Possible Pathologic Evaluation of Biopsy Specimens from Patients with Metastatic Cancer of Unknown Primary Site
| Evaluation/Findings | Suggested Primary Site or Neoplasm |
|---|---|
| Histology (hematoxylin and eosin staining) | |
| Psammoma bodies, papillary configuration | Ovary, thyroid |
| Signet ring cells | Stomach |
| Immunohistology | |
| Leukocyte common antigen (LCA, CD45) | Lymphoid neoplasm |
| Leu-M1 | Hodgkin's disease |
| Epithelial membrane antigen | Carcinoma |
| Cytokeratin | Carcinoma |
| CEA | Carcinoma |
| HMB45 | Melanoma |
| Desmin | Sarcoma |
| Thyroglobulin | Thyroid carcinoma |
| Calcitonin | Medullary carcinoma of the thyroid |
| Myoglobin | Rhabdomyosarcoma |
| PSA/prostatic acid phosphatase | Prostate |
| AFP | Liver, stomach, germ cell |
| Placental alkaline phosphatase | Germ cell |
| β-human chorionic gonadotropin | Germ cell |
| B, T cell markers | Lymphoid neoplasm |
| S-100 protein | Neuroendocrine tumor, melanoma |
| Gross cystic fluid protein | Breast, sweat gland |
| Estrogen and progesterone receptors | Breast |
| Factor VIII | Kaposi's sarcoma, angiosarcoma |
| Thyroid transcription factor 1 (TTF-1) | Lung adenocarcinoma, thyroid |
| Calretinin, mesothelin | Mesothelioma |
| URO-III, thrombomodulin | Bladder |
| Flow Cytometry | |
| B, T cell markers | Lymphoid neoplasm |
| Ultrastructure | |
| Actin-myosin filaments | Rhabdomyosarcoma |
| Secretory granules | Neuroendocrine tumors |
| Desmosomes | Carcinoma |
| Premelanosomes | Melanoma |
| Cytogenetics | |
| Isochromosome 12p; 12q(-) | Germ cell |
| t(11;22) | Ewing's sarcoma, primitive neuroectodermal tumor |
| t(8;14)a | Lymphoid neoplasm |
| 3p(-) | Small cell lung carcinoma; 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 |
| Receptor Analysis | |
| Estrogen/progesterone receptor | Breast |
| Molecular Biologic Studies | |
| Immunoglobulin, bcl-2, T cell receptor gene rearrangement | Lymphoid neoplasm |
aOr any other rearrangement involving an antigen-receptor gene.
Abbreviations: AFP, α-fetoprotein; CEA, carcinoembryonic antigen; PSA, prostate-specific antigen.