Descriptive analysis of papillary thyroid microcarcinomas in a single-center

Elena Fernandez Gonzalez; Isabel Huguet Moreno; Jose Luis Munoz; Nerea Aguirre Moreno; Begona Pla Peris; Clara Marijuan Sanchez; Marta Araujo Castro; Ana Ramos-Levi; Monica Marazuela Azpiroz; Manuel Luque Ramirez; Marcos Lahera Vargas

doi:10.1530/endoabs.56.P1166

Introduction: The incidence of papillary thyroid microcarcinomas (MPT, max diameter≤10 mm) has increased in recent years. Most have a very good prognosis but some have growth during follow-up, lymph node and / or distant metastases.

Material and methods: We performed a single-center, retrospective cohort study, n=114 patients (86% women, average age 48.3 years), diagnosed with MPT between 1998 and 2012. Risk stratification system (ATA 2015): 10 high, 34 intermediate and 70 low risk at the diagnosis. Therefore, 38,6% had extrathyroid disease. The prevalence of certain clinical and histological characteristics that could predict a worse evolution was studied. We also analyzed excellence response (RE), indeterminate (RIN), biochemical incomplete (BIN) and structural incomplete (EIN) in the different ATA groups after 2 and 5 years. In low risk group, we differentiated those who had not received iodine. Statistical analysis SPSSv.15.0.

Results: Univariate and descriptive analysis according to ATA groups 1, 2 and 3: age (53.2±14.4, 41.7±12.2, 33±18 years; P=0.004), male sex (4.3, 26.5, 40%; P<0.001), incidental diagnosis (51.4, 17.6, 0%; P<0.001), isthmus location (7.1, 14.7, 0%; P=0.01), capsular invasion (4.3, 44, 40%; P<0.001), vascular invasion (0,2, 4.5%; P=0.07), tumor size (5.9±0.4, 6.1±0.3, 6.5±0.3 mm; P=0.015), previous TSH (1.8±1.4, 2.0±0.6, 2.1±1.2; P=0.09). Isthmus location was associated with N1 (P=0.005). Initial treatment: hemithyroidectomy (8.5,0,0%), central lymphadenectomy (8.6, 26.5, 40%), lateral (1.4, 50, 80%), radioioidine (32.8, 100, 100%). Retreatment after 2 years in ATA 2/3 group: 2 relymphadenectomy, 13 new radioioidine dose, 1 ethanol injection. Retreatment between 2 and 5 years in ATA 2/3: 3 surgical reintervention, 5 another radioioidine dose. Thus, 18,4% required at least one more treatment in the follow-up.


2 years response					5 years response
	RE	IND	BIN	EIN	RE	IND	BIN	EIN
ATA1 (Iodine yes/no)	82.61/66.7%	17.4%/33.3%	0%/2.3%	0%/0%	86.36%/72.3%	13.64%/22.26%	0%/0.04%	0%/0%
ATA2	64.52%	12.90%	12.90%	9.67%	70.83%	8.33%	12.5%	4.16%
ATA3	33%	22%	11%	33%	28.6%	42.86%	14.29%

Conclusions: In our cohort: younger age, male sex, capsular and vascular invasion, larger tumor size and higher TSH, were more prevalent in MPTs with higher initial risk of recurrence. Only three patients presented distant metastases, and all from the diagnosis. Tumors that did not present lymph node metastases at diagnosis did not show it in the evolution either. Extrathyroidal involvement in our series was very frequent. Nevertheless, this did not translate into an increased mortality but in the need for more treatments during the follow-up.

Endocrine Abstracts

P1166