Nasopharyngeal papillary adenocarcinoma harboring a fusion of ROS1 with GOPC

Abstract

Rationale: Nasopharyngeal papillary adenocarcinoma is a region-specific tumor originating from the nasopharyngeal surface epithelium. Owing to its rarity, more attention has been paid to its clinicopathologic features, while little effort has been made to study the gene abnormalities that drive this tumor. We describe the first case of nasopharyngeal papillary adenocarcinoma harboring a fusion of ROS1 with GOPC. Patient concerns: A 22-year-old female patient was diagnosed with nasopharyngeal papillary adenocarcinoma in our hospital, and she had right nasal obstruction for more than 6 months. Nasal endoscopy revealed a mass on the posterior roof of the nasopharynx. Diagnoses: Immunohistochemical staining showed that the tumor cells were diffusely positive for transcription termination factor 1, vimentin, CK19, glypican-3, and CK7, and negative for melanocyte, CK5/6, CK20, P53, P63, S100, smooth muscle actin, p16, PAX8, and thyroglobulin. The Ki-67 index was approximately 5%; EBV-encoded small nuclear RNA was negative. Interventions: The tumor was completely excised on endoscopy with a negative surgical margin. Outcomes: No sign of recurrence was observed during the 3-year follow-up period. Lessons: Owing to its rarity, pathologists should be aware of this unusual neoplasm to avoid misdiagnosis. Further studies are needed to further characterize the relationship between ROS1-GOPC fusion and the pathogenesis of this carcinoma and its response to tyrosine kinase inhibitors in relapsed cases.

Nasopharyngeal Papillary Adenocarcinoma; Two Cases And Review of the Literature

“…Although the tumor is histomorphologically very similar to thyriod papillary carcinoma (TPC) and expresses TTF-1, it can be clearly differentiated from TPC immunohistochemically by being thyroglobulin and Napsin-A negative. [1,3,4,6] Our cases showed strong TTF-1 and CK7 expression, and in addition, Case 2 also showed focal S100, p63, and p40 expression. Although thyroglobulin is almost…”

“…[8] In addition to the positivity of TTF-1, the negativity of CK20 and CDX2 distinguishes it from intestinal-type adenocarcinoma. [6,7] The molecular genetic studies showed no mutation in the BRAF and KIT gene, RT-PCR and FISH assays were negative for SYT-SSX1/2 fusion transcripts and SYT (18q11.2) gene rearrangement. [1,3] Similar to the examples in the literature.…”

“…[1,3] Similar to the examples in the literature. [1,6] No results regarding the relationship of the tumor with EBV and HPV have been reported. [5,6] In situ hybridization of EBV and HPV and FISH for ALK and ROS1 was negative in both of our cases.…”

“…It has been defined that NPAC, which has distinctive histological features, shows TTF-1 expression immunohistochemically. [1][2][3][4][5][6][7][8][9][10] No difference was found in the incidence between genders. [4,9] Although it is frequently seen on the posterior and lateral nasopharynx wall and roof of the nasopharynx, the nasal septum is also seen.…”

“…[4,9] Although it is frequently seen on the posterior and lateral nasopharynx wall and roof of the nasopharynx, the nasal septum is also seen. [2][3][4][5][6][7][8][9][10] Patients usually present with nasal fullness, congestion, or nosebleeds. [5] NPAC has a good prognosis and local excision is considered sufficient in its treatment.…”