Cribriform-morular variant of papillary thyroid carcinoma displaying poorly differentiated features.
Cribriform-morular variant of papillary thyroid carcinoma (CMVPTC) usually occurs in the setting of familial adenomatous polyposis (FAP) although it can rarely arise sporadically. Poorly differentiated thyroid carcinoma (PDTC) is a follicular cell-derived neoplasm with more aggressive behavior than well-differentiated carcinomas such as CMVPTC. We report the case of a 35-year-old woman without FAP history who presented a left neck mass and complained of back pain. Imagiological examinations revealed a nodule in the left lobe of thyroid and multiple nodular lesions in the bone and lungs suggestive of metastases. The patient was submitted to total thyroidectomy and radioactive iodine. The tumor was composed of CMVPTC and PDTC components that shared the same somatic APC gene mutation (p.Cys520Tyr_fsX534). Besides this mutation, no CTNNB1, BRAF, N-RAS, and H-RAS gene mutations were detected in any of the 2 components. To the best of our knowledge, this is the first report of a sporadic CMVPTC with transformation into PDTC. Although the majority of CMVPTCs carry an indolent clinical outcome, the coexistence of poorly differentiated areas may justify the aggressiveness of the CMVPTC reported here.
University of Porto, Porto, Portugal.
Tadao
T
Nakazawa
Ricardo
R
Celestino
José Carlos
JC
Machado
José Manuel
JM
Cameselle-Teijeiro
João
J
Vinagre
Catarina
C
Eloy
Fátima
F
Benserai
Samia
S
Lameche
Paula
P
Soares
Manuel
M
Sobrinho-Simões
D018263:Adenocarcinoma, Follicular / Q000235:genetics / Q000473:pathology*; D000328:Adult; D014408:Biomarkers, Tumor / Q000032:analysis; D002277:Carcinoma / Q000235:genetics / Q000473:pathology*; D002291:Carcinoma, Papillary; D005260:Female; D017491:Genes, APC; D006801:Humans; D007150:Immunohistochemistry; D009154:Mutation; D009378:Neoplasms, Multiple Primary / Q000235:genetics / Q000473:pathology*; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000235:genetics / Q000473:pathology*
D014408:Biomarkers, Tumor
cribriform-morular variant of papillary thyroid carcinoma; immunohistochemistry; molecular genetic analyses; poorly differentiated thyroid carcinoma; somatic APC gene mutation