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

Abstract

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 immunohistochemistry (IHC) 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 prompter 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 IHC and genetic analyses. The TERT promoter mutation in the PTC lesion was consistent with the aggressive behavior of the cancer.

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

“…Indeed, a handful of cases of PTC/FTC TCTs have reported genetic alterations in BRAF and TERT promoter in PTC and, NRAS mutations in FTC. However, among these limited number of cases, there is an unclear association between aggressiveness of disease and molecular phenotype 6,13,15 . Unfortunately, neither immunohistochemistry nor molecular testing was done in our case.…”

“…Additionally, lymph node metastasis was reported in four patients, 5,6,13,15 and distant metastasis to the rib/femur/shoulder bone, and adrenal gland have also been reported in four patients. 5,6,9,11 TCTs seemed to be located mainly either in the right lobe (n = 8), 3,10,[13][14][15] or both lobes (n = 10), [5][6][7][8][9]11,12,17,18 as opposed to only in the left lobe (n = 3). 3,16 Lastly, only 6 of 20 patients had TCTs with 2+ foci.…”

“…The most reported TCT is PTC and MTC as highlighted in a recent case series by Ryan et al 2 Though the co-occurrence of PTC and other carcinomas in the thyroid have been reported, 19 the coexistence of PTC and FTC are extremely rare, with only 20 cases reported in the English literature. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] Among the cases of co-existent PTC and FTC, the median age is 56 years old (range: 12-79 years old), with a female preponderance (66%) as per our review of current published English literature. Additionally, lymph node metastasis was reported in four patients, 5,6,13,15 and distant metastasis to the rib/femur/shoulder bone, and adrenal gland have also been reported in four patients.…”

“…[3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] Among the cases of co-existent PTC and FTC, the median age is 56 years old (range: 12-79 years old), with a female preponderance (66%) as per our review of current published English literature. Additionally, lymph node metastasis was reported in four patients, 5,6,13,15 and distant metastasis to the rib/femur/shoulder bone, and adrenal gland have also been reported in four patients. 5,6,9,11 TCTs seemed to be located mainly either in the right lobe (n = 8), 3,10,[13][14][15] or both lobes (n = 10), [5][6][7][8][9]11,12,17,18 as opposed to only in the left lobe (n = 3).…”

“…2 However, there are only 20 cases to date that describe the concurrent presentation of both PTC and follicular thyroid carcinoma (FTC). [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]…”