Harrison's Internal Medicine Chapter 96. Paraneoplastic Syndromes: Endocrinologic/Hematologic Paraneoplastic Syndromes: Endocrinologic/Hematologic: Introduction In addition to local tissue invasion and metastasis, neoplastic cells can produce a variety of peptides that that can stimulate hormonal, hematologic, dermatologic, or neurologic responses. Paraneoplastic syndromes refer to the disorders that accompany benign or malignant tumors but are not directly related to mass effects or invasion. Tumors of neuroendocrine origin, such as small cell lung carcinoma (SCLC) and carcinoids, produce a wide array of peptide hormones and are common causes of paraneoplastic syndromes. . | Chapter 096. Paraneoplastic Syndromes Endocrinologic Hematologic Part 1 Harrison s Internal Medicine Chapter 96. Paraneoplastic Syndromes Endocrinologic Hematologic Paraneoplastic Syndromes Endocrinologic Hematologic Introduction In addition to local tissue invasion and metastasis neoplastic cells can produce a variety of peptides that that can stimulate hormonal hematologic dermatologic or neurologic responses. Paraneoplastic syndromes refer to the disorders that accompany benign or malignant tumors but are not directly related to mass effects or invasion. Tumors of neuroendocrine origin such as small cell lung carcinoma SCLC and carcinoids produce a wide array of peptide hormones and are common causes of paraneoplastic syndromes. However almost every type of malignancy has the potential to produce hormones or cytokines or to induce immunologic responses. Careful studies of the prevalence of paraneoplastic syndromes indicate that they are more common than is generally appreciated. The signs symptoms and metabolic alterations associated with paraneoplastic disorders may be overlooked in the context of a malignancy and its treatment. Consequently atypical clinical manifestations in a patient with cancer should prompt consideration of a paraneoplastic syndrome. The most common endocrinologic and hematologic syndromes associated with underlying neoplasia will be discussed here. Etiology Hormones can be produced from eutopic or ectopic sources. Eutopic refers to the expression of a hormone from its normal tissue of origin whereas ectopic refers to hormone production from an atypical tissue source. For example adrenocorticotropic hormone ACTH is expressed eutopically by the corticotrope cells of the anterior pituitary but it can be expressed ectopically in SCLC. Many hormones are produced at low levels from a wide array of tissues in addition to the classic endocrine source. Thus ectopic expression is often a quantitative change rather than an absolute change in tissue
