Fine‐needle aspiration diagnosis of primary hydatid disease of the thyroid; first reported case in the USA

Abstract

Echinococcosis or hydatid disease (HD) is a parasitic disease caused by species of the Echinococcus genus. Since the incidence of HD in the USA is very low and the primary HD of the thyroid is extremely rare even in endemic regions, the occurrence of primary thyroid HD is exceptional in the USA. Thyroid HD is rarely diagnosed by fine-needle aspiration (FNA). Our literature review revealed less than ten cases of primary HD of thyroid diagnosed by FNA worldwide. Hereby, we report the first case of a primary thyroid HD diagnosed by fine-needle aspiration in the USA.

Primary Hydatid Cyst of the Thyroid Gland Revealed by Primary Hypothyroidism

“…Turkish series of 661 operated HC including 134 of unusual localization (0.15%) and a single case was also noted in Çakir M, et al [8] series of 157 HC of unusual localization (0.6%). The few other observations found in the literature were reported as sporadic cases [13][14][15][16][17][18][19][20][21].…”

“…It most frequently shows a cystic mass with a thin wall, sometimes with detached membrane (water-lily-sign) or the presence of daughter cysts (rosette-like or honeycomb cyst). These aspects (water-lily-sign, rosette-like or honeycomb cyst) are suggestive of the hydatic origin [13][14][15][16][17][18][19][20][21]. However, the sensitivity of ultrasound remains low.…”

“…Punctures of hydatid cysts have long been proscribed because of the theoretical risk of swarming and anaphylactic shock [21], but cytology by aspiration of cyst contents, looking for scolex is very specific when it is positive. The search for other localizations in a patient with thyroid HC is systematic (thoracic radiography, abdominal ultrasonography, and abdominopelvic CT) to distinguish primary forms from secondary ones and to guide the therapeutic management [15][16][17][18][19][20][21].…”

“…Treatment of thyroid HC is essentially surgical, consisting of excision of cysts to prevent complications such as: choking, vocal cord paralysis, intra tracheal rupture, suppuration or intra cystic haemorrhage [13][14][15][16][17][18][19][20][21][22]. Three main options are possible: simple resection and partial or total pericystectomy.…”

Cytomorphologic features of echinococcal cysts

“…Although it is a rare disease in the United States (<1 case per million), echinococcosis (hydatid disease) is a zoonotic infection endemic to several regions throughout the world, particularly in areas where sheep or cattle‐raising is prevalent, including Australia, New Zealand, Middle East, South America, parts of North America, and countries bordering the Mediterranean . Both patients presented in this report were exposed to the parasites either by traveling to or emigrating from the above areas.…”