Relapse of acute myeloid leukemia manifested by cholecystitis: A case report and review of the literature

INTRODUCTION: AML is the most common form of leukemia in adults. In rare circumstances AML may present in the form of extra-medullary disease. Gallbladder infiltration with myeloblasts is rare and only a few cases exist in the literature describing this entity. PRESENTATION OF CASE: We present a rare case of AML relapse in the form of extramedullary infiltration of the gallbladder in a 50-year-old male patient. The leukemic infiltration presented as symptomatic cholecystitis and sepsis. A laparoscopic cholecystectomy was performed and the gallbladder was pathologically examined. Histopathologic examination demonstrated multiple scattered, highly atypical single cells admixed with some plasma cells, small lymphocytes and macrophages consistent with leukemic infiltration. The abnormal cells demonstrated immunohistochemical staining for CD68, CD33 and CD117. The patient did well post-operatively but the relapse precluded him from bone marrow transplantation. DISCUSSION: Although AML is relatively common, 3 cases per 100,000 population, extramedullary disease in the form of gallbladder infiltration is exceedingly rare. An extensive review of the literature revealed only four cases of myeloid infiltration of the gallbladder. To our knowledge this is the only case of relapsing disease in the form of gallbladder infiltration presenting as symptomatic cholecystitis in a pre-bone marrow transplantation patient. CONCLUSION: This case highlights the importance of maintaining a high index of suspicion of atypical manifestations of AML when managing refractory sepsis. Extramedullary manifestations of AML in the form of gallbladder infiltration must be considered in the differential diagnosis of patients with a history of myeloid malignancies and for patients whom fail conventional non-operative management.