Clinicopathological Features of Low-Grade Thyroid-like Nasopharyngeal Papillary Adenocarcinoma

Thyroid-like low-grade nasopharyngeal papillary adenocarcinoma: a clinicopathological and molecular study of four cases

Thyroid-like low-grade nasopharyngeal papillary adenocarcinoma (TLLGNPPA) is a rare nasopharyngeal carcinoma. To date, less than 60 cases of TLLGNPPA have been reported, and its clinical features and pathogenesis remain unclear. In this paper, four cases of TLLGNPPA were reported to clarify the clinicopathological and molecular features of this disease. Histopathological examination revealed that all tumors had papillary glandular arrangement, with a fibrovascular axis in the tumor stroma and focal nuclear groove. All tumors expressed pan-CK, CK7, and CK19, while TG and Pax-8 were negative, and the Ki-67 index was approximately 1-3%. The expression of TTF-1 was diffusely positive in two cases and focally positive in two cases. EBER was not expressed in four cases. Molecular testing was possible in three cases. No common driver event was noted, but unique, mutually exclusive molecular variants were found in each of the three tumors (FGFR4, PDK1, AXIN2, FOXL2, and PIK3C3), one also with copy number variants in MCL1 and STMN1. All four patients underwent surgical resection of the tumor and had no metastasis or recurrence from 7 to 60 months post-resection. Given the assertion that these tumors do not recur or metastasize in addition to their heterogeneous gene mutation spectrum, we propose that TLLGNPPA is a neoplasm with low malignant potential and should no longer to be referred to as an adenocarcinoma.

Clinicopathologic characteristics of low-grade thyroid-like nasopharyngeal papillary adenocarcinoma: a case report

Low-grade thyroid-like nasopharyngeal papillary adenocarcinoma is a rare malignant tumor characterized by morphologic analogy to papillary thyroid carcinoma and aberrant thyroid transcription factor-1 (TTF-1) expression. To date, a limited number of cases have been reported in the literature. We report a case of a 20-year-old Chinese male patient with complaints of headaches and nosebleeds for 5 months. The histopathologic examination showed thyroid-like low-grade nasopharyngeal papillary adenocarcinoma that was confirmed by immunohistochemical staining. The patient was treated with macroscopic complete resection without adjuvant therapy. The epidemiologic characteristics and clinical and pathologic features of the disease are summarized. In addition, we summarize the treatments used previously. In general, TL-LGNPPA is a very rare low-grade adenocarcinoma with aberrant expression of TTF-1, and its diagnosis depends on morphology and immunophenotype. The prognosis is good.

Genetic profile identification and clinicopathologic characteristics analysis of the thyroid-like low-grade nasopharyngeal papillary adenocarcinoma

Thyroid-like low-grade nasopharyngeal papillary adenocarcinoma (TL-LGNPPA) is an extremely rare malignancy bearing histomorphological similarities to papillary thyroid carcinoma with good prognosis. It's important to distinguish TL-LGNPPA from other papillary tumors including nasopharyngeal papillary adenocarcinoma (NPPA), metastatic and ectopic papillary thyroid cancer, and metastasized adenocarcinomas, etc. To date, only 48 cases of TL-LGNPPA have been reported in the English literatures. Here, we reported the genomic characteristics of additional 4 cases and reviewed other reports to clarify the clinicopathological features of this tumor. In this study, 41 mutations were detected by whole-exome sequencing, but no typical driver mutations were found. Two sample with Copy Number Variations (CNV) were found (7 q22. 17 q12), of which the segment spanned the regions of RASA4, POLR2J2, SPDYE2, CCL3, CCL4, etc. Additionally, no MSI and HLA LOH were found. To our knowledge, we are the first to reveal the genetic underpinnings of this rare tumor. The clinicopathological features of TL-LGNPPA were characterized, shedding more light on the essential difference between TL-LGNPPA with other papillary tumors.

Thyroid-like low-grade nasopharyngeal papillary adenocarcinoma with squamous differentiation in the posterior nasal septum: A rare case report

RATIONALE

Thyroid-like low-grade nasopharyngeal papillary adenocarcinoma (TL-LGNPPA) is a rare neoplasm characterized by papillary epithelial proliferation and abnormal expression of thyroid transcription factor-1. To our knowledge, squamous differentiation in TL-LGNPPA is an unusual phenomenon, and only 1 case has been reported to date. The tumor occurs mainly on the roof of the nasopharynx. Herein, we report a case of TL-LGNPPA with squamous differentiation located on the posterior nasal septum.

PATIENT CONCERNS

A 45-year-old Chinese women presented to our hospital with a complaint of nasal obstruction for 10 years and the symptom has been getting worse for recent 3 years.

DIAGNOSES

Microscopic examination of the tumor tissue revealed findings typical of TL-LGNPPA, and in addition to the typical components, squamous differentiation could be found in some areas within the fibrovascular cores of the papillary components. Immunohistochemically, the squamous cells were positive for P40 and P63 but negative for thyroid transcription factor-1.

INTERVENTIONS

The patient underwent complete resection of the tumor.

OUTCOMES

Follow up results showed that the patient had no recurrence 41 months after removal of the tumor.

LESSONS

Our report anticipates that, although TL-LGNPPA with squamous differentiation in the posterior nasal septum is rare, this report will expand the existing knowledge associated with TL-LGNPPA.

Cribriform adenocarcinoma of minor salivary glands presented as a nasopharyngeal tumor: A case report highlighting the significance of cytology

Cribriform adenocarcinoma of minor salivary gland (CAMSG) is a rare malignancy presenting cytologic features resembling papillary thyroid carcinoma, localized in the oral cavity and oropharynx. Although cervical lymph node (LN) metastasis is a frequent manifestation of CMSG, there are few publications evaluating its cytology. The aim of this report was to present a CAMSG in an unusual location in the light of cytologic features, thereby enriching the spectrum of fine-needle aspiration biopsy (FNAB) differential diagnosis. We report a case of a 76-year-old woman presenting an enlarged submandibular LN on physical examination. Computed tomography revealed a submucosal lesion situated predominantly in the nasopharynx. FNAB and subsequently an open biopsy of submandibular LN were conducted. In cytologic smear cribriform, dense clusters of monomorphic round-oval tumor cells with scant cytoplasm were observed. Histologically, the tumor was composed of oval, overlapping cells with bright nuclear chromatin and nuclear grooves forming cribriform, papillary, and solid structures. Immunohistochemistry panel revealed the following: TTF-1 (-), thyroglobulin (-), S100 (+), p63 (+), Gal-3 (+), and CK19 (+) focally. The diagnosis of CAMSG should be considered when dealing with nasopharyngeal mass. Commonly, nodal metastases are observed in this tumor; therefore, appropriate evaluation of cytologic smear is crucial for patient management.

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

Purpose

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 blood-stained 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.

Clinicopathological Features of Thyroid-Like Low-Grade Nasopharyngeal Papillary Adenocarcinoma: A Case Report and Review of the Literature

Thyroid-like low-grade nasopharyngeal papillary adenocarcinoma (TL-LGNPPA) is an extremely rare neoplasm of the nasopharynx. Accordingly, its clinical and pathological characteristics are not well-known. We report a case of TL-LGNPPA and review the relevant literature on TL-LGNPPA. A 38-year-old Japanese woman presented with a history of nasal obstruction that had persisted for 1 month after symptoms of a common cold (e.g., low-grade fever, sore throat, and fatigue). A pedunculated tumor of ~20 mm in diameter was found on the posterior edge of the nasal septum. The tumor was endoscopically resected. Based on careful histopathological and immunohistochemical examinations, it was diagnosed as TL-LGNPPA. At 5 years after surgery, the patient remained disease-free. TL-LGNPPA has a very good prognosis, and complete resection with a sufficient safety margin is recommended as the first-line treatment. The morphological characteristics and immunohistochemical findings, especially TTF-1 positivity and thyroglobulin negativity, are important for the diagnosis.

A novel low-grade nasopharyngeal adenocarcinoma characterized by a GOLGB1-BRAF fusion gene

Nasopharyngeal adenocarcinoma is a rare malignancy that is classified into conventional/surface- and salivary-types. Herein we report the case of a 52-year-old male who presented with a right nasopharyngeal mass and right-sided hearing loss. Diagnostic imaging revealed a circumscribed 1.7 cm mass centred in the right antero-lateral aspect of the nasopharynx. A biopsy showed a gland-forming neoplasm that was in continuity with the surface epithelium. The tumor exhibited a nested to micro-papillary architecture, with mild cytologic atypia. Immunohistochemistry demonstrated diffuse staining for CK7, SOX10, and p16; the abluminal layer was highlighted by CK5 and p63, while the luminal cells expressed CD117. The tumor was not amenable to subclassification and was diagnosed as a low-grade nasopharyngeal adenocarcinoma, not otherwise specified (NOS). Subsequent RNA sequencing was performed which identified a novel GOLGB1-BRAF fusion product. Based on its unique morphology and molecular findings, this is presumed to represent a novel subtype of nasopharyngeal adenocarcinoma. In addition to being of diagnostic relevance, this fusion may ultimately represent a potential therapeutic target.

Thyroid-like low-grade nasopharyngeal papillary adenocarcinoma: A case report

INTRODUCTION

Thyroid-like low-grade nasopharyngeal papillary adenocarcinoma (TL-LGNPPA) is a rare neoplasm characterized by morphological analogy to papillary thyroid carcinoma and the abnormal expression of thyroid transcription factor-1 (TTF-1). We herein report a rare case of TL-LGNPPA with a review of its clinical and morphological characteristics and the treatment provided.

PATIENT CONCERNS AND DIAGNOSIS

The patient was a 50-year-old Chinese woman with the complaint of a three-year history of phlegm with blood with pharyngeal discomfort. There were no remarkable physical findings, and the laboratory tests were normal. Laryngoscopy and nasal computed tomography identified a mass at the posterior end of the nasal septum. Histologically, the tumor exhibited an oval papillary growth. Immunohistochemically, the neoplastic cells were positive for TTF-1, vimentin, cytokeratin 7, and cytokeratin 19. Pathological examination indicated a thyroid-like low-grade nasopharyngeal papillary adenocarcinoma.

INTERVENTION

The neoplasm was completely resected without any complication.

OUTCOMES

The patient had neither local recurrence nor distant metastasis 1 year after the removal of the tumor.

CONCLUSION

Although TL-LGNPPA is a malignant tumor, complete surgical resection is an effective treatment.

Clinicopathologic Characteristics of Thyroid-like Low-grade Nasopharyngeal Papillary Adenocarcinoma: A Case Report

Thyroid-like low-grade nasopharyngeal papillary adenocarcinoma (TL-LGNPPA) is an extremely rare neoplasm. It morphologically resembles papillary thyroid carcinoma and is immunochemically positive for thyroid transcription factor 1. Herein, we reported a case of TL-LGNPPA in a female patient of 35 years old. She felt pharyngeal foreign body sensation of unknown cause and subsequently developed dyspnea after activities. Nasopharyngeal plain computerized tomography showed no abnormalities, but laryngoscopy showed a peanut-sized smooth neoplasm with a pedicel at the posterior edge of the nasal septum. The mass was completely resected by nasopharyngoscopy. Histologic examination showed the tumor was composed of papillary configuration and tubular glands; each papilla was covered with cuboidal or columnar epithelial cells; tubular architecture and spindle cell component were also observed; some tumor cells had psammoma bodies. Immunohistochemically, tumor cells were positive for CKpan, CK7, CK19, VIM, and thyroid transcription factor 1, but negative for thyroglobulin, CK20, S-100, P63, P40, smooth muscle actin, CDX-2, and glial fibrillary acidic protein. This patient was diagnosed with TL-LGNPPA and followed up for 16 months, and metastasis and recurrence were not observed.

Biphasic Thyroid-Like Low-Grade Nasopharyngeal Papillary Adenocarcinoma with a Prominent Spindle Cell Component: A Case Report

Thyroid-like low-grade nasopharyngeal papillary adenocarcinoma (TLLG-NPPA) is a distinctly rare malignancy of the nasopharynx. Morphologically and immunophenotypically, TLLG-NPPA resembles papillary thyroid carcinoma (PTC) and is characterized by a papillary architecture with PTC-like nuclear features and thyroid transcription factor-1 expression. Recently, some cases of TLLG-NPPA with a spindle cell component have been reported. In this study, we report a very interesting case of biphasic TLLG-NPPA that was predominantly composed of spindle cells, with comprehensive analyses of its clinical, pathological, and immunophenotypical features. A 50-year-old woman presented with a sensation of a foreign body in the nasopharynx. Nasopharyngoscopy and computed tomography demonstrated a pedunculated mass arising from the nasopharyngeal roof. Based on the clinical impression of a nasopharyngeal tumor, an excisional biopsy was performed. At low-power magnification, the nasopharyngeal mass consisted of papillary tumor tissue, the growth pattern and architecture of which resembled those of PTC. The papillae were complex and packed tightly with fibrovascular cores. At high-power magnification, each papillary structure was lined with a pseudostratified cuboidal-to-columnar epithelium. The tumor cell nuclei frequently showed a ground-glass appearance, intranuclear grooves, pseudoinclusions, and membrane thickening and irregularity, resembling the characteristic nuclear morphology of PTC. These histological features were compatible with TLLG-NPPA. Intriguingly, in between the papillary components were spindle cells that appeared very similar to the glandular epithelial cells that imperceptibly merged with the papillary component. This spindle cell component comprised two-thirds of the entire tumor volume. The nuclear morphology of the spindle cell component was similar to that of the papillary component. On immunostaining, both the papillary and spindle cell components were diffusely and strongly positive for thyroid transcription factor-1, cytokeratin 7, cytokeratin 19, vimentin, and Hector Battifora mesothelial-1. In contrast, the tumor cells tested negative for p63, p40, smooth muscle actin, S-100, cytokeratin 5/6, thyroglobulin, BRAF V600E, and Epstein–Barr virus-encoded small RNAs. Only two cases of biphasic TLLG-NPPA exhibiting a prominent spindle cell component had been reported previously in the English literature. When the pathologist receives a primary nasopharyngeal mass with the aforementioned histological features, particularly biopsy specimens with predominant spindle cells, biphasic TLLG-NPPA should be considered in the differential diagnosis. By describing its detailed clinicopathological characteristics, we anticipate that this report will expand the existing knowledge on the spindle cell component associated with TLLG-NPPA.

Primary papillary epithelial tumour of the sella: expanding the spectrum of TTF-1-positive sellar lesions

AIM

To describe four novel primary epithelial tumours of the sella with papillary architecture and Thyroid Transcription Factor 1 (TTF-1) expression.

METHODS

Paraffin-embedded tissue from the four cases and recurrence of patient 1 was investigated with haematoxylin-eosin, special histochemical stains, immunohistochemistry with a broad panel of antibodies and next-generation sequencing. The ultrastructure of one tumour was studied in tissue retrieved from paraffin.

RESULTS

The lesions occurred in three females aged 20, 26 and 42 years and a male aged 49 years. They presented with signs and symptoms secondary to pituitary stalk compression. Preoperative neuroimaging documented mixed solid and cystic, enhancing sellar masses with suprasellar extension. Histologically, the tumours showed thin papillae lined by a single layer of cytokeratin and TTF-1-positive cuboidal and cylindrical cells with mildly atypical nucleus. Next-generation sequencing performed in three cases did not identify any mutations. The main differential diagnosis included metastasis from lung or thyroid carcinoma, extraventricular choroid plexus papilloma and sellar ependymoma.

CONCLUSION

We suggest the descriptive term of primary papillary epithelial tumour of the sella (PPETS) for this entity and propose that it could represent the intracranial equivalent of thyroid-like low-grade nasopharyngeal papillary adenocarcinoma. The cell of origin of PPETS remains undetermined although the intense and ubiquitous expression of TTF-1 may suggest a derivation from the infundibulum or ventricular recess. Our study expands the spectrum of sellar TTF-1-positive tumour and challenges the view that they all derive from pituicytes.

Thyroid-Like Low-Grade Nasopharyngeal Papillary Adenocarcinoma with Biphasic Histology

Thyroid-like low-grade nasopharyngeal papillary adenocarcinoma (TL-LGNPPA) is a rare primary adenocarcinoma of nasopharynx. The immunohistochemical pattern of this tumor is similar to that of papillary thyroid carcinoma making this neoplasm a challenging diagnosis. A case of TL-LGNPPA with biphasic morphology is presented. The removed tumor from the nasopharynx exhibited a polypoid appearance. Microscopically, it was composed of papillary structures admixed with a few solid areas of spindle cells. The papillae were lined by columnar epithelium. Both the epithelium and the spindle cells were strongly positive for TTF-1 and CK19 and negative for CK5/6, S-100, and thyroglobulin. Cellular atypia, necrosis, and high mitotic rate were absent. Ki67 was less than 2% in the neoplastic cells. No local recurrence or distant metastasis was reported after 12 months of follow-up. Caution should be taken to differentiate TL-LGPPA from other TTF-1-positive neoplasms, especially papillary thyroid carcinoma, as the prognosis for these two tumors is entirely different.

Thyroid-Like Low-Grade Nasopharyngeal Papillary Adenocarcinoma

OBJECTIVES

Thyroid-like low-grade nasopharyngeal papillary adenocarcinoma (TLLGNPPA) is a relatively rare nasopharyngeal tumor. We performed morphological characterization, immunohistochemical profiling, and investigated gene mutations. We also provide clinical follow-up data and brief review of the literature.

METHODS

Immunohistochemistry was used to evaluate the expression of TTF-1, CK19, CK7, EMA, TG, Pax-8, CK5/6, S100, and Ki-67. Additionally, in situ hybridization was utilized to identify the presence of EBV. We investigated mutations in hot-spot exons of KRAS/NRAS/BRAF to rule out common mutations seen in thyroid tumors.

RESULTS

Histopathologic examination of four cases identified tumors that were mainly occupied by papillary architectures. One case had a predominantly glandular structure. The tumors expressed TTF-1 and CK19, while TG and Pax-8 were negative. S100 was moderately expressed focally in three cases.

CONCLUSIONS

While TLLGNPPA displays a morphological resemblance to papillary thyroid carcinoma (PTC), it is vital to differentiate nasopharyngeal metastasis from PTC for appropriate treatment.

Thyroid-like low-grade papillary adenocarcinoma of nasopharynx

We report a 35-year-old woman with complaints of nasal obstruction and mild post-nasal drip for 6 months. She did not improve with medical treatment. Clinical examination had no positive finding. She was evaluated with a CT scan and MRI that revealed a polypoid mass lesion in nasopharynx without any adhesion to adjacent tissue. Endoscopic examination of nasopharynx revealed an exophytic nasopharyngeal mass in anterior wall of nasopharynx that complete macroscopic transnasal endoscopic resection was performed. The histopathological examination reported thyroid-like low-grade nasopharyngeal papillary adenocarcinoma that was confirmed on immunohistochemical staining. After complete macroscopic resection of the mass, patient was regularly followed-up for 6 years and there was no evidence of recurrence. This example has the educational tips of the optimal therapeutic strategies for primary nasopharyngeal adenocarcinomas with long follow-up.

[The specific immunophenotypic features of nasopharyngeal carcinoma]

We have undertaken the retrospective analysis of the medical histories of 119 patients presenting with nasopharyngeal carcinoma (NPC) and the biopsy specimens obtained from them; the wereinvestigated with the use of the histological (staining of the micropreparations with hematoxylin and eosin) and immunehistochemical (monoclonal murine antibodies against Pan-cytokeratin, CK 5/6, EBV, CK7, CK19, p16) techniques. The study has demonstrated the presence of non-differentiated nasopharyngeal carcinoma in 97 patients, diffuse large-cell B-lymphoma in 18 ones, melanoma of the nasopharyngeal mucous membrane in 2, and nasopharyngeal rhabdosarcoma in 1 patient. The immunohistochemical study revealed co-expression of the markers of Epstein-Barr virus, Pan-cytokeratin, and CK 5/6 in the non-differentiated nasopharyngeal carcinoma .

Nasopharyngeal Papillary Adenocarcinoma as a Second Head and Neck Malignancy

Nasopharyngeal adenocarcinomas are rare tumours, and include neoplasms arising from the nasopharyngeal surface epithelium as well as those of minor salivary gland origin, each of which is distinct from the other. The former encompasses nasopharyngeal papillary adenocarcinoma (NPAC), also known as low grade NPAC and thyroid-like NPAC, an extremely unusual malignancy bearing histomorphological similarity to papillary thyroid carcinoma, and displaying indolent clinical behaviour. We report the case of a 41-year-old lady who developed NPAC as a second malignancy five-and-a-half years after being diagnosed and treated for a diffuse astrocytoma in the frontal lobe. In addition, we discuss the differential diagnosis, as well as raise certain pathogenetic considerations with regard to this unique neoplasm.

Primary thyroid-like low-grade nasopharyngeal papillary adenocarcinoma: A case report and literature review

RATIONALE

Primary thyroid-like low-grade nasopharyngeal papillary adenocarcinoma (TL-LGNPPA) is an extremely rare malignant nasopharyngeal tumor with features resembling papillary thyroid carcinoma including nuclear positive expression of thyroid transcription factor-1 (TTF-1).

PATIENT CONCERNS

A 64-year-old male presented with nasal bleeding and a foreign body sensation of the nasopharynx. Laryngoscopy revealed a 2.0-cm broad-based mass with a smooth surface on the posterior wall of the nasopharynx. A biopsy was obtained.

DIAGNOSES

Histopathologic examination demonstrated tumor cells arranged in both papillary and glandular architecture. The tumor cells express nuclear immunoreactivity for TTF-1. The diagnosis of TL-LGNPPA was made.

INTERVENTIONS

After the patient was diagnosed with TL-LGNPPA, he underwent complete surgical resection.

OUTCOMES

There was no recurrence or evidence of metastatic disease at the 12-month follow-up.

LESSONS

TL-LGNPPA is easy to misdiagnose as metastatic papillary thyroid carcinoma or other relative primary adenocarcinomas. It is important to have a broad differential diagnosis and know the key features of each entity because the prognosis and clinical treatment of each may differ.

Thyroid-like low-grade nasopharyngeal papillary adenocarcinoma with squamous differentiation: a novel histological finding

Thyroid-like low-grade nasopharyngeal papillary adenocarcinoma (TL-LGNPPA) is an extremely rare neoplasm originating from the nasopharyngeal surface epithelium. Histopathologically, TL-LGNPPA is characterized by cuboidal/columnar tumor cells forming papillary fronds and thyroid transcription factor-1 (TTF-1) expression resembling papillary thyroid carcinoma. To date, the recorded histological features of TL-LGNPPA have been almost uniform, and the range of histological variations in this tumor type has not been sufficiently understood. Here, we report on a 68-year-old man with TL-LGNPPA. Microscopic examination of the resected tumor revealed findings typical of papillary adenocarcinoma of this type, and moreover, this case showed scattered squamous cell foci as a hitherto unreported finding. The squamous cells showed no obvious nuclear atypia or proliferating activity, and their presence was similar to the "squamous metaplasia" of papillary thyroid carcinoma. Immunohistochemically, p40 and TTF-1 coexpression was observed in the squamous cell nuclei, indicating their origin from the glandular tumor cells of TL-LGNPPA.