Perforated Ogilvie' syndrome. A rare paraneoplastic manifestation of small cell lung cancer secreting ACTH

BACKGROUND: Acute Colonic Pseudo-Obstruction (ACPO) is a clinical syndrome whose specific pattern is the acute dilation of the viscus without mechanical obstruction. Causes can be found in myopathies and neuropathies but often the syndrome is secondary to various metabolic, degenerative or endocrine disorders. Few paraneoplastic cases have been reported as well. CASE DESCRIPTION: A 59 years old woman, with a six months history of hypercortisolism, has been diagnosed with Small Cell Lung Carcinoma (SCLC) secreting ACTH. After the first cycle of chemotherapy the patient showed an acute intestinal obstructive syndrome. The CT scan showed an exceedingly dilated colon (cecum 13.9 cm and transverse colon 10 cm). The physical and laboratory findings led to laparotomy and perforations of both the cecum and the transverse colon were found. A subtotal colectomy with ileocolic anastomosis was performed. The patient was discharged on postoperative day 15. After a second cycle of chemotherapy she had further worsening and died 55 days after surgery. DISCUSSION: Small Cell Lung Carcinoma is frequently associated with paraneoplastic syndromes, related to ectopic endocrine activity or to immunologic changes. Autoimmune impairment and destruction of the myenteric plexus by antineuronal, anti-Calcium-Channel, anti Cajal-cell antibodies have been described in patients with SCLC. These alterations are usually the cause of gastrointestinal dysmotility in lung cancer patients. The electrolytic imbalance, typical of the endocrine syndromes, is also a known pathogenetic factor of Ogilvie' syndrome. Obstruction can respond to medical treatment or to colonoscopic decompression but recurrence are frequent and ischemia and perforation can develop. The prognosis is overall poor and in the presence of endocrine disfunctions, dismal. After perforation mortality rate further rises.