Salivary duct carcinoma (SDC) is an uncommon but highly aggressive tumor with a poor prognosis. SDC mainly arises from the major salivary glands, typically the parotid gland. Here, we report a rare case of sinonasal SDC in a 54-year-old male patient that might have originated from the inferior turbinate. The patient presented with left nasal congestion and rhinorrhea. Following an endoscopic intervention, the histopathological examination revealed a diagnosis of SDC, characterized by the formation of solid cancer nests and central comedo-type necrosis. Given the highly aggressive nature and unfavorable prognosis of SDC, it is essential to consider it as a differential diagnosis for unilateral nasal tumors.

UNASSIGNED: NUT carcinoma (NC) is a rapidly progressing and rare neoplasm that primarily affects younger patients and has a survival time of about 1 year. Most of these neoplasms express epithelial markers with no neuroendocrine markers observed. Retrospective studies have shown that pathologists and clinicians do not have a sufficient understanding of the disease due to the lack of common clinical manifestations, imaging, and morphological features.
UNASSIGNED: A 60-year-old female presented at Beijing Friendship Hospital, showing repetitive epistaxis, nasal pain, and nasal congestion with obvious masses in the right nasal sinus and frontal sinus. Microscope analysis revealed two unique morphological changes which have not been previously reported in the existing literature: (I) small spindle cells with sparse cytoplasm and densely stained nuclei and (II) large tumor cells with abundant cytoplasm, some cells resembling plasma cells. The sudden appearance of keratinization was also a prominent feature. Immunohistochemical staining showed differences between the two cell morphologies. Small spindle cells simultaneously expressed CK5/6 and P40, and the Ki67 proliferation index was 40%. The large round cells did not express CK5/6 and P40 but were focal positive for synaptophysin and the Ki67 index was 10%. NUT and P63 were strongly expressed in both cell types and fluorescence in situ hybridization (FISH) revealed BRD4-NUTM1 translocation. Following 20 rounds of postoperative radiation treatment, the patient was alive and no recurrence or metastasis was observed during a 5-month follow-up.
UNASSIGNED: We present novel information from the oldest known and surviving patient of NC originating in the nasal cavity with unique morphological features and different immunohistochemical results. NUT antibody testing should be performed in undifferentiated or poorly differentiated malignancies, particularly those with either or both cytoplasmic vacuolation of medium-sized cells and abrupt keratinization, irrespective of patient age.

Epstein-Barr virus-positive anaplastic plasmacytoma in the sinonasal tract is uncommon. Herein, we present the case of a 40-year-old male patient with a right sinonasal tract filled with a soft tissue mass, as shown on CT. Apart from frequent nosebleeds, he did not report any specific sinonasal symptoms, such as nasal obstruction, discharge, or loss of smell. The patient underwent functional endoscopic sinus surgery under general anesthesia. The diagnosis of Epstein-Barr virus-positive anaplastic plasmacytoma was confirmed by lesion biopsy, subsequent immunohistochemical staining, and in situ hybridization.

OBJECTIVE: Low-grade papillary Schneiderian carcinoma (LGPSC) is a rare and newly described entity of the sinonasal tract. The aim of this study was to evaluate the clinicopathological and molecular characteristics in order to identify typical features for differential diagnosis.
RESULTS: Of the 3000 cases of sinonasal tumour studied during a period of 6 years, five cases were reviewed and diagnosed as LGPSC. All five patients were female (mean age, 47.8 years; range, 18-64 years) and had undergone multiple surgeries (3-10 surgeries). Both the sinonasal tract and the middle ear were involved in four patients. Nodal metastasis occurred in two patients, and one patient developed a distant metastasis to the left lung. Histologically, tumours had branched and crowded papillae with pushing boundaries. Tumour epithelia were multilayered and arranged in an orderly pattern without cilia. No malignant cytological features were observed in any of the cases. Immunohistochemical findings revealed a scattered distribution of Ki67-positive cells and positive staining for epithelial membrane antigen, mainly in the outermost-layer cells. Human papillomavirus (HPV) DNA was found in two patients and genotyped as HPV type 16. Sanger sequencing did not reveal any epidermal growth factor receptor or Kirsten rat sarcoma viral oncogene homologue gene mutation in the five cases.
CONCLUSIONS: We report on five new cases of LGPSC, and confirm LGPSC as a new sinonasal carcinoma that behaves aggressively with metastatic potential. The combination of clinical behaviour and typical histological features can distinguish LGPSC from sinonasal papilloma and other carcinomas.

BACKGROUND: Sinonasal renal cell-like carcinoma (SRCLC) is an extremely rare low malignant tumor arising in the sinonasal tract, with histological mimicry of renal cell carcinoma.
METHODS: We present a case of sinonasal renal cell-like carcinoma in a 63-year-old male patient. Computer tomography(CT) scanning revealed a soft tissue mass at the left nasal cavity and choana. Histologically, the predominant tumor architecture was follicular to glandular with intervening fibrous septa. The tumor cells were uniform cuboidal to polyhedral with abundant clear or eosinophilic cytoplasm. Immunohistochemically, the tumor cells were strongly positive for CK7, EMA, vimentin, SOX10, S-100, and focally positive for CA9. During 6 months of follow-up, there was no clinical or radiological evidence of recurrence or metastasis.
CONCLUSIONS: SRCLC has microscopic features which overlap with tumors that contain clear cells. Thus, several other tumors must be considered in the differential diagnosis of a tumor of the sinonasal region with clear cells, especially metastatic renal clear cell carcinoma. SRCLC is an indolent tumor and none of the reported SRCLC patients had metastatic disease.

OBJECTIVE: Sinonasal tract chondrosarcomas are considered rare malignancies. Few large series evaluated the clinicopathological characteristics of these tumors. The aim of this study was to describe clinical findings, management and outcome of 24 cases of sinonasal tract chondrosarcoma from a single institution and to focus on the validity and advantage of endoscopic technique compared with conventional surgery.
METHODS: A retrospective analysis of clinical information was performed on 24 patients diagnosed as the sinonasal tract chondrosarcomas between 1994 and 2011.
RESULTS: There were 10 males and 14 females (age range, from 7 months to 67 years; mean age, 34.9 years) in this study. The main complaints were nasal obstruction and swelling/mass. The most common affected sites were maxillary sinus and sphenoid sinus. Except one case of myxoid chondrosarcoma and two cases of mesenchymal chondrosarcoma, 17 patients (70.8%) and 4 patients (16.7%) were, respectively, grade I and II. Three patients were misclassified as other tumors at other hospitals. Two cases had a history of radiation. Five cases superimposed upon a preexisting benign bony conditions. Twenty-three of 24 patients were treated with wide surgical excision, including 15 patients with conventional surgeries by external approach and 8 patients with endoscopic surgeries. Local recurrence was observed in 12 patients. The mean interval of recurrence with endoscopic surgery (37.8 months) was longer than conventional approach (21.9 months), but it did not achieve statistical significance due to small sample size. The 5-year disease-specific survival rate was 83.3%.
CONCLUSIONS: Chondrosarcomas of the sinonasal tract are rare. The patients with earlier diagnosis and adequate surgical treatment have a more favorable prognosis. Uncontrollable local disease resulting in compression of adjacent critical structures is the most common cause of death.