Abstract
The clinical importance of microscopic multicentricity in papillary thyroid carcinoma remains to be clarified. To gain knowledge from its clinical features, we reviewed 126 cases of papillary thyroid carcinoma from 2005 through 2010, treated primarily by surgery. We analyzed subject profiles, tumor size, stages T and N, invasion to surrounding organs, and surgical procedure. Of the 126 subjects, 13 (10.3%) had microscopic multicentric lesions (microscopic group), most often in pT1-2N1b disease (46.2%, p=0.00006, χ2), while pN0 disease was extremely rare (0%, p=0.0097, χ2). Macroscopic and microscopic multicentricity correlated significantly (p=0.015, χ2). No significant difference was seen between subjects with and without microscopic lesions in gender or primary tumor histology and size. Nodal metastasis involving the lateral compartment (N1b) was significantly more common in microscopic group subjects (10/13: 27/113, p=0.00026, χ2), with a significantly higher rate of overt invasion by metastatic nodes to surrounding organs (4/13: 3/66, p=0.012, χ2). The microscopic group tended to undergo total thyroidectomy more often than the macroscopic group (9/13: 42/113, p=0.053, χ2). Total thyroidectomy is the surgical method of choice in the presence of microscopic multicentric lesions to minimize local recurrence. Surgeons should keep in mind that resection required may be greater in cases with deep extracapsular invasion by metastatic nodes.
