Sinonasal tumors with neuroendocrine differentiation are uncommon. They arise from schneiderian epithelium. The authors reported a case in a fifty-six years old female patient who came with complaints of headache and epistaxis. Differential diagnosis and review of literature are presented in detail. This case is presented in view of its rarity.
Sinonasal carcinomas comprise less than 1% of all neoplasms and 3% of those of the upper aero-digestive tract. Primary sinonasal neuro endocrine tumors show a varied histomorphological spectrum ranging from esthesioneuroblastoma (ENB), sinonasal undifferentiated carcinoma (SNUC), sinonasal neuroendocrine carcinoma, and small cell undifferentiated carcinoma. Sinonasal undifferentiated carcinoma is a highly aggressive neoplasm, and it has to be differentiated from less aggressive sinonasal tumors. They differ in their cell of origin, degree of neuroendocrine differentiation and biologic behavior [
Case history: Patient came with complaints of headache since one year, blurring of vision, vertigo, mass over nasal bridge which is hard and tender since two months, and epistaxis since one month. She was a known diabetic and hypertensive. She suffered with right side hemiparesis, recovered after one month. CT scan of paranasal sinuses showed a mass lesion in frontal sinus with extension into bilateral ehmoidal sinuses, left orbit and nasal cavity (
Gross features: We received multiple grey brown bits measuring 2.5 cm × 1.5 cm × 1 cm. And the entire tissue was submitted for histopathology.
Microscopy: Tumor cells are arranged in diffuse sheets with overlying pseudostratified ciliated columnar epithelium. Tumor cells are small in size arranged in sheets with marked pleomorphism; nucleus showed coarse chromatin and prominent nucleoli (
Sinonasal tumors with neuroendocrine differentiation are uncommon tumors with considerable overlap of histological features. Cell of origin may be related to both schneiderian and olfactory epithelia.
Four histologic phenotypes are described [
· Esthesioneuroblastoma (ENB).
· Sinonasal neuroendocrine carcinoma (SNEC).
· Sinonasal undifferentiated carcinoma (SNUC).
· Small cell carcinoma (SmCC).
In this spectrum esthesioneuroblastoma is at the most differentiated end and small cell carcinoma at the least differentiated end.
Sinonasal neuroendocrine carcinoma resides within the less differentiated end of the spectrum of neuroendocrine tumors relative to olfactory neuroblastoma. Sinonasal neuroendocrine carcinoma is a cellular tumor lacking the fibrillary background of olfactory neuroblastoma. Cytologically cells are larger with more cytoplasm, coarse chromatin and larger nucleoli. There can be overlapping of features [
The term sinonasal undifferentiated carcinoma is coined by Frierson to describe a group of undifferentiated, aggressive tumors with no obvious differentiation. Most tumors arise in the nasal cavity and can extend into ethmoid and antra [
Asian and Italian patients but not in other western patients [
Immunohistochemistry; sinonasal neuroendocrine carcinoma is synaptophysin +ve, epithelial membrane antigen +ve where as sinonasal undifferentiated carcinoma is synaptophysin −ve, epithelial membrane antigen +ve. Natural history and biological behaviour varies in this group of tumors. The recommended treatment consists of an aggressive combination of craniofacial resection, adjuvant radiotherapy and chemotherapy. Even then dismal outcomes are common [
In the present case the tumor showed cells with high nuclear cytoplasmic ratio, coarse chromatin, prominent nucleoli, and areas of necrosis. Immunohistochemistry showed negativity for synaptophysin and positivity for EMA. Because there was pleomorphism, areas of necrosis, no neuropil and it was extending into ethmoid sinus it was given “Hyams” grade 4 and “Kadish” stage C (
Histologic criteria | gr1 | gr2 | gr3 | gr4 |
---|---|---|---|---|
Lobular architecture | ++ | + | − | − |
Neuropil | ++ | + | +/− | − |
Rosettes | +/− | +/− | +/− | − |
Necrosis | − | − | + | ++ |
Pleomorphism | − | + | ++ | +++ |
Stage A | Tumor involving nasal cavity |
---|---|
Stage B | Involving paranasal sinuses |
Stage C | Extending beyond sinuses to involve orbit |
Stage D | Metastasis to cervical nodes or distant metastasis |
Finally it was signed out as sinonasal undifferentiated carcinoma, Hyams grade: grade 4, Kadish stage C (