lewis-x-antigen and Sarcoma--Myeloid

To study the clinicopathologic features, diagnosis and differential diagnosis of extramedullary infiltration of acute monocytic leukemia/monoblastic sarcoma.. Five cases of extramedullary infiltration of acute monocytic leukemia/monoblastic sarcoma were selected from 102 cases of myeloid sarcoma diagnosed during the period from 1990 to 2006. The clinicopathologic findings and followup data were retrospectively analyzed. Immunohistochemical study was also carried out with SP method.. Among the 5 cases studied, 3 were males and 2 were females, including 2 children and 3 adults. Generalized lymphadenopathy was found in 4 patients and skin lesions were observed in 2 patients. The tumor cells in all cases were positive for CD68 (KP1), CD68 (PGM1), lysozyme and CD45. They were negative for MPO, CD15, CD163, TdT, CD117, T and B cell markers. The Ki-67 index ranged from 40% to 80%. Follow-up data were available in all the 5 patients. Four of the 5 patients died of the disease, with the average survival time being 6.25 months.. Monoblastic sarcoma is a rare disease with poor prognosis. It is almost impossible to distinguish monoblastic sarcoma from granulocytic sarcoma and other types of small round cell tumors on the basis of morphologic examination alone. Immunohistochemistry is mandatory for a correct diagnosis.

Topics: Adult; Antigens, CD; Antigens, Differentiation, Myelomonocytic; Child; Diagnosis, Differential; Female; Humans; Immunohistochemistry; Immunophenotyping; Leukemia, Monocytic, Acute; Leukocyte Common Antigens; Lewis X Antigen; Male; Receptors, Cell Surface; Sarcoma; Sarcoma, Myeloid

To study the clinicopathologic features of myeloid sarcoma and to evaluate the role of immunohistochemical study in diagnosis of this entity.. Eighty-two cases of myeloid sarcoma were retrieved from the archives of Department of Pathology, West China Hospital of Sichuan University during the period from January, 1990 to February, 2005. The morphologic features were reviewed and classified according to the 2001 WHO classification for hematopoietic and lymphoid tissue tumors. Immunohistochemical study using a panel of 11 antibodies was performed on 73 cases. The survival data were collected and analyzed by SPSS 10.0.. The median age of patients was 35.5 years. The male-to-female ratio was 1.4:1. The sites of occurrence included lymph node (43.1%), skin (16.7%), nose (7.8%), soft tissue (7.8%) and bone (6.9%). Fifty-one cases (62.2%) represented myeloid sarcoma associated with an underlying myeloproliferative disorder and 25 cases (30.5%) represented solitary myeloid sarcoma. As for the morphology, 79 cases (96.3%) were granulocytic sarcoma, including 41 cases (51.9%) blastic type, 25 cases (31.6%) immature type and 13 cases (16.5%) differentiated type. The other 3 cases (3.7%) were monoblastic sarcoma. Immature eosinophils were found in 51 cases (64.6%) of granulocytic sarcoma, among which 13 cases (31.7%) were of blastic type. Immunohistochemical study showed that 95.9% cases (70/73) were positive for myeloperoxidase, 95.5% (63/66) for lysozyme, 95.2% (60/63) for CD68 (KP1), 90.8% (59/65) for leukocyte common antigen, 85.7% (54/63) for CD43, 77.8% (49/63) for CD117, 58.7% (37/63) for CD99, 54.0% (34/63) for CD15, 22.2% (14/63) for CD34, and 4.7% (3/64) for CD68 (PG-M1). Proliferation index, as demonstrated by Ki-67 positivity, was 0.49+/-0.22. Follow-up data was obtained in 59 of the 82 patients. The two- and five-year survival rates were 36.1% and 17.3% respectively. No significant prognostic factors were found in the survival analysis.. Myeloid sarcoma may precede, develop in a background of myeloproliferative disorder or even after remission of the disease. The presence of immature eosinophils is an important morphologic clue and immunohistochemical study plays an essential role in arriving at a correct diagnosis. Immunopositivity for myeloperoxidase is specific for granulocytic differentiation, while CD68 (PG-M1)-positivity suggests monocytic differentiation. Detailed clinicopathologic correlation is also helpful.

Topics: 12E7 Antigen; Adolescent; Adult; Aged; Antigens, CD; Antigens, CD34; Antigens, Differentiation, Myelomonocytic; Cell Adhesion Molecules; Child; Child, Preschool; Diagnosis, Differential; Female; Follow-Up Studies; Humans; Immunohistochemistry; Kaplan-Meier Estimate; Ki-67 Antigen; Leukosialin; Lewis X Antigen; Male; Middle Aged; Peroxidase; Proto-Oncogene Proteins c-kit; Sarcoma, Myeloid; Young Adult

We report a case of myeloid sarcoma of the brain mimicking a meningioma on CT scan. The lesion was first morphologically misdiagnosed as a lymphoma, but correctly identified by using immunochemistry with anti-myeloperoxidase, anti-CD68, anti-CD15 antibodies. An acute myeloid leukemia was diagnosed 5 months later. Myeloid sarcoma is frequently mistaken for malignant lymphoma, especially when it presents without leukemic manifestation, even at immunohistochemistry, since both express some leukocyte antigens. Careful evaluation of morphology for evidence of myeloid differentiation, and immunohistochemistry using anti-myeloperoxidase, anti-lysozyme, CD15, CD68 antibodies, should be used to confirm the diagnosis and to rule out lymphoma since the treatment is different.

Topics: Adult; Antigens, CD; Antigens, Differentiation, Myelomonocytic; Brain Neoplasms; Diagnosis, Differential; Humans; Immunohistochemistry; Leukemia, Myeloid, Acute; Lewis X Antigen; Male; Peroxidase; Sarcoma, Myeloid; Tomography, X-Ray Computed