Acute bilateral retrobulbar optic neuritis revealing sphenoethmoidal sinus neuroendocrine carcinoma
Belfaiza Soukaina, Marion Chatain, Benjelloul Fatiha
Department of Ophthalmology, Nord Franche-Comté Hospital, Besançon, France
Correspondence Address:
Dr. Belfaiza Soukaina
University Medicine of Franche-Comte in Besancon, Besancon
France
Source of Support: None, Conflict of Interest: None
DOI: 10.4103/injms.injms_130_22
Primary sinonasal neuroendocrine carcinoma is a rare tumor of extreme malignancy. The diagnosis is often made at an advanced stage. The most recently documented treatment for nonmetastatic paranasal sinus neuroendocrine carcinoma consists of chemotherapy (cisplatin-VP16) followed by radiotherapy. Surgery is reserved for resectable tumors that do not respond well to chemotherapy. We report the case of a patient admitted for acute bilateral Retrobulbular optic neuropathy (RBON) revealing a sphenoethmoidal sinus neuroendocrine carcinoma.
Keywords: Acute bilateral retrobulbar optic neuritis, radiotherapy, sphenoethmoidal sinus neuroendocrine
Primary sinonasal neuroendocrine carcinoma is a rare tumor of extreme malignancy, characterized by its rapid growth, metastatic potential, and poor prognosis. The diagnosis is often made at an advanced stage. We report the case of a patient admitted for acute bilateral retrobulbar optic neuropathy (NORB) revealing a sphenoethmoidal sinus neuroendocrine carcinoma.
Case reportWe report the case of a 50-year-old patient, a chronic smoker, who presented to the emergency department with a 10-day history of decreased vision in both eyes. The best-corrected visual acuities were “counting fingers” in both eyes with a bilateral relative afferent pupillary defect. Slit-lamp examination was otherwise normal [Figure 1]. Retrobulbar optic neuritis was presumed and an orbito-cerebral magnetic resonance imaging (MRI) revealed a posterior sphenoethmoidal mass extending to the cribriform plate. The mass was hypointense on T1-weighted images and moderately hyperintense on T2-weighted images. The lesion showed dense homogeneous enhancement after contrast administration. A dural thickening was observed next to the lesion [Figure 2], [Figure 3], [Figure 4]. The patient underwent a sphenoidotomy which revealed a huge tumor and several biopsies were performed. Immunohistological examination showed a poorly differentiated neuroendocrine carcinoma of the sphenoethmoidal sinuses. Based on this evaluation, the patient was given oral corticosteroids and then received fractionated stereotactic radiotherapy with a total dose of 60 Gy in combination with chemotherapy. On examination 1 month after radiotherapy, the visual acuity rises to 1/20 in the right eye and 5/10 in the left eye according to the Snellen scale.
Figure 1: The fundus of the right eye (a) and the left eye (b) was normalFigure 2: MRI axial brain T2 found a posterior sphenoethmoidal tumor (arrow) with extension to the cribriform plate and infiltration of the right optic nerve. MRI: Magnetic resonance imagingFigure 3: MRI axial brain T2 found a posterior sphenoethmoidal tumor (arrow) with extension to the cribriform plate and infiltration of the left optic nerve. MRI: Magnetic resonance imagingFigure 4: MRI brain coronal T1 found a posterior sphenoethmoidal tumor (arrow). MRI: Magnetic resonance imaging DiscussionNasosinus cancers represent 0.2%–0.8% of all malignant tumors.[1] The maxillary sinus is the most common primary site, affected in 60% of cases. Sphenoethmoidal sinus neuroendocrine carcinoma represents only 1% of cases.[2] The sphenoid sinus neuroendocrine carcinoma is a highly malignant tumor that develops from the Schneiderian epithelium of the nasal cavity and paranasal sinuses.[2],[3] It is a rare and very aggressive tumor. Some risk factors have been reported including smoking, exposure to heavy metals, wood, and a history of irradiation.[2],[3] The initial clinical symptomatology is often similar to that of benign sinus involvement, which leads to late diagnosis in advanced stages.[3] However, due to the rapid progression of the disease, the clinical signs evolve rapidly with the presence of epistaxis, ptosis, or paralysis of the cranial nerve.[3] The carcinomas of the sphenoid sinus can manifest with ophthalmological signs, in particular, oculomotor paralysis, orbitopathy, and retrobulbar optic neuritis.[3] These signs are explained by the close anatomical relationships between the sphenoid sinus, the cavernous sinus, and the orbit. Nasosinus neuroendocrine carcinoma imaging is nonspecific. Computed tomography (CT) scan is the ideal examination to specify bone damage. It is that of an invasive and aggressive mass with bone lysis on CT scan, an intermediate signal on T2, and perineural involvement.[4] MRI remains superior in delimiting the extent of the tumor, the perineural, and meningeal extension.[4] The diagnosis is based on histological analysis and immunohistochemical study.[5] The neuroendocrine markers (SYN, P63, CK5 6, CD56, BCL2, and EMA) are usually positive.[5]
There is no specific treatment recommendation for primary sinonasal neuroendocrine carcinoma. Therapeutic modalities are dictated by tumor size and clinical stage. Previously, it consisted of surgical resection followed by radiation or chemotherapy.[5] Chemotherapy combined with radiation, with or without surgery, has been recommended since the 1990s.[5] The current treatment is chemotherapy (cisplatin-VP16) in two cycles followed by different options according to the case. In case of a poor response to the first chemotherapy, surgery is the preferred treatment for resectable tumors, followed by radiation therapy (68 Gy) and postoperative chemotherapy. There is still no consensus about a palliative therapeutic approach for metastatic paranasal sinus cancers. However, chemotherapy appears to be the best option and may be followed by palliative radiation therapy.[5] Metabolic radiotherapy with somatostatin or peptide receptor radionuclide therapy appears to be safe and effective in the treatment of metastatic neuroendocrine tumors but its effectiveness is also debated in the treatment of sinonasal neuroendocrine carcinoma.[6] Despite aggressive treatment, the prognosis of sinonasal neuroendocrine carcinoma is bleak. Five-year survival is 15%[7] and local recurrences of sinonasal neuroendocrine carcinoma occur frequently.[7]
ConclusionSinonasal neuroendocrine carcinoma is an extremely aggressive tumor. It is often diagnosed at a late stage and it is rarely revealed by bilateral retrobulbar optic neuritis as in our case. The most recently documented treatment for nonmetastatic paranasal sinus neuroendocrine carcinoma consists of chemotherapy (cisplatin-VP16) followed by radiation therapy. Surgery is reserved for resectable tumors that do not respond well to chemotherapy.
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The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understands that his name and initials will not be published and due efforts will be made to conceal his identity, but anonymity cannot be guaranteed.
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Conflicts of interest
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