Succinate Dehydrogenase Complex: An Updated Review.

Succinate dehydrogenase (SDH) is uniquely tasked with a dual role in the essential energy-producing processes of a cell. Although SDH subunits and assembly factors form part of the same enzyme complex, mutations in their respective genes lead to significantly different clinical phenotypes. Remarkable discoveries in the last 17 years have led to the delineation of the SDH complex deficiency syndrome and its multiple pathogenic branches. Here we provide an updated overview of SDH deficiency in order to raise awareness of its multiple connotations including nonneoplastic associations and pertinent features of the continually growing list of SDH-mutant tumors so as to better direct genetic counseling and predict prognosis.

Pet Groomer's Lung: A novel occupation related hypersensitivity pneumonitis related to pyrethrin exposure in a pet groomer.

A 61-year-old man was evaluated for a 2 month history of cough and dyspnea without relevant exposures other than pyrethrin containing insecticidal sprays he used while grooming dogs almost daily. High Resolution Computed Tomography (HRCT) of the chest demonstrated a Non-Specific Interstitial Pneumonia (NSIP) pattern. Pulmonary function testing revealed an isolated mildly reduced diffusion capacity. Bronchoalveolar lavage (BAL) results confirmed the presence of foamy histiocytes, lymphocytes, and polymorphonuclear cells consistent with ongoing exposure. Open lung biopsy showed poorly formed granulomas and bronchiolitis. He was advised to avoid exposure to pyrethrin. While he declined to stop grooming dogs, on follow-up, his symptoms had improved with use of a P100 mask and better ventilation to protect himself when using the pet sprays. We conclude that sustained exposure to pyrethrin containing sprays in the pet grooming industry may be a risk factor for a novel occupation related hypersensitivity pneumonitis. ("Pet Groomer's Lung"). Am. J. Ind. Med. 60:141-145, 2017. © 2016 Wiley Periodicals, Inc.