Management of bronchial carcinoid: An anaesthetic challenge

Shifting Paradigms in the Pathophysiology and Treatment of Carcinoid Crisis

Carcinoid crisis is a potentially fatal condition characterized by various symptoms, including hemodynamic instability, flushing, and diarrhea. The incidence of carcinoid crisis is unknown, in part due to inconsistency in definitions across studies. Triggers of carcinoid crisis include general anesthesia and surgical procedures, but drug-induced and spontaneous cases have also been reported. Patients with neuroendocrine tumors (NETs) and carcinoid syndrome are at risk for carcinoid crisis. The pathophysiology of carcinoid crisis has been attributed to secretion of bioactive substances, such as serotonin, histamine, bradykinin, and kallikrein by NETs. The somatostatin analog octreotide has been considered the standard of care for carcinoid crisis due to its inhibitory effect on hormone release and relatively fast resolution of carcinoid crisis symptoms in several case studies. However, octreotide's efficacy in the treatment of carcinoid crisis has been questioned. This is due to a lack of a common definition for carcinoid crisis, the heterogeneity in clinical presentation, the paucity of prospective studies assessing octreotide efficacy in carcinoid crisis, and the lack of understanding of the pathophysiology of carcinoid crisis. These issues challenge the classical physiologic model of carcinoid crisis and its common etiology with carcinoid syndrome and raise questions regarding the utility of somatostatin analogs in its treatment. As surgical procedures and invasive liver-directed therapies remain important treatment modalities in patients with NETs, the pathophysiology of carcinoid crisis, potential benefits of octreotide, and efficacy of alternative treatment modalities must be studied prospectively to develop an effective evidence-based treatment strategy for carcinoid crisis.

Paraneoplastic Syndromes in Lung Cancers: Manifestations of Ectopic Endocrinological Syndromes and Neurologic Syndromes

Paraneoplastic syndromes are clinical entities associated with cancers and often overlap with metabolic and endocrine syndromes. The cell types of lung cancer involved are frequently small cell, squamous cell, adenocarcinoma, large cell, and carcinoid tumor. A number of neurologic paraneoplastic syndromes have been described for which the tumor product remains unknown. These include peripheral neuropathies, a myasthenia-like syndrome, and subacute cerebellar degeneration. Although all of these syndromes may improve with successful treatment of the primary tumor, complete resolution is rare.