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| | Myeloid sarcoma [1, 11–13] | Carcinoid [14] | Lymphoma [15] | GIST [16] |
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| General characteristics | Extramedullary involvement | Indolent tumor that originate in cells of the neuroendocrine system that may produce hormones | Hodgkin’s and Non-Hodgkin varieties involving lymphocytes of B, T, or NK cell lineage | Submucosal mesenchymal neoplasms of the GIT |
| Incidence (cases/million persons/year) | 2 (adults)
0.7 (children) | 20 | Hodgkin 12 (<20 yrs)
NHL
19 (female 20–24)
29 (male 20–24)
390 (female 60–64)
547 (male 60–64) | 10–20 |
| Male : female ratio | 2 : 1 | No preference | NHL−1.4 : 1, ratio varies with subtype | No clear preference although some studies indicate higher male incidence |
| Anatomic location | Skin, soft tissues, bone, lymph nodes, orbits, and CNS. | Multiple locations. GI carcinoids found in appendix, small intestine, rectum, colon, gallbladder, and kidney | Lymph nodes. Extranodal sites: skin, brain, bowel, bone, and thymus | 50%–70% stomach, 20%–30% small intestine, 5%–15% colon/rectum, esophagus (<5%), rare in omentum and mesentery |
| Symptoms at presentation | Dependent on location of tumor. GI symptoms may range from nonspecific to jaundice or obstruction | Duodenal carcinoids may present with nausea, vomiting, abdominal pain, and hemorrhage due to excess gastrin production | Palpable painless lymph nodes, chest pain, constitutional (B) symptoms, and fatigue | Asymptomatic or nonspecific abdominal symptoms such as obstruction, appendicitis-like pain, and acute abdomen due to tumor rupture. |
| Pathology | Diffuse and infiltrative population of myeloblasts and granulocytes. The neoplastic cells usually contain scant cytoplasm with large round-oval nuclei | Firm white, yellow, or gray nodules.
Neuroendocrine cells have uniform nuclei and abundant granular or faintly staining (clear) cytoplasm | Hodgkin: Reed-Sternberg cells
NHL: varies depending on type | Range from slow growing, indolent to aggressive malignant cancers |
| Immunohistochemistry | MPO, CD34, CD117, CD68, and lysozyme | No specific IHC. May test for levels of 5-HIAA, CgA | Varies depending on type: CD30, CD15, CD5, CD10, and TdT | CD117, CD34 |
| Prognosis | The median survival of MS patients without AML has been reported to be 36 months, while those progressed to AML have a poor prognosis with median survival between 6 and 14 months | Dependent on site, size, and anatomical extent of disease.
Expression of Ki-67 and p53 may be associated with poor prognosis | 5-year survival ranges from 60%–82% depending on stage and type | Important factors are size of tumor and mitotic rate, average 5 yr survival 30%–60%. Duodenal GIST, 2 cm low risk >10 cm high risk. Mitotic risk >5 per 50 hpf |
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