Treatment of thyroid differenciated carcinoma is controversial. In cas
e of papillary microcarcinoma a low malignancy is usually considered a
nd a limited surgical excision is currently used. We describe 49 cases
with papillary tumor < 1 cm. Their high frequency (51% of all differe
nciated carcinoma discovered in the same period), current mode of thei
r diagnosis (incidental histological findings: N = 48), and constant t
umoral situation in extra nodular parenchyma are emphasised. In spite
of median tumor size < 2 mm, 8 % had extra thyroidal tumoral extent at
diagnosis (node metastasis: N = 3; bone: N = 1). In one case with mul
tifocal lesions in both lobes, an unilateral thyroidectomy would have
missed controlateral periglandular metastatic nodes. Diagnosis of the
case with asymptomatic bone metastatis was clearly attributable to rad
ioiodine therapeutic use. These results suggest an heterogeneous progn
osis of papillary microcarcinoma, with some cases requiring total bila
teral thyroidectomy and radioiodine remnants ablation (e.g. Tumors inv
ading peripheral thyroid tissue that seem at higher risk of extra glan
dular extension).