BACKGROUND: Micropapillary Thyroid Cancer (MPTC) is defined as papillary thyroid cancer measuring less than one centimeter in size. Although there have been many studies involving MPTC, there is still a gap in the understanding of the behavior of MPTC in the Filipino population.

OBJECTIVES: This study aims to determine risk factors and prevalence of locoregional and distant metastasis upon diagnosis and the risk factors for persistent disease after thyroidectomy among patients with MPTC.

METHODS: This is a retrospective study that included all patients with histopathology result of MPTC from January 1, 2004 to December 31, 2012. Patients who had accompanying well differentiated thyroid tumors other than MPTC and those patients with a diagnosis of MPTC with no follow up after the surgery were excluded.

RESULTS: A total of 109 patients were eligible for the study. The mean age was 46.06 years with majority being female (96.3%). The average tumor size was 0.502 cm. Seventy-five  (68.81%) received Radioactive Iodine Therapy (RAI) after thyroidectomy. Nineteen patients (17.92%) had multifocal disease while 11 (10.09%) had multicentric disease. Fifteen patients (13.76%) had locoregional metastasis while eight (7.34%) had distant metastasis on diagnosis. Out of the 91 patients included for analysis of persistent disease, eight patients (8.79%) had persistent disease. Exact logistic regression showed that locoregional metastasis (p=0.0044) is a risk factor for distant metastasis at diagnosis. Age, sex, tumor size, multifocality, multicentricity, RAI, and extent of surgery did not reach statistical significance as independent risk factor for locoregional, distant metastasis on diagnosis, and persistent disease.

CONCLUSION: Although MPTC is considered an indolent type of well differentiated thyroid cancer, there are certain patients who may present with metastasis at diagnosis. Our data showed that locoregional metastasis is a risk factor for distant metastasis on diagnosis in patients having MPTC. 

Human ; Male ; Female ; Aged ; Middle Aged ; Adult ; Thyroidectomy ; Iodine ; Prevalence ; Thyroid Cancer, Papillary ; Thyroid Neoplasms ; Adenocarcinoma

Objective: This study describes the clinical data of adult patients who underwent Fine Needle Aspiration Biopsy (FNAB) of thyroid nodule(s) with a cytologic diagnosis of Atypia or Follicular Lesion of Undetermined Significance (AUS or FLUS) at St. Luke’s Medical Center from January 2012 to October 2013. Methodology: Adult patients who underwent FNAB of the thyroid nodule with a cytologic diagnosis of AUS or FLUS were studied retrospectively using the ultrasound result, initial consultation form and operative techniques of these patients. The cytologic and histopathologic diagnoses were retrieved through the electronic Healthcare-Results Management System. Results and Conclusion A third (34%) of the patients with a cytologic diagnosis of AUS or FLUS (8.9%) underwent surgery. Of the 68 patients who underwent surgery, 44 were benign and 24 were malignant with a malignancy rate of 35.3%. Preoperatively, there were no ultrasound characteristics or microscopic descriptions significantly associated with malignancy. The recommendation of the Bethesda System to do a repeat FNAB in these thyroid nodules should, therefore, be reconsidered.
Biopsy, Fine-Needle ; Thyroid Nodule ; Cytology