Thyroid abscess associated with thyrotoxicosis caused by Yersinia enterocolitica subsp. palearctica in a patient with follicular adenoma of the thyroid gland.

BACKGROUND: Yersinia enterocolitica is a gram-negative zoonotic bacterial pathogen that is typically transmitted via the fecal-oral route. The most common clinical manifestation of a Y. enterocolitica infection is self-limited gastroenteritis. Although various extraintestinal manifestations of Y. enterocolitica infection have been reported, there are no reports of thyroid abscesses.

CASE PRESENTATION: An 89-year-old Japanese man with follicular adenoma of the left thyroid gland was admitted to our hospital with a 2-day history of fever and left neck pain. Laboratory tests revealed low levels of thyroid stimulating hormone and elevated levels of free thyroxine 4. Contrast-enhanced computed tomography showed low-attenuation areas with peripheral enhancement in the left thyroid gland. He was diagnosed with thyroid abscess and thyrotoxicosis, and treatment with intravenous piperacillin-tazobactam was initiated after collecting blood, drainage fluid, and stool samples. The isolated Gram-negative rod bacteria from blood and drainage fluid cultures was confirmed to be Y. enterocolitica. He was diagnosed with thyroid abscess and thyrotoxicosis due to be Y. enterocolitica subsp. palearctica. The piperacillin-tazobactam was replaced with levofloxacin.

CONCLUSION: We report a novel case of a thyroid abscess associated with thyrotoxicosis caused by Y. enterocolitica subsp. palearctica in a patient with a follicular thyroid adenoma.