INTRODUCTION
Severe neutropenia and immunodeficiency, as either sequelae of hematologic malignancies or direct consequences of chemotherapy or hematopoietic cell transplant (HCT), increase the risk of infectious complications. Gastrointestinal infections observed in this patient population account for approximately 30% of neutropenic infections [1]. Mortality secondary to gastrointestinal infections in neutropenic patients has only been reported in two single-institution reviews but is consistent at 13% and 14% [1, 2]. The incidence of acute appendicitis in the pediatric population with acute leukemia or lymphoma is approximately 1.5% [3], however, the incidence is unknown for adults with hematologic malignancies or HCT patients. Acute appendicitis is, indeed, scarcely mentioned in hematopoietic cell transplant literature [1, 4, 5]. Though uncommon, appendiceal disease is a challenging diagnostic and therapeutic problem. These patients may be afflicted with alternative diseases such as mucositis, acute GVHD of the gastrointestinal tract, neutropenic enterocolitis (typhlitis), or infectious colitis, which confounds the diagnosis. Additionally, patients may be in various stages of hematologic recovery either in the pre-transplant or pre-engraftment period and may be on additional immunosuppression for prophylaxis or treatment of graft-vs-host disease (GVHD). This can lead to atypical, non-localized pain and/or lack of peritoneal signs which may delay diagnosis. The attenuated clinical findings were apparent in one pediatric study and resulted in a 37.5% error rate in accurate diagnosis of appendicitis [6]. These factors make it difficult to pursue invasive management given higher risk of surgical complications. Medical treatment and surgical intervention have been described in hematologic malignancies [3, 6] and hematopoietic cell transplant [2, 4, 5] but the lack of evidence makes management challenging. We report here on five adult hematopoietic cell transplant patients treated in our institution who developed appendiceal disease at various times in their clinical course.