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RESIDENT
CASE
STUDIES
September 25,
2003: Case 4 Table
of Contents | List
of Diagnoses | Case 1 | Case 2 |
Case
3 | Case 4 | Case
5
52 year old black male with acute abdomen
and cecal mass, ex lap to rule out appendicitis
Discussion by Toby Gray, MD
Acute myelocytic leukemia, FAB
classification M1, which is AML without maturation, involving the ileum
and cecum
Incidence: 10%
of AML is AML-M1
Distribution:
median age 45
Gross Appearance:
Leukemic infiltration of the bowel can cause multiple gross presentations
in including polypoid masses, plaquelike thickenings, ulcers, and/or
diffuse masses. The specimen in this case was erythematous with diffuse
thickening of the cecum.
Microscopic
Appearance:
- The leukemic cells are large,
pleomorphic, discohesive cells with high N/C ratios and little
cytoplasm infiltrating through the submucosa
- Myeloid lineage cells can have auer rods
present in the cytoplasm, although none are noted in this specimen.
Diagnostic Criteria
- Large, hematologic appearing discohesive
cells
- High N/C ratio with coarse chromatin
- Immunohistochemistry/Flow cytometry
Immunostains:
- CD 13, 33, 117 positive with +/-
myeloperoxidase staining
Cytogenetic and Molecular Techniques:
- No association with recurrent
chromosomal abnormalities
Differential Diagnosis:
- Leukemia
- Lymphoma
- Melanoma
- Infectious causes
References:
- Cotran: Robbins Pathologic Basis of Disease, 6th ed. 1999 W. B. Saunders Company.
- Jaffe,
E, et al. WHO Classification of Tumours: Pathology and Genetics of
Tumours of Haematopoietic and Lymphoid Tissues. 2001.
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