Papillary microcarcinoma of the thyroid gland

Abstract

Papillary microcarcinomas are a specific subgroup of papillary thyroid cancer. They have the same histological features as papillary thyroid cancer but are 1.0 cm or less in diameter. These tumours are a common incidental finding at autopsy and in thyroid glands excised for other pathology. This tumour can metastasize to regional lymph nodes but its ability to cause significant morbidity and mortality has been questioned. As papillary microcarcinomas can represent up to 30 per cent of all papillary cancers seen in a thyroid surgeon's practice, they are an important group. The aim of this review article is to outline the natural history of papillary microcarcinoma and to offer therapeutic management strategies.

Papillary microcarcinoma of the thyroid—Prognostic significance of lymph node metastasis and multifocality

“…15 Based on the high incidence in autopsy studies in Finland, this common incidental finding was viewed as a normal finding, and tumors that measured Յ 5 mm were considered tumor instead of carcinoma to avoid unnecessary surgeries. 15 Most of the autopsy series did not reveal differences in incidence with respect to gender, 15,19 age, 15,20 thyroid size, 14 or multifocality. 14 Further subdivision of tumors by size (Յ 5 mm vs. Ͼ 5 mm) was suggested by Kasai and Sakamoto because of the lower frequency of LN metastasis and extrathyroid extension in the subgroup of patients with smaller tumors.…”

“…15 Most of the autopsy series did not reveal differences in incidence with respect to gender, 15,19 age, 15,20 thyroid size, 14 or multifocality. 14 Further subdivision of tumors by size (Յ 5 mm vs. Ͼ 5 mm) was suggested by Kasai and Sakamoto because of the lower frequency of LN metastasis and extrathyroid extension in the subgroup of patients with smaller tumors. 19 Studies in our hospital 21 and in Japan 22 revealed a temporal trend toward decreasing tumor size of PTC.…”

“…16 Lymph node (LN) metastases were detected in 3.1-18.2% of patients. 14,15 Marked geographic differences in incidence rates were noted: 1% in Brazil, 12 13% in Hong Kong (unpublished data from Queen Elizabeth Hospital), 11.3-28.4% in Japan, 4,13,17 1.5% in Greece, 18 and 35.6% in Finland. 15 Based on the high incidence in autopsy studies in Finland, this common incidental finding was viewed as a normal finding, and tumors that measured Յ 5 mm were considered tumor instead of carcinoma to avoid unnecessary surgeries.…”

“…8,11 One study reported a long-term recurrence rate of 6% at 20 years. 6 In autopsy studies, the incidence of small PTC varied from 1.0% to 35.6%, [12][13][14][15] depending on the thoroughness of examination (e.g., the number of sectioning levels) and diagnostic criteria. 16 Lymph node (LN) metastases were detected in 3.1-18.2% of patients.…”

Microcarcinoma da tireóide: experiência e conduta em clínica privada

“…O microcarcinoma, definido pela WHO como menor que 1 cm (9), pode ser diagnosticado como: incidentaloma encontrado após tratamento de outras tireoidopatias (10); lesão oculta encontrada na investigação de metástase cervical; no rastreamento da forma familiar descrito por Lupoli (11); ou como diagnósti-co inicial em apenas 4 a 12,6% (12). Na maioria das vezes, seu tipo histológico é o papilífero e representa 30% de todos os carcinomas da tireóide (13).…”