# Non-invasive Follicular Thyroid Neoplasm With Papillary-Like Nuclear Features (NIFTP) Arising in Struma Ovarii: A Pathologist’s Perspective

## TL;DR

This paper reports a rare case of a non-malignant thyroid tumor found in ovarian tissue, highlighting the challenges in diagnosing and managing such a rare condition.

## Contribution

The novelty lies in presenting the second documented case of NIFTP arising in struma ovarii, offering insights into its histological and clinical management challenges.

## Key findings

- NIFTP can occur in struma ovarii, a rare ovarian tumor composed of thyroid tissue.
- This case highlights the need for careful histological evaluation to distinguish NIFTP from malignancy.
- The rarity of this condition makes its clinical management and follow-up challenging.

## Abstract

Struma ovarii is a rare monodermal ovarian teratoma predominantly composed of thyroid tissue. It is usually benign, although malignant transformation is occasionally observed. Non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) is a recently defined non-malignant entity with indolent behavior, and its emergence in struma ovarii is very uncommon. It requires careful histological analysis, and because of the unusual occurrence of this tumor, its management and follow-up remain challenging and debated. We report a case of NIFTP arising in struma ovarii in a 48-year-old patient. To the best of our knowledge, this is the second case report of this nature.