These cells can develop into a frankly malignant tumor known as yolk sac tumor or endodermal sinus tumor. Adequate follow-up requires close observation, involving repeated physical examination, scanning (ultrasound, MRI, or CT), and measurement of AFP and/or βhCG. Epidemiology
Embryonal teratomas most commonly occur in the sacrococcygeal region; sacrococcygeal teratoma is the single most common tumor found in newborn humans. Of teratomas on the skull sutures, about 50% are found in or adjacent to the orbit. Limbal dermoid is a choristoma, not a teratoma. Teratoma qualifies as a rare disease, but is not extremely rare. Sacrococcygeal teratoma alone is diagnosed at birth in one out of 40,000 humans. Given the current human population and birth rate, this equals five per day or 1800 per year. Add to that number sacrococcygeal teratomas diagnosed later in life, and teratomas in other locales, and the incidence approaches 10,000 new diagnoses of teratoma per year. Other animals
Ovarian teratomas have been reported in mares,mountain lions, and canines. Teratomas also occur, rarely, in other species. Use in stem cell research
Pluripotent stem cells including human induced pluripotent stem cells have a unique property of being able to generate teratomas when injected in rodents in the research laboratory. For this reason, the so-called "teratoma assay" is one of the gold-standard validation assays for pluripotent stem cells.
Acute monocytic leukemia (AMoL, or AML-M5) is a type of acute myeloid leukemia. In AML-M5 >80% of the leukemic cells are of monocytic lineage. This cancer is characterized by a dominance of monocytes in the bone marrow. There is an overproduction of monocytes that the body does not need in the periphery. These overproduced monocytes interfere with normal immune cell production which causes many health complications for the infected individual. Causes
The pathology of AML involves abnormal proliferation and differentiation of a population of myeloid stem cells. Genetic mutations are identified in the majority of cases. A common genetic mutation identified in these cases are characterized as chromosomal translocations where information from one chromosome is exchanged to a non-homologous chromosome creating an unusual rearrangement of chromosomes. This translocation is often abbreviated as t(#of one chromosome involved, #of other chromosome involved). M5 is associated with characteristic chromosomal abnormalities, often involving chromosome 11, such as t(9;11), affecting the MLL (KMTA2) locus at 11q23; however MLL translocations are also found in other leukemia subtypes. The t(8;16) translocation in AMoL is associated with hemophagocytosis. These translocations yield the formation of chimeric proteins (RUNX1-RUNX1T1 and PML-RARA, respectively) which disrupt normal myeloid precursor development. Secondary leukaemia, which may include AML-M5, has been associated with exposure to epipodophyllotoxins, such as etoposide.Many cases of AML-M5 are seen to have enhanced phosphorylation of the STAT3 protein due to increased induction of cytokines thus increasing cell proliferation and survival.