Which form of cancer is commonly associated with SIADH (Syndrome of Inappropriate Antidiuretic Hormone secretion)?

Small cell carcinoma of the lung is indeed the form of cancer most commonly associated with the Syndrome of Inappropriate Antidiuretic Hormone (SIADH) secretion. This association occurs due to the ectopic production of antidiuretic hormone (ADH) by tumor cells. Small cell lung cancer, being a neuroendocrine tumor, has the capacity to produce various hormones, including ADH and corticotropin, which can lead to paraneoplastic syndromes.

SIADH results in the retention of water, dilutional hyponatremia, and decreased serum osmolality, complicating the clinical picture in affected patients. The mechanism through which small cell carcinoma induces SIADH is a prime example of how certain tumors can cause systemic effects beyond local tumor growth.

While lung adenocarcinoma, non-small cell lung cancer, and mesothelioma can cause a variety of paraneoplastic syndromes, they are less commonly associated with SIADH compared to small cell carcinoma. This specificity helps clinicians in identifying potential paraneoplastic syndromes based on the type of malignancy present in a patient. Thus, recognizing small cell carcinoma's link to SIADH is crucial in clinical oncology and symptom management.