All posts by peferguson

Antibody List, G - M Antibodies

MOC-31

MOC-31 is a glycoprotein on the cell-membrane (epithelial glycoprotein 2/epithelial cell adhesion molecule – Ep-CAM) that is widely distributed on epithelial cells and tumor cells.  MOC-31 is often used to differentiate adenocarcinoma (93% positive) from mesothelioma (93% negative).  Other tumors also typically negative for MOC-31 include:  hepatocellular carcinoma (HCC), germ cell tumors, and renal cell (some report up to 50%+) carcinomas.  Some tumors may have characteristic staining patterns (e.g. membraneous vs. cytoplasmic or apical).

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PathMD Blog, Bone Marrow, WHO Classification

JAK2, CALR, & MPL Testing in Myeloproliferative Neoplasms (MPN)

Molecular Testing Specimen Adequacy Summary
  • JAK2, CALR, and MPL testing is often performed on peripheral blood specimens in an outpatient setting.
  • JAK2 mutations are preferably analyzed in granulocytes.
  • Peripheral blood and bone marrow specimens are equally adequate for the identification of JAK2 mutations.
  • By extrapolation, CALR and MPL testing on peripheral blood specimens should be equally adequate.

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Organ Systems, Lymph Node, WHO Classification

Extranodal Marginal Zone Lymphoma of Mucosal Associated Lymphoid Tissue (MALT Lymphoma)

Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) involves extra nodal tissue and shows infiltration of the marginal zones and inter follicular regions. 
  • Gastric MALT is associated with H. pylori infection in up to 90% of cases. 
  • MALT in the thyroid has been associated with Hashimoto’s thyroiditis (~20% of cases).
  • Ocular MALT lymphomas have been associated with various infections.

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Organ Systems, Lymph Node, WHO Classification

Plasmablastic Lymphoma

Immunophenotypic Expression Pattern
Marker
Comment
Negative
Weak/Negative
Weak/Negative
Negative
Positive
Variable
Positive (Usually)
Negative (Usually)
Positive
Rare + case
References
Parker, A., et. al.  “Best Practice in Lymphoma Diagnosis and Reporting.”  British Committee for Standards in Haematology, Royal College of Pathologists.  April, 2010.