Less Tumor Distance to Thyroid Pseudo Capsule Is Associated with Local Recurrence and Distant Metastases of Microscopic Papillary Carcinoma
Armando Gamboa-Dominguez, Blanca Camacho-Dominguez, Monica Chapa-Ibarguengoitia, Vanesa Rosas-Camargo, Ofelia Gonzalez-Trevino. Instituto Nacional de Ciencias Medicas y Nutricion SZ, Mexico City, DF, Mexico
Background: Studies of microscopic carcinoma (mPC) of the thyroid frequently does not separate persistence vs recurrent disease. A search for prognostic factors and the influence of tumor distance to thyroid pseudocapsule in mPC was our aim.
Design: A retrospective review of all thyroid specimens since 1968 through mid 2008 was performed searching for mPC. The number of tumors, size, location and its distance to thyroid pseudocapsule was measured. Ultrasonographic studies were re-evaluated and a blind search of suspicious lesions was performed. Demographic, clinical, surgical, and 131I administration were obtained from charts. TSH, T3, T4 and the clinical features were correlated with sonographic or tomographic data. Persistent disease was diagnosed when uninterrupted high TSH levels were identified after surgery or when metastases were evident during the first six months of follow-up, afterwards were considered as recurrences.
Results: A total of 1,343 thyroid specimens were evaluated and 511 PTC were identified in 40 years. 59(4.39%) were identified with mPC. Male to female ratio was 1:14 affecting mainly young patients (median age 43 years), with multiple tumors(51%) and bilateral affection(30%). Median tumor size was 7mm and cervical metastases observed in 42%. None with distant metastasis. Total or subtotal thyroidectomies were achieved in 50 persons, 36% with lymph node dissection. All but four patients received 131I. Tumor contact with thyroid pseudocapsule was documented in 13 patients. Ultrasonographic location of suspicious nodule was possible in 12. After 10y follow-up(17-480 months), 55 patients had uneventful follow-up, three had local lymph node recurrences and one mediastinal and lung metastases. These four received 131I and had tumors in contact with pseudocapsule. Nine patients with tumors in contact with pseudocapsule were free of metastases.