Pseudo-pheochromocytoma due to obstructive sleep apnea: a case report

SUMMARY

Obstructive sleep apnea (OSA) is a condition of intermittent nocturnal upper airway obstruction. OSA increases sympathetic drive which may result in clinical and biochemical features suggestive of pheochromocytoma. We present the case of a 65-year-old male with a 2.9-cm left adrenal incidentaloma on CT, hypertension, symptoms of headache, anxiety and diaphoresis, and persistently elevated 24-h urine norepinephrine (initially 818 nmol/day (89-470)) and normetanephrine (initially 11.2 µmol/day (0.6-2.7)). He was started on prazosin and underwent left adrenalectomy. Pathology revealed an adrenal corticoadenoma with no evidence of pheochromocytoma. Over the next 2 years, urine norepinephrine and normetanephrine remained significantly elevated with no MIBG avid disease. Years later, he was diagnosed with severe OSA and treated with continuous positive airway pressure. Urine testing done once OSA was well controlled revealed complete normalization of urine norepinephrine and normetanephrine with substantial symptom improvement. It was concluded that the patient never had a pheochromocytoma but rather an adrenal adenoma with biochemistry and symptoms suggestive of pheochromocytoma due to untreated severe OSA. Pseudo-pheochromocytoma is a rare presentation of OSA and should be considered on the differential of elevated urine catecholamines and metanephrines in the right clinical setting.

LEARNING POINTS

Obstructive sleep apnea (OSA) is a common condition among adults. OSA may rarely present as pseudo-pheochromocytoma with symptoms of pallor, palpitations, perspiration, headache, or anxiety. OSA should be considered on the differential of elevated urine catecholamines and metanephrines, especially in patients with negative metaiodobenzylguanidine (MIBG) scan results.

First European Haplotype of Echinococcus multilocularis Identified in the United States: An Emerging Disease?

BACKGROUND

Echinococcus multilocularis is one of the most severe and lethal parasitic diseases of humans, most often reported in Europe and Asia. Only 1 previous case has been documented in the contiguous United States from Minnesota in 1977. European haplotypes have been identified in carnivores and domestic dogs as well as recently in patients in western and central Canada.

METHODS

We used immunohistochemical testing with the monoclonal antibody Em2G11 and a species-specific enzyme-linked immunosorbent assay affinity-purified antigen Em2, as well as COX1 gene sequencing.

RESULTS

Using pathology, immunohistochemical staining, specific immunodiagnostic testing, and COX1 gene sequencing, we were able to definitively identify E. multilocularis as the causative agent of our patient's liver and lung lesions, which clustered most closely with the European haplotype.

CONCLUSIONS

We have identified the first case of a European haplotype E. multilocularis in the United States and the first case of this parasitic infection east of the Mississippi River. Given the identification of this haplotype in Canada, this appears to be an emerging infectious disease in North America.

Hepatocellular Carcinoma Misdiagnosed as a Liver Abscess - A Story of Misdiagnosis and Long-Term Malignant Disease Control

Hepatocellular carcinoma (HCC) is the most common liver malignancy. The presentation of HCC is highly variable which can delay diagnosis. However, the early diagnosis of HCC can significantly improve prognosis. A rare presentation of a patient with a new diagnosis of HCC with sepsis is described. A 56-year-old male presented septic with abdominal pain and a background of a chronic foot infection. The septic screen identified echocardiographic evidence of vegetations on the aortic and mitral leaflets. Also, an ultrasound of the abdomen identified multiple hypoechoic lesions suspicious for liver abscesses. Multiple attempts of ultrasound-guided aspiration of liver lesions were unsuccessful and he had a tumultuous course with recurring fevers over a period of six months. The diagnosis of HCC was eventually confirmed after the lesion eroded into his anterior gastric wall which caused an upper gastrointestinal bleed. He responded well to transarterial chemoembolization (TACE) and palliative radiation therapy. At four-year follow-up and after 11 TACE procedures, he is well without liver dysfunction and independent with daily activities.