Paraneoplastic syndromes
Cushing Syndrome ACTH-like substance Lung small cell anaplastic (oat cell) carcinoma
Hypercalcemia Parathormone-like substance Lung (squamous cell) carcinoma
Hyponatremia Inappropriate ADH secretion Lung small cell anaplastic (oat cell) carcinoma
Polycythemia Erythropoietin-like substance Renal cell carcinoma
Trousseau Syndrome Hypercoagulable state Various carcinomas
Hypoglycemia Insulin-like substance Various carcinomas and sarcomas
Carcinoid Syndrome 5-hydroxy-indoleacetic acid (5-HIAA) Metastatic malignant carcinoid tumors
A paraneoplastic syndrome occurs when a neoplasm elaborates a substance that results in an effect that is not directly related to growth, invasion, or metastasis of the tumor itself. Most paraneoplastic syndromes result from elaboration of hormone-like substances by the neoplastic cells, but a variety of effects are possible. Sometimes the appearance of the paraneoplastic syndrome may precede diagnosis of the neoplasm and may give a clue to its presence.