Black thyroid gland and tracheal cartilage.

A woman in her 70s with a history of chronic minocycline use presented with complaints of a non-tender posterior neck mass. A thyroid gland ultrasound showed a highly suspicious right thyroid nodule. A total thyroidectomy revealed darkened discolouration of the thyroid gland and tracheal cartilage. The pathology report showed dark brown granules representing melanin. Chronic minocycline usage is known to cause pigmentation of nails, teeth, bones and the thyroid gland. Our case highlights the importance of recognising that long-term use of minocycline can cause discolouration of the thyroid and tracheal cartilage. Current case studies do not show any adverse health effects associated with black thyroid and tracheal cartilage. For patients who are to undergo neck surgery, physicians need to be aware of this side effect, and that further intervention, such as surgical resection, may not be required.

Lung disease associated with occupational styrene exposure.

Despite reports of pulmonary toxicity due to styrene, guidelines on acceptable styrene exposure levels have been based on risk of cancer and central nervous system and liver toxicity and not on respiratory effects. Many reports have linked exposure to styrene vapor in occupational settings to various forms of non-malignant pulmonary disorders including bronchiolitis, hypersensitivity pneumonitis, and occupational asthma. We report two cases in which the same tasks performed in a single workplace resulted in exposure to styrene vapor with subsequent development of acute respiratory symptoms associated with impaired gas exchange and imaging and histopathologic findings consistent with bronchiolitis and organizing pneumonia. Both patients gradually recovered once their workplace exposure to styrene was terminated. Clinicians, employers, and insurers should be aware of the potential for pulmonary toxicity from exposure to styrene.