biopsy of metastatic cancer of unknown primary

Pathology: 1) histology (hematoxylin & eosin (H&E) staining a) psammoma bodies, papillary configuration - ovarian cancer - thyroid cancer b) signet ring cells - gastric cancer - colon cancer - breast cancer - ovarian tract - bladder cancer - prostate cancer 2) immunohistochemistry - leukocyte common antigen (CD45) -> lymphoid neoplasm - Leu-M1 -> Hodgkin's disease - epithelial membrane antigen -> carcinoma - cytokeratin intermediate filaments -> carcinoma - carcinoembryonic antigen (CEA) -> carcinoma - HMB45 -> melanoma - desmin -> sarcoma - thyroglobulin -> thyroid carcinoma - calcitonin -> medullary thyroid carcinoma - myoglobin -> rhabdomyosarcoma - prostate-specific antigen -> prostate cancer - prostatic acid phosphatase -> prostate cancer - alpha-fetoprotein (AFP) - liver cancer - gastric cancer - germ cell cancer - placental alkaline phosphatase -> germ cell cancer - B- & T-cell markers -> lymphoid neoplasm - S-100 protein - neuroendocrine tumor - melanoma - gross cystic fluid protein - breast cancer - sweat gland tumor - factor VIII - Kaposi's sarcoma - angiosarcoma 3) flow cytometry - T-cell markers -> lymphoid neoplasm 4) ultrastructure (electron microscopy) - actin-myosin filaments -> rhabdomyosarcoma - secretory granules -> neuroendocrine tumors - desmosomes -> carcinoma - premelanosomes -> melanoma 5) cytogenetics - isochromosome 12p; 12q(-) -> germ cell tumor - t(11;12) - Ewing's sarcoma - primitive neuroectodermal tumor - t(8;14) -> lymphoid neoplasm - 3p(-) - small cell carcinoma of the lung - renal cell carcinoma - mesothelioma - t(X;18) -> synovial sarcoma - t(12;16) -> myxoid liposarcoma - t(12;22) -> clear cell sarcoma (melanoma of soft parts) - t(2;13) -> alveolar rhabdomyosarcoma - 1p(-) -> neuroblastoma 6) receptor analysis - estrogen receptor -> breast cancer - progesterone receptor -> breast cancer 7) molecular biological studies - immunoglobulin gene rearrangement -> lymphoid neoplasm - bcl2 gene rearrangement -> B-cell neoplasm - T-cell receptor gene rearrangement -> T-cell neoplasm

References

Harrison's Principles of Internal Medicine, 14th ed. Fauci et al (eds), McGraw-Hill Inc. NY, 1998, pg 616