- © 2005 by American Society of Clinical Oncology
Unusual Leukemia Presentations
CASE 2. Granulocytic Sarcoma of the Colon
A 50-year-old African American woman presented with a 2-week history of right lower quadrant abdominal pain that was exacerbated 3 days before admission and accompanied by fever and melena. Physical examination revealed a firm, distended abdomen with hypoactive bowel sounds, rebound tenderness, and guarding. There was no hepatosplenomegaly, lymphadenopathy, gingival hypertrophy, or mucocutaneous petechiae. The patient's vitals signs on admission were as follows: body temperature 101.1°F; pulse, 89/minute; respiration, 18/minute; and blood pressure, 148/84 mm/Hg. Laboratory data revealed a WBC of 89 × 109/L, with 51% neutrophils, 11% lymphocytes, 1% monocytes, and 37% circulating blasts; Hgb 10.1 g/dL; and platelets 83 × 109/L. A bone marrow aspirate was hypercellular but showed almost no erythropoiesis. There were 78% blasts that were intensely positive for myeloperoxidase, and 14% mature granulocytes, 1% eosinophils, 1% plasma cells, and 6% lymphocytes. Flow cytometry performed on the bone marrow revealed a blast population that expressed CD13, CD11c, CD33, CD38, and HLA-DR. Cytogenetics revealed a normal 46, XX karyotype. A diagnosis of acute myeloid leukemia (AML) with maturation was rendered. A computed tomography (CT) scan of the abdomen and pelvis revealed marked thickening of the bowel wall, primarily involving the cecum and the right colon, consistent with typhlitis in the setting of AML (Fig 1 is a CT scan showing marked thickening of the cecum and right colon). Given the severity of presentation with the symptoms of acute abdomen, the patient underwent emergent right hemicolectomy with end ileostomy. The cecum showed an infiltrate of blasts (naphthol-ASD-chloroacetate esterase positive) in the mucosa, perivascularly, and throughout the bowel wall, consistent with granulocytic sarcoma (GS). (Fig 2: granulocytic sarcoma of the large intestine. A tumor composed of myeloid blasts and maturing granulocytes fills and expands the cecal wall; hematoxylin and eosin 20×. Fig 3: leukemic infiltrate in submucosa. Numerous blasts and some maturing granulocytes are seen in loose submucosal tissue of the colon; hematoxylin and eosin 400×.) There was also edema, acute inflammation, and leukemic infiltration of mesenteric lymph nodes. One week after surgery, the patient received induction chemotherapy with topotecan, cytarabine, and mitoxantrone. With the exception of the expected cytopenias, she tolerated this regimen well. She attained a remission and then underwent consolidation therapy with cytarabine and idarubicin. Her consolidation course was complicated by Candida glabrata fungemia, Klebsiella bacteremia, and an upper gastrointestinal hemorrhage secondary to telangiectasias in the stomach and duodenum. These complications were managed with the use of appropriate antimicrobials, packed RBCs, platelet transfusions, and proton-pump inhibitors. On recovery, a subsequent bone marrow examination showed no evidence of residual disease. Her abdominal wound healed well; 10 months later, the patient underwent end-to-end anastomosis. The patient continues to remain in complete remission at the time of last follow-up.
This case represents an unusual presentation of AML patient with GS of the right colon and symptoms of acute abdomen. GS (also called myeloid sarcoma by the WHO classification) is a localized tumor mass composed of immature cells of granulocytic series or cells of each maturation step in extramedullary sites.1,2 It was previously called chloroma after the greenish hue noted on exposure of the tissue to air,3 but was renamed granulocytic sarcoma by Rappaport. Although granulocytic sarcoma develops in 2% to 8% of patients with acute myeloid leukemia2,4,5 and can occur virtually anywhere in the body, the most common sites of involvement in patients with no evidence of overt leukemia are the bone, lymph nodes, and skin.5–7 Other organs may be involved, including the gastrointestinal tract, but involvement of the large bowel has only been reported in a few case reports.8–11 GS usually occurs concomitantly with or after the onset of AML.2,12 However, on rare occasions, it evolves before the onset of AML, and a misdiagnosis of lymphoma is frequently made.13 Diagnostic distinction from a high-grade non-Hodgkin's lymphoma, especially large cell lymphoma can be difficult in patients without bone marrow involvement.14 The diagnosis is aided by histochemical stains, especially napthol-ASD-chloroacetate esterase (NACE; Leder stain), or by immunoperoxidase staining with monoclonal antibodies for myeloperoxidase, lysozyme, or CD34 antigen.15 Flow cytometry or cytogenetic analysis of the specimen can be helpful. Immunophenotyping is more important in cases in which NACE staining is negative because of immaturity of the tumor cells. If there is no discernible hematologic abnormality at the time of diagnosis, and if treated with either surgery or local radiotherapy with no further systemic chemotherapy, up to 80% to 90% of patients develop AML at a mean of 11 months after the diagnosis of GS.2 But if patients are treated with aggressive chemotherapy with AML regimens, the projected 3-year survival is reported to be 30%.5
Authors' Disclosures of Potential Conflicts of Interest
The authors indicated no potential conflicts of interest.
