Case Report: Multifocal non-invasive follicular thyroid neoplasm with papillary-like nuclear features presenting in a female child

First bilateral non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) co-occurring with bilateral papillary thyroid microcarcinoma. Case report and literature review

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Non-invasive follicular thyroid neoplasm with papillary-like features (NIFTP) is a benign lesion with no evidence of recurrence or metastasis.

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NIFTP is managed with partial or total thyroidectomy which is sufficient to achieve total cure.

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Co- coexistence of NIFTP and papillary microcarcinoma can be managed by resection and radioactive iodine ablation of the thyroid.

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The current case in probably the first reported bilateral NIFTP with bilateral papillary microcarcinoma.

Introduction

Non-invasive follicular thyroid neoplasm with papillary-like features (NIFTP) is a recently characterized lesion with very low malignant potential. This has allowed for less aggressive management of this tumor subtype. Papillary thyroid carcinoma (PTC) has malignant potential and requires different considerations in management.

Presentation of case

A 33-year-old woman presented to our Thyroid Surgery Clinic with a left neck swelling slowly enlarging over 4 years, and recent right-sided neck pain. Neck ultrasound and fine needle aspiration for cytology found bilateral thyroid nodules, labelled as ‘follicular lesion of undetermined significance’ (FLUS). Final pathology report after total thyroidectomy identified four distinct tumors: bilateral NIFTP lesions and bilateral papillary microcarcinomas.

Discussion

Management of NIFTP comprises partial or total thyroidectomy without further intervention. Management of PTC is the same but with the possible addition of radioactive ablation due to the increased malignant potential. This is the first report of bilateral NIFTP lesions and bilateral papillary microcarcinomas co-occurring together in the same patient, so management was challenging. The decision was made to give the patient low dose radioactive iodine ablation and continue monitoring. Ultrasound of the neck follow up 6 months later showed no residual thyroid tissue or local recurrence.

Conclusion

Although rare, NIFTP can co-occur with PTC. Bilateral NIFTP with bilateral PTC is extremely rare. Surgeons and pathologists need to be aware of this rare entity that can co-occur in both thyroid lobes. Total thyroidectomy is the definitive treatment. Post-surgery surveillance is important and follow up needs to be watchful for any recurrence or metastasis.