title: Thyroid-like low-grade nasopharyngeal papillary adenocarcinoma: case report and literature review.
abstract: Thyroid-like low-grade nasopharyngeal papillary adenocarcinoma (TL-LGNPPA) is an extremely rare neoplasm characterized by morphological analogy to papillary thyroid carcinoma and abnormal expression of thyroid transcription factor-1 (TTF-1). Here we report a novel case of TL-LGNPPA with literature review. The patient was a 43-year-old woman complaining of nasal obstruction. Laryngoscopic study and computed tomography identified a pedunculated mass located on the posterior edge of the left nasal septum. Histologically, the tumor consisted of papillary growth of cuboidal or columnar epithelium. Tubular architecture and a spindle cell component were also observed focally. Some tumor cells exhibited intra-nuclear cytoplasmic inclusions. Immunohistochemically, the neoplastic cells were positive for pancytokeratin (AE1/AE3), CK7, CK19, TTF-1, vimentin and HBME1, but negative for thyroglobulin, Pax8 and CK5/6. Ki67-labeling index reached 5% in the most concentrated spot. Despite the morphological and immunohistochemical similarity to papillary thyroid carcinoma, no BRAF V600E mutation was detected by mutation-specific immunohistochemistry. The patient had neither local recurrence nor distant metastasis 19 months after removal of the tumor.
authors.affiliation: Department of Pathology, School of Medicine, University of Yamanashi, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Oishi
authors.affiliation: Department of Pathology, School of Medicine, University of Yamanashi, Japan. Electronic address: ktetsuo@yamanashi.ac.jp.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Kondo
authors.affiliation: Department of Pathology, School of Medicine, University of Yamanashi, Japan.
authors.forename: Tadao
authors.initials: T
authors.lastname: Nakazawa
authors.affiliation: Department of Pathology, School of Medicine, University of Yamanashi, Japan.
authors.forename: Kunio
authors.initials: K
authors.lastname: Mochizuki
authors.affiliation: Department of Pathology, School of Medicine, University of Yamanashi, Japan.
authors.forename: Kazunari
authors.initials: K
authors.lastname: Kasai
authors.affiliation: Department of Pathology, School of Medicine, University of Yamanashi, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Inoue
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, School of Medicine, University of Yamanashi, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Yamamoto
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, School of Medicine, University of Yamanashi, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Watanabe
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, School of Medicine, University of Yamanashi, Japan.
authors.forename: Kyousuke
authors.initials: K
authors.lastname: Hatsushika
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, School of Medicine, University of Yamanashi, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Masuyama
authors.affiliation: Department of Pathology, School of Medicine, University of Yamanashi, Japan.
authors.forename: Ryohei
authors.initials: R
authors.lastname: Katoh
mesh_terms: D000231:Adenocarcinoma, Papillary / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology*; D000328:Adult; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002277:Carcinoma / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology*; D002291:Carcinoma, Papillary; D005260:Female; D006801:Humans; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology*; D060787:Neoplasm Grading; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000235:genetics; D000077273:Thyroid Cancer, Papillary; D013961:Thyroid Gland / Q000473:pathology*; D013964:Thyroid Neoplasms / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology*
chemical_list: D014408:Biomarkers, Tumor
keywords: BRAF V600E; Immunohistochemistry; Low-grade papillary adenocarcinoma; Nasopharynx; Thyroid transcription factor-1