Hürthle cell

(Bethesda category IV, rather than Hürthle cell hyperplasia), Pap stain. While Hurthle cells can occur in healthy thyroid glands, and Graves' disease. arising from the follicular epithelium of the thyroid gland. and was formerly considered a subtype of follicular thyroid cancer. The mitochondrial DNA of Hürthle cell carcinoma contain somatic mutations. Hürthle cell carcinomas consists of at least 75% Hürthle cells. ==Diagnosis==

Hürthle cell adenomas are most likely diagnosed much more frequently than Hürthle cell carcinomas. Typically a painless thyroid mass is found in patients with this type of cancer. Hürthle cell carcinomas are characterized as either minimally invasive or widely invasive tumors. While the minimally invasive or encapsulated carcinoma is fully surrounded by a fibrous capsule, the widely invasive carcinoma shows extensive area of both capsular and vascular invasion with the leftover capsule typically difficult to identify. Classification is important since widely invasive tumors can have outcomes with a 55% mortality rate. The female to male ratio for Hurthle cell adenomas is 8:1, while the ratio is 2:1 for the malignant version. Hürthle cell cancer tends to occur in older patients. The median age at diagnosis for Hürthle cell carcinomas is approximately 61 years old. ==Histology==

Hürthle cells arise from the follicular epithelium. A Hürthle cell is larger than a follicular cell, and polygonal with distinct cell borders. Some of these cells can contain up to 5,000 mitochondria, which fills the cytoplasm to the point of nearly excluding other organelles. ==Treatment==

A non-minimally invasive Hürthle cell carcinoma is typically treated by a total thyroidectomy followed by radioactive iodine therapy. A Hürthle cell adenoma or a minimally invasive tumor can be treated by a thyroid lobectomy, although some surgeons will perform a total thyroidectomy to prevent the tumor from reappearing and metastasizing. A modified radical neck dissection may be performed for clinically positive lymph nodes. ==History==

The Hürthle cell is named after German histologist Karl Hürthle, who investigated thyroid secretory function, particularly in dogs. However, this is a misnomer since Hürthle actually described parafollicular C cells. ==See also==