Related Experiment Video
Updated: Jun 8, 2026
Identification of OTX1 and OTX2 As Two Possible Molecular Markers for Sinonasal Carcinomas and Olfactory Neuroblastomas
Published on: February 28, 2019
SMARCB1-Deficient Sinonasal Carcinoma: Case Report and Review of the Literature
Nasser M AlMadan1, Ebtehal A AlEssa2, Doaa A AlGhamdi3
1Department of Dental, Prince Sultan Military Medical City, Riyadh, Saudi Arabia.
Abstract:
BACKGROUND SMARCB1-deficient sinonasal carcinoma is a rare neoplasm with inactivation of the SWI/SNF complex, with an aggressive clinical course as most of the lesions present as advanced in pT3/T4 stages with frequent recurrence, and many patients succumb to the disease. Reported initially in 2014, the lesion has male predominance, with an age range of 19 to 89 years and predilection for the ethmoid sinus and nasal cavity. Histopathological findings show a proliferation of small- to medium-sized monomorphic basaloid cells with indistinctive cytoplasmic borders and round variably prominent nuclei with scattered cells that show rhabdoid morphology. Cytoplasmic vacuoles are common. It has similar morphological findings to a wide array of neoplasms in the sinonasal area. CASE REPORT We report a case of SMARCB1-deficient sinonasal carcinoma in a 30-year-old man referred to our hospital with a preliminary diagnosis of sinonasal adenocarcinoma, intestinal type. Computed tomography showed a huge destructive soft tissue mass in the left maxillary sinus, extended to involve the left nasal cavity with extension to the skull base and perineural spread along the foramen rotundum. Histological examination revealed a malignant basaloid neoplasm embedded in a myxoid stroma that showed loss of SMARCB1 stain. The patient was treated with induction chemotherapy using etoposide and cisplatin for disease control. CONCLUSIONS SMARCB1-deficient sinonasal carcinoma is a rare neoplasm with an aggressive clinical course and high-grade behavior despite having uniform cytological features. This poses complex diagnoses, especially in small biopsies. Incorporating morphological findings with ancillary tests is required to identify this high-grade malignancy.
Insights
SMARCB1-deficient sinonasal carcinoma is a rare, aggressive cancer often diagnosed late. Early identification through combined morphological and ancillary testing is crucial for managing this high-grade malignancy.
Area of Science:
- Oncology
- Pathology
- Genetics
Background:
- SMARCB1-deficient sinonasal carcinoma is a rare neoplasm characterized by SWI/SNF complex inactivation.
- It presents aggressively, often at advanced stages (pT3/T4), with high recurrence rates and mortality.
- The tumor exhibits specific histopathological features, including basaloid cells and rhabdoid morphology, mimicking other sinonasal neoplasms.
Approach:
- A case report detailing a 30-year-old male with SMARCB1-deficient sinonasal carcinoma initially misdiagnosed as adenocarcinoma.
- Diagnostic imaging revealed a large, destructive mass with skull base and perineural spread.
- Histological examination confirmed a basaloid neoplasm with SMARCB1 loss, treated with etoposide and cisplatin chemotherapy.
Key Points:
- This malignancy displays uniform cytological features despite its aggressive clinical course and high-grade behavior.
- Diagnostic challenges arise, particularly with small biopsy samples, due to overlapping morphology with other sinonasal tumors.
- Accurate diagnosis necessitates integrating morphological findings with ancillary testing.
Conclusions:
- SMARCB1-deficient sinonasal carcinoma requires careful diagnostic consideration due to its aggressive nature and potential for misdiagnosis.
- Combined morphological analysis and molecular/immunohistochemical tests are essential for definitive identification.
- Prompt diagnosis and management are critical for improving patient outcomes in this rare cancer.
