomach in isolation or the colon.4,5,6 Despite active cancer being a relative contraindication to ECMO, the severity of this patient's presentation necessitated this intervention. There have been case series reporting the use of ECMO in patients with active hematologic malignancies, where ECMO preceded the diagnosis of malignancy7. This case illustrates the importance of a high index of suspicion for lymphoma given diffuse adenopathy and taking biopsies.