Low-Grade Nasopharyngeal Papillary Adenocarcinoma: A Review of 28 Patients in a Single Institution

Abstract

Low-grade nasopharyngeal papillary adenocarcinoma (LGNPPA) is a rare nasopharyngeal tumor. This study aimed to analyze the clinical and histopathological features of the disease, and to share our experience of its treatment. Patients and Methods: We collected demographic data, clinical symptoms, tumor location, pathological features, immunohistochemical results, treatments, and outcomes of 28 patients with pathologically confirmed LGNPPA between 2009 and 2019. Results: The median age of the 28 patients was 41.5 years, with a female: male ratio of 1.5:1 (17 females, 11 males). The most common symptom was bloodstained rhinorrhea. The neoplasms were located on the roof of the nasopharynx (RON) in 13 patients, the posterior margin of the nasal septum (PMONP) in 12 patients, the lateral wall of the nasopharynx in one case, and both the RON and PMONP in two patients. Fourteen patients were diagnosed with thyroid-like LGNPPA. Immunohistochemically, the tumors were uniformly positive for cytokeratin 7, cytokeratin 8, vimentin, epithelial membrane antigen, and pan-cytokeratin, and negative for thyroglobulin. Twenty-three patients underwent pure endoscopic surgery, three patients underwent preoperative radiotherapy, and two patients underwent radiotherapy postoperatively. All patients were alive without evidence of lymphatic or distant metastases in the follow-up period (range: 7 to 121 months). Two patients (7%, 2/28) experienced disease recurrence. Conclusion: LGNPPA is an indolent tumor with an excellent prognosis. Endonasal endoscopic excision was an effective treatment. It is important to distinguish thyroid-like LGNPPA from metastatic papillary thyroid carcinoma because these diseases have similar microscopic features but different prognoses.

An Extremely Rare Nasopharyngeal Malignant Tumor: A Case Report

“…NPAC may appear in any part of the nasopharynx, but it most commonly involves the roof, the lateral, and the posterior wall [ 4 ]. It presents as a soft, slow-growing exophytic mass with a papillary or polypoid appearance.…”

“…Nasal obstruction is the most common manifestation [ 1 , 3 ]. Only a limited number of cases of NPACs has been reported in the literature because these neoplasms are extremely rare [ 4 , 5 ]. As clinical presentation could be easily underestimated, an index of suspicion is necessary for a timely diagnostic and therapeutic intervention.…”

A rare case of low-grade nasopharyngeal papillary adenocarcinoma in a young adult woman: A case report from a tertiary hospital in Northwestern Nigeria

“…Complete surgical excision has been considered the treatment of choice for most cases of NPAC. [ 1 4 6 8 9 10 11 ] In their study, Takakura et al [ 10 ] found out that among the 28 case reports of NPAC they reviewed, all cases were treated with complete resection and without adjuvant treatment. Endoscopic surgery was performed in 16 cases (57.1%).…”

“…Though controversy exists regarding the optimal treatment due to the rarity of this tumour,[ 8 ] complete surgical excision, with or without the aid of endoscope, has been considered the treatment of choice for most cases of NPAC. [ 1 4 6 8 9 10 11 ]…”

Efficacy of endoscopic resection and intensity-modulated radiotherapy for thyroid-like low-grade nasopharyngeal papillary adenocarcinoma: a case report

“…Lowgrade nasopharyngeal papillary adenocarcinoma (LGNPPA) is extremely rare among nasopharyngeal neoplasms. To our knowledge, fewer than 70 cases have been publicly reported thus far (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19). Because of the very low incidence of this disease, there are no guidelines or protocols developed for proper, standardized therapy.…”