A synchronous papillary and follicular thyroid carcinoma presenting as a large toxic nodule in a female adolescent

A patient with a rare co-occurrence of papillary and follicular thyroid carcinomas

The occurrence of papillary and follicular thyroid carcinoma as a collision tumor is rare. We report on a case of a collision tumor consisting of papillary and follicular thyroid carcinoma treated successfully with surgery and radioiodine ablation.

Synchronous Papillary and Follicular Carcinoma with Scalp and Nodal Metastasis: A case report with review of literature

Collision tumor comprise of existence of two histologically distinct and separate neoplasms in any organ. Thyroid gland is an uncommon site for these tumors, with frequently involved organs being liver, adrenal and stomach. Even among the synchronous tumors of thyroid, papillary and medullary carcinoma are most commonly reported. The present case reports a rare presentation of a collision tumor comprising of papillary and follicular carcinoma with scalp metastasis from the follicular carcinoma and lymph nodal metastasis from the papillary component. It is essential for the clinician to be aware of such an entity so as to guide further treatment and management.

Collision tumor of a papillary and follicular thyroid carcinoma: a case report

BACKGROUND

Papillary thyroid carcinoma (PTC) and follicular thyroid carcinoma (FTC) are common differentiated thyroid cancers, but the detection of a collision tumor is an extremely rare event.

CASE PRESENTATION

The patient was a 69-year-old Japanese female with multiple cervical lymph node swellings and a thyroid tumor. Preoperative fine needle aspiration cytology of the enlarged lymph node revealed a cytological diagnosis of papillary thyroid carcinoma (PTC). A total thyroidectomy, right cervical dissection and paratracheal dissection were performed. Histopathological and immunohistochemical analyses of resected specimens revealed a collision tumor of PTC and FTC. Multiple metastases of papillary carcinoma were found in the dissected lymph nodes. In the PTC lesion, IHC for BRAF (V600E) was positive but negative for the FTC lesion. Genetic analyses further revealed a TERT promoter C228T mutation in PTC and a NRAS codon 61 mutation in FTC. The patient died of recurrent cancer 8 months after surgery.

CONCLUSIONS

A case of a collision tumor of PTC and FTC is very rare, and even fewer cases have been subjected to genetic scrutiny. The present case was successfully diagnosed by pathological examination using immunohistochemical and genetic analyses. The TERT promoter mutation in the PTC lesion was consistent with the aggressive behavior of the cancer.

Clinical value of SMI Combined with Low-Dose CT Scanning in differential diagnosis of Thyroid Lesions and Tumor Staging

Objectives

To investigate the clinical value of Superb Microvascular Imaging (SMI) combined with low dose CT scanning in differential diagnosis of thyroid lesions and tumor staging.

Methods

A total of 120 patients with thyroid nodules admitted to the Chinese PLA General Hospital from January 2017 to July 2020 were selected. Paired design was adopted in this study. SMI and SMI combined with low-dose CT scanning were respectively carried out to these patients. The results were judged by two senior imaging physicians and two senior sonographers respectively. And t-test, χ² test, Pearson correlation coefficient check and other methods were adopted to comparatively analyze the above two methods and the pathological results after operation or puncture.

Results

Compared with pathologic findings, the coincidence rate of SMI was 40%, and the coincidence rate of SMI combined with low dose CT scanning was 84%. The difference was significant (p=0.00); among the 120 thyroid nodule patients, 50 were diagnosed as malignant by pathological diagnosis, and 70 as benign; 27 malignant cases and 93 benign cases were detected by SMI; 48 malignant cases and 72 benign cases were detected by SMI combined with low dose CT scanning. The sensitivity and accuracy of the latter were significantly higher than those of the former, and the difference was statistically significant (p=0.00); the enhancement, edge sharpness and homogeneity of SMI increased with the increase of tumor malignancy, showing positive correlation property.

Conclusion

SMI combined with low dose CT scanning has a higher diagnostic coincidence rate. Its sensitivity and accuracy are significantly superior. With the increase of tumor malignancy, the enhancement and unhomogeneity of SMI increase, and the edge is more blurred. That suggests: with the increase of tumor malignancy, neovascularization in the tumor is more obvious and more unevenly distributed; the increase of edge blur indicates more obvious tumor infiltration. The method has considerable clinical value for predicting the malignancy of tumors.