Noninvasive follicular thyroid neoplasm with papillary-like nuclear features

A type of thyroid neoplasm

Noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) is a type of thyroid neoplasm that exhibits certain histological characteristics similar to papillary thyroid carcinoma (PTC) but is considered to have a very low risk of malignancy. This entity was introduced to reduce overtreatment of indolent thyroid tumors.

Histopathology

NIFTP is characterized by a follicular growth pattern and nuclear features similar to those seen in papillary thyroid carcinoma. The tumor is encapsulated or well-circumscribed, and there is no evidence of invasion into the surrounding thyroid tissue or blood vessels.

Histopathology of NIFTP

The nuclear features include:

• Nuclear enlargement
• Overlapping and crowding
• Irregular nuclear contours
• Optical clearing of the nuclei

Nuclear features of NIFTP showing overlapping and crowding

Diagnosis

The diagnosis of NIFTP is primarily based on histological examination of the thyroid tissue. It requires careful evaluation to distinguish it from other forms of thyroid carcinoma, particularly the encapsulated follicular variant of papillary thyroid carcinoma.

Thyroid NIFTP tumor capsule

The criteria for diagnosing NIFTP include:

• Encapsulation or clear demarcation from surrounding tissue
• Follicular growth pattern
• Absence of true papillae
• No psammoma bodies
• No vascular or capsular invasion

Management

The management of NIFTP is less aggressive than that of other thyroid carcinomas due to its low risk of recurrence and excellent prognosis. Surgical removal of the affected lobe of the thyroid (lobectomy) is often sufficient, and total thyroidectomy is generally not required.

Prognosis

NIFTP has an excellent prognosis with a very low risk of recurrence or metastasis. The reclassification of this entity from a carcinoma to a neoplasm reflects its indolent nature and aims to prevent overtreatment.

Related pages

• Thyroid cancer
• Papillary thyroid carcinoma
• Follicular thyroid carcinoma