Nuclear grooves may be seen in other thyroid lesions including hashimoto s disease adenomatous hyperplasia and. Another characteristic of the papillary cancer nucleus is the nuclear groove. The 12 specimens of histologically proven cystic papillary carcinoma diagnosed by fnab as atypical exhibited similar nuclear features i e nuclear enlargement fine chromatin and nuclear grooves as observed in many of the benign thyroid cysts.
A fine needle aspiration biopsy specimen suspicious for papillary thyroid cancer original magnification 510 demonstrating marked cellularity a papillary formation b and nuclear inclusions and grooves arrows c from a patient with a final pathologic diagnosis of papillary carcinoma. A distinction is made between well differentiated thyroid carcinomas papillary or follicular carcinoma and poorly differentiated carcinomas medullary or anaplastic carcinoma. Thyroid cancers also disproportionately affect women.
The majority of thyroid cancers are well differentiated carcinomas the principal risk factors are exposure to ionizing radiation and genetic predisposition. However they become an important diagnostic feature when associated with an oval enlarged nucleus with fine chromatin. Nuclear grooves alone are nonspecific and can be seen in a variety of neoplastic and non neoplastic cells including macrophages and benign follicular cells.
Nuclear grooves were also observed in two of the 113 non ptc cases 1 8 both of which were colloid nodules one with extensive hurthle cell change. Among the ptc cases grooved nuclei were found in all 11 100 intranuclear inclusions in nine 82 papillary fragments in seven 64 and psammoma bodies in two 18. The well differentiated thyroid cancer such as follicular and papillary carcinomas account for 95 of all thyroid cancer cases and are generally associated with a good prognosis and or survival rate when diagnosed early 3 4 on the other hand the poorly or undifferentiated anaplastic thyroid carcinoma albeit a rare cancer is almost always fatal 5.
Eighty eight percent of papillary carcinoma had nuclear grooves in or 20 tumor cells whereas none of the other thyroid diseases exceeded this level. In h e stained smears of papillary carcinoma the number of cells with nuclear grooves 227 3 99 96 sd was significantly higher as compared to other thyroid disorders p 01 to 001. Ovarian tumors including brenner tumors adult granulosa cell tumors and transitional cell tumors.
It is a characteristic feature of papillary thyroid carcinoma but has also been seen in other types of thyroid neoplasms as well as in non neoplastic thyroid lesions. It can be present in. A nuclear groove is an invagination of the nuclear envelope in the longitudinal axis.
