A 44-year-old man presented with a 3-month history of a rapidly growing left-sided nasal mass. He complained of recurrent epistaxis, blocked nose and generalised headaches, concentrated mostly on the left side of his face; however, there were no visual or olfactory disturbances. His medical history included hypertension and previous pulmonary tuberculosis. Nasal endoscopic examination revealed a distended left nostril with a protruding, friable, haemorrhagic, exophytic, foul-smelling mass. The rest of the clinical examination was unremarkable.
Brush cytology of the lesion showed atypical malignant epithelial cells morphologically suggestive of a carcinomatous lesion. Based on the cytological features and radiological imaging, a provisional diagnosis of a Schneiderian papilloma with malignant transformation, sinonasal neuroendocrine carcinoma (SNEC), sinonasal undifferentiated carcinoma (SNUC), sinonasal adenocarcinoma or a malignant salivary gland neoplasm was considered.
Following demonstration of an intracranial component on MRI, a decision was made to treat surgically with a combined rhinology and neurosurgery approach. The intracranial tumour was removed first, followed by a transnasal endoscopic procedure. Histology revealed a SNTCS. Postoperatively, the patient developed a brain abscess with associated seizures and convulsions. The brain abscess was drained, but the patient subsequently demised as a result of rapid disease progression.
A CT scan revealed a soft tissue mass with its epicentre in the left nasal cavity, measuring approximately 89 mm x 30 mm x 46 mm in diameter (anteroposterior x transverse x craniocaudal). Anteriorly, the mass projected through the nostril and posteriorly extended to the posterior choana. Superiorly, the mass extended to the cribriform plate with bony demineralisation. Bulging and demineralisation of the medial wall of the left orbit was present, but no intra-orbital involvement was evident (Figure 1).
The MRI showed a T2 hyperintense, T1 isointense and post-contrast enhancing mass in the left nasal cavity. The nasal septum was deviated to the right, with obstruction of the maxillary sinus. Superiorly, the mass extended into the left anterior cranial fossa and frontal lobe with mild mass effect but no peritumoural oedema (Figures 2 and 3). The lateral ventricles, basal cisterns, cerebellum and brainstem were normal.
At DWI B-1000/mm, the mass showed increased signal. There were areas of susceptibility artefact anteriorly and at the posterior skull base (Figure 4). The axial ADC map showed a lobulated left nasal mass with restricted diffusion and small foci of T2 shine-through, ascribed to small foci of intratumoural cysts or necrosis (Figure 4).
The surgically resected specimen showed a necrotic, friable haemorrhagic tissue mass. Microscopic examination revealed fragments of inflamed sinonasal mucosa with foci of atypical glandular structures, composed of pleomorphic cuboidal to columnar epithelium, demonstrating irregular hyperchromatic nuclei and abundant cytoplasm (Figure 5a). Adjacent to the malignant glands, islands of primitive-appearing round-to-oval immature-appearing cells were noted, morphologically reminiscent of olfactory neuroblastoma, representing the neuroepithelial component (Figure 5b). Mitotic figures and rosette-like structures were present, admixed with numerous islands comprising 'foetal' clear squamous cells (Figure 5c). Osseous and cartilaginous differentiation was absent, but sarcomatous areas were evident, composed of fascicles of pleomorphic spindle cells (Figure 5d).
Immunohistochemical staining revealed a high proliferation index in the atypical glands and primitive round cells. The adenocarcinoma component showed immunoreactivity with cytokeratin AE1 and AE3 (not shown). The primitive neuroepithelium was positive with S100, CD56 and neuron-specific enolase (NSE) (Figure 5f and g), as well as with neuroendocrine markers, synaptophysin and chromogranin (not shown), while the clear-cell squamous cells were immunoreactive to CD99 (not shown). The spindle cell sarcomatous component was positive for smooth muscle markers, desmin and alpha-smooth muscle actin, representing a leiomyosarcoma (Figure 5d and 5h). The immunohistochemical staining pattern and histomorphological features were consistent with the diagnosis of a SNTCS.