Nomenclature: Leukemia and lymphoma
MC on the boards: Auer rod from myeloblast, and hypersegmented neutrophil from B12 and folate
A. Leukemia = malignancy of stem cells in the BM, and they can metastasize (like all cancer) and to
lymph nodes, leading to generalized lymphadenopathy and hepatosplenomegaly. Derived from
stem cells in the marrow and metastasize.
B. Malignant lymphoma: arise from LYMPH nodes, and can metastasize anywhere, include BM.
The MC site in body for lymphoma NOT developing in lymph node: stomach
Most extranodal (outside lymph node) primary lymphomas occur in the stomach;
H. pylori can produce these.
2 MCC location (lymphoid organ in the GI tract) = Payer’s patches (located in the terminal
MC lymphoma = follicular B cell lymphoma. This is an example of knocking off apoptosis gene -
14:18 translocation of a heavy chain; when you get the translocation, B cells will make bcl-2,
which inactivates apoptotic gene in the B cell, therefore, the apoptotic gene is immortal, leads
Nomenclature of Trophoblastic Tumors
A. Hydatidiform mole, presents with cluster of grapes. It manifests in the first trimester with signs of
preeclampsia (HP, proteinuria, edema in the first trimester). On ultrasound, will see uterus too large
for its gestational age, with a snowstorm appearance = classic complete mole; and can progress to
B. Choriocarcinoma mole is a benign tumor of the chorionic villus; chorionic villi are lined with
trophoblastic cells, including synctiotrophoblast on the outside (has contact with the blood, from
which O i2 extracted); under the synctiotrophoblast is the cytotrophoblast, then have warten’s jelly
in the chorionic villus, then have vessel that becomes the umbilical vein, which has the most O in2
the vessels of the fetus.
So, hydatidiform mole is a B9 tumor of the WHOLE chorionic villus, and it looks like grapes b/c it’s
dilated up. Choriocarcinoma is a malignancy of the lining of the chorionic villus: the
synctiotrophoblast and the cytotrophoblast (not the actual chorionic villus). Which makes
hormones? The syncytiotrophoblast synthesizes B-HCG and human placental lactogen (growth
hormone of pregnancy – it gives aa’s and glucose from mom to baby). So, when gestationally
derived, and even when they metastasize to the lungs, they respond well to chemotherapy
(methotrexate, chlabucil). Therefore, these are highly malignant tumors, but go away with
Things that end in “–oma”:
Everything that end in –oma is not necessarily b9 – ie melanoma (malignant tumor of melanocytes),
lymphoma (malignant tumor of lymph nodes) Also, all that ends in –oma is not necessarily a neoplasm – ie hemartoma = overgrowth of tissue that
is normally present in that area. Example: A bronchial hemartoma seen lung which is b9 cartilage
and a solitary coin lesion is seen in lung (also wonder if it’s a granuloma). The polyp in Peutz Jeghers
syndrome is a hemartoma (not even a neoplasm), that’s why there is no increase in risk of poly
cancer. Hyperplastic polyp (MC polyp in GI) is a hemartoma, it’s a B9 tissue in place it is not suppose
to be (ie pancreatic tissue in the stomach) – this is called a choristoma, or heterotopic ret.
MC complication of Meckel’s Diverticulum = bleeding from a gastric mucosa that is ulcerated, or
pancreatic tissue that is ulcerated. Should gastric mucosa be in the meckel’s diverticulum? No, b/c it
is in the small bowel (about 2 ft from the ileocecal valve). Hemartomas are non-neoplastic, and
therefore do not have cancer producing potential.
Increased mitotic rate does not mean cancer. What makes mitosis malignant is having an atypical
mitotic spindle (they are aneuploid and have more than the normal 46 c’somes). Key thing that
determines if it is malignant is its ability to metastasize. Malignant cells usually have a longer cell
cycle than the cells t