A 75 year old male presenting with fatigue and weight gain for 4-6 weeks.
75 year old Caucasian male with history of spinal cord injury and paraplegia, presented with fatigue and weight gain for 4-6 weeks. Examination showed blood pressure of 160/105, easy bruising, paraplegia and a normal cardiorespiratory examination.Initial potassium level was 2.3 mg/dl. It remained low despite potassium replacement. Random serum cortisol level was 112 mcg/dl. Serum aldosterone level was 4 ng/dl (N= <16). The plasma renin level measurement was 0.39 ng/ml/hr (N= 0.5-1.5). A low dose and high dose Dexamethasone suppression test failed to suppress the cortisol level that remained above 90 mcg/dl. Serum ACTH level was 1227 pg/ml (N=9-52 pg/ml. A chest, abdominal and pelvic CT revealed a 1.5 cm diameter subpleural density noted at the base of right middle lobe. Bilateral adrenal gland hyperplasia was noted. Pt underwent right middle lobe resection. A postoperative whole body octreotide scan was negative for abnormal uptake. A diagnosis was ectopic ACTH secreting subpleural carcinoid tumor was made.DISCUSSION: Pulmonary Carcinoid is a low-grade malignant neoplasm. Incidence is only 0.6- 2.4 % of all lung cancers. Mean age at diagnosis is 50. Incidence is higher in caucasians. The lesions can be central (80%) or peripheral (20%) including subpleural location. The etiology and pathogenesis of carcinoid tumors are unclear. There is no link with cigarette smoking or with most other agents known to be associated with pulmonary carcinoma. The initial presentation can be vague. Histopathology is similar in central and peripheral tumors showing neoplastic cells that are small, argyrophilic, often distinctly spindled, grouped in small nests with a somewhat whorled appearance.Treatment includes surgical resection of the lesion.
Pulmonary subpleural carcinoid is a rare tumor requiring a high index of suspicion for diagnosis.
J.F. Durrani, None.