Case report: nocardia infection associated with ectopic cushings

BACKGROUND Cushing's syndrome results from exposure to excess glucocorticoids. Ectopic Cushings is endogenous ACTH dependant form of Cushing's associated with markedly raised ACTH and cortisol levels. This leads to an impaired immune response, setting the stage for occurrence of opportunistic infections. Nocardiosis is a gram positive bacterial infection caused by aerobic actinomycetes in genus Nocardia. We report a series of patients diagnosed with ectopic Cushings, having pneumonia with Nocardia spp. In one of these cases, the manifestations of Cushing's disappeared with treatment for Nocardia. CASE PRESENTATION Two middle aged men of Asian descent presented to the Endocrine clinic: the first with history of exertional shortness of breath, and weight loss for 1 year, the other with facial swelling, disturbed sleep and lethargy for a month. The third case was a young Asian male who presented with progressive weakness & weight loss for 2 months. All three patients had uncontrolled hypertension, high blood sugars & were hypokalemic (K: 2.52, 2.9, 1.5 mmol/l); 24 hour urine cortisol was elevated at 2000, 27216 and 9088 (32-243 ug/24 hours); ACTH 68.5, 159, 255 [0-48 pg/ml), respectively. Their MRI pituitary was normal, inferior petrosal sinus sampling revealed no central peripheral gradient. CT chest of these subjects demonstrated cavitatory lung lesions; microscopic analysis of respiratory samples was suggestive of infection with Nocardia spp. Histopathology of bronchoscopic-guided biopsy revealed no malignancy. Antihypertensives, insulin, potassium replacement, ketoconazole & trimethoprim-sulphamethoxazole (TS) were initiated. The patients' symptomatology improved & cavitatory lesions resolved with treatment. The primary source for the ectopic cushings remained unknown. The first case required bilateral adrenalectomy. The second case followed a progressively downhill course leading to death. In the third case, we were able to completely taper off ketoconazole, potassium, insulin & antihypertensives, after starting TS. CONCLUSION Opportunistic infections are known to be associated with Cushing's syndrome, and higher levels of glucocorticoid secretion are found in patients with ectopically produced ACTH. Pulmonary nocardiosis is important differential to consider. This series includes the first case reported in which signs and symptoms of cushings subsided after treatment of Nocardia.