Case Presentation: 63-year-old woman with 80-pack year smoking history presented with right flank pain for two days and weight loss of 35lbs in 6 months. Chest X-ray as a part of the workup was found to have a mass like opacity in left lung. Subsequent CT scan of chest and abdomen/pelvis showed a left upper lobe mass of 115 x 65 x 61 mm with liver and bilateral adrenal metastasis. IR guided biopsy of the left liver lobe lesion showed high grade metastatic Neuroendocrine Tumor (NET). She was discharged with plan for palliative chemotherapy however in the interim she presented with watery diarrhea, flushing, wheezing and dyspnea for two weeks. Infectious work-up for diarrhea including clostridium difficle, stool ova/parasites, stool culture and cryptosporidium were negative. She was thought to be having functional NET and was started on octreotide 50mcg SQ q8hrs with improvement in her diarrhea. Transthoracic echocardiogram showed no valvular abnormalities. 5-HIAA levels in 24-hour urine sample was 7.1-mg/24 hrs (normal range <6mg/24hrs). The next day she became confused with fluctuating mental status. MRI brain under anesthesia ruled out leptomeningeal carcinomatosis. In the meantime, she was also started on chemotherapy with carboplatin, etoposide and dexamethasone. Five days after her chemotherapy she developed sudden onset of SOB with altered mental status, tachycardia, facial flushing and diffuse bilateral wheezing; was transferred to ICU for presumed carcinoid crisis and was given a bolus of octreotide 1000mcg IV followed by drip 50 mgm/hr titrated to a maximum of 200mcg/hr. Her blood serotonin levels were low (20 ng/ml) and chromogranin levels were mildly elevated (21ng/ml). Her ICU course was complicated with sepsis with unfortunate demise in the next few days.
Discussion: Lung neuroendocrine tumors (LNETs) accounts for 20-30 percent of all NETs. Carcinoid syndrome is caused by systemic release of serotonin and other vasoactive amines, seen less with LNETs than mid-gut NETs as they lack aromatic acid decarboxylase necessary for serotonin production. The frequency of carcinoid syndrome in lung NETs is 8% with localized disease as compared to 15 % with distant metastasis and when present, manifestations are usually prolonged and severe; with normal levels of urinary 5-HIAA and blood serotonin. They usually have very severe and prolonged flushing, lasting hours to days with disorientation, anxiety and tremors. The specific hormone responsible for these symptoms is unclear, it is thought to be histamine. Carcinoid crisis is a life-threatening form of the carcinoid syndrome that may be triggered by tumor manipulation (e.g. biopsy, surgery) or by anesthesia. Less commonly reported after hepatic arterial embolization, or radionuclide therapy, mostly in patients with extensive tumor bulk. Predominant symptom is wide blood pressure fluctuations with predominance of hypotension. Our patient with clinical features of carcinoid syndrome with normal levels of vasoactive amines, already on octreotide precipitated into carcinoid crisis from chemotherapy.
Conclusions: it is important for the clinicians to know this possible complication associated with surgery, anesthesia and chemotherapy which is under recognized with lung NETs. This should prompt them to treat prophylactically with octreotide infusion 12 hrs pre till 48-72 hrs post intervention.