A woman who complained of having a sore throat was found to have a live worm lodged in her tonsils.
The anonymous 25-year-old woman from Tokyo visited St Luke’s International hospital in the Japanese capital after experiencing throat pain and irritation for five days.
After a blood test, and upon a quick inspection, doctors discovered "a black moving worm" in her left tonsil.
The rare case, which was published in the American Journal of Tropical Medicine and Hygiene, said: "The worm body was black, 38mm long, 1mm wide, and was moulting the outer cuticle" - with the cause being identified as the sushi the woman ate.
The entry also included a picture of the disgusting worm, which was still alive after doctors extracted it with tweezers.
After the procedure the patient's symptoms improved rapidly.
The entry read: "DNA and the fact that the worm was in exuviation revealed this worm was a fourth-stage larva of Pseudoterranova azarasi."
This is a parasite that can infect people who consume raw or uncooked fish, including sushi and sashimi.
The journal noted that the woman had in fact eaten a meal of "assorted sashimi" - a raw fish dish - five days prior, and had suffered a sore throat ever since - that's how they knew the sushi was to blame.
It continued: "Although oropharyngeal infection is rare, it is known to cause 'tingling throat syndrome' and cough (a sudden, forceful hacking sound)."
But although this was classed a rare case, the woman is not the only unfortunate diner.
The study said that the number of reported cases had "markedly increased worldwide" due to the growing popularity of sushi and sashimi.
But, don't worry, you can continue eating your sushi with confidence as the journal said this parasite in particular is pretty uncommon.
