The factor of factor XI deficiency in thyroid neoplasia.

Forty-three patients with factor XI deficiency detected by prolonged partial thromboplastin times were reviewed over an 11-year period. They were predominantly Ashkenazim--18 men and 25 women--ranging in age from 20 to 92 years. Thirteen patients had a history of bleeding, and eight had a family history of factor XI deficiency. Six patients with thyroid disease with four significant tumors were found for a 9% incidence of associated neoplasia. These consisted of two adenomas and two papillary-mixed cancers in two men distinguished by an aggressive course by virtue of extensive nodal disease, local recurrence, and systemic metastases in whom factor XI was profoundly decreased. It would appear that there is an undue association of factor XI deficiency and thyroid neoplasia suggestive of a shared genetic disturbance. These cases illustrate the benefit of routine preoperative coagulopathy screening by use of prothrombin time, partial thromboplastin time, and platelet counts. Factor XI deficiency is an infrequent cause of excessive bleeding, and the operative morbidity of surgical management of affected individuals can be avoided by the use of fresh-frozen plasma before and after surgery.