Blindness Following Endoscopic Excision of Acinic Cell Carcinoma of Sphenoid Sinus: A Case Report

Abstract

Acinic cell carcinoma (A.C.C.) is a low-grade malignancy involving salivary glands. A.C.C. accounts for only 1–4% of all sinonasal malignancies. We report the case of a 45-year-old female who presented with A.C.C. of paranasal sinus who developed loss of vision after Endoscopic sinus surgery (E.S.S.). Blindness, though rare, is a devastating complication of E.S.S. In this report, the rare occurrence of a papillary cystic variant of A.C.C. in the sphenoid sinus is reported. The causes that may lead to blindness during E.S.S. are analyzed in the absence of direct neural trauma.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-022-03190-2.

Introduction

Acinic cell carcinoma (A.C.C.) is a low-grade neoplasm, constituting 3% of all salivary gland tumors. A.C.C. involving paranasal sinus is uncommon [1, 2]. We present the case of a patient with a papillary-cystic variant of A.C.C. in sphenoid sinus, with left-sided blindness who developed postoperative vision loss in the right eye. Blindness, though rare, is a devastating complication of endoscopic sinus surgery (E.S.S.).

Case Report

A 45-year-old female without any co-morbidities presented with a two-month history of progressive nasal obstruction, intermittent epistaxis, anosmia, and gradual vision loss in the left eye for one month. Nasal endoscopy showed a pinkish mass medial to middle turbinate in the left nasal cavity. The rest of the E.N.T. evaluation was normal. Ophthalmological examination revealed proptosis with no perception of light in the left eye. Fundoscopy revealed, papilledema, temporal pallor, and slight blurring of the optic disc. On the right side, visual acuity was 6/18, with early papilledema, and the patient was complaining of vision deterioration for the past one week. Biochemical parameters and coagulation profile were within normal limits. Metastatic workup was negative. M.R.I. with contrast and Contrast-enhanced Computerised tomography showed a heterogeneous mass lesion of size 56 × 30 × 27 mm with adjacent bony erosion centered around the anterior part of clivus, suprasellar, and para sellar region of the sphenoid sinus with posterior ethmoid sinus extension. Intracranial extradural extension of 7 × 3 mm was present. Invasion of the left optic canal was noted with optic chiasma compression. The left Internal Carotid artery (I.C.A.) was encased partially, and mass was abutting the right I.C.A. with no flow restriction. (Fig. 1) Nasal biopsy suggested the possibility of a papillary-cystic variant of A.C.C. The family was offered the option of surgery or radiotherapy. Considering the better cure rates after surgery and progressively decreasing vision, the family and the patient opted for surgical intervention. After obtaining high-risk consent, including a possibility of risk to life, an Image-guided endoscopic transnasal excision of the tumor was done under general anaesthesia. The tumour was found involving the left nasal cavity, eroding posterior part of the nasal septum, extending to the bilateral sphenoid sinus. The bone of the tuberculum sella, planum sphenoidale, and clival region was partially eroded. The tumor was involving both right and left optic nerves and compressing optic chiasma. A small part of the tumor (5 × 5 mm approximately) found adherent to the right optic nerve sheath was left behind just distal to the orbital apex to preserve vision. Cautery was avoided near the optic nerve to avoid heat injury. Post-procedure, both optic nerves were found to be anatomically intact, without evidence of physical neural trauma (Figure-2). Perioperatively there was no significant hemodynamic instability. Immediately after general anesthesia reversal patient noticed painless loss of vision in the right eye with the absence of light perception. She was immediately started on pulse dose steroid therapy, nasal pack was removed, and nerve inspected. On postoperative day (P.O.D.) 1, bilateral pupils were dilated, and fundoscopy revealed bilateral papilledema. Fundoscopy on P.O.D. 5 revealed resolving papilledema & optic atrophy was seen on P.O.D. 10. Postoperative histopathology confirmed the papillary cystic variant of A.C.C. (Fig. 3). Cells were immunopositive for PanCK. Postoperative VEP (Visual evoked potential) showed absent waveforms in both eyes. Due to the aggressive nature of the tumour and small residual component, postoperative radiotherapy of 30 fractions, 1.8 Gy/fraction in 6weeks was administered. The patient is presently under follow-up with no local recurrence, however, there is no improvement in vision.

Fig. 1.

(a&b)-CEMRI axial & coronal sections showing a heterogeneous mass lesion of size 56 × 30 × 27 mm with adjacent bony erosion centered around the anterior part of clivus, suprasellar and para-sellar region of the sphenoid sinus with Intracranial subdural extension of 7 × 3 mm present. The tumor is partially encasing the left ICA and abutting the right ICA. The tumor is involving the left optic nerve and abutting the right optic nerve

Fig. 3.

Section showing round cells with moderate amount of eosinophilic cytoplasm, hyperchromatic nuclei & indistinct nucleoli and large cystic spaces lined by cuboidal cells with papillary projections exhibiting hobnailing (H&E stain, 100x magnification)

Fig. 2.

(a)Intra- operative picture showing anatomically intact optic nerves and chiasma (Yellow arrow) The green arrow points to the residual lesion on the right optic nerve

(b) fundoscopy image showing optic atrophy in both eyes

Discussion

A.C.C. is a low-grade salivary gland tumour most commonly involving the parotid gland. It rarely occurs in the nose, paranasal sinus, larynx, and lungs [1]. Primary surgery with negative margins is the treatment of choice. Radiotherapy can be considered for high-grade tumours [3]. A.C.C. usually has a 10-year survival rate of 70%. Long-term follow-up is needed, as there is a chance of recurrence or distant metastasis even many years after tumor removal [1]. Loss of vision is a rare but a devastating complication of E.S.S. The overall rate of major complications following E.S.S. is 1–2% [4]. Vision loss may be due to direct or indirect causes. Direct damage occurs around the posterior ethmoid sinus due to the proximity of lamina papyracea and optic nerve. Direct trauma can be due to powered instruments like the microdebrider, drill, thermal damage due to bipolar cautery, or current transmission while using monopolar cautery. Some risk factors, like the presence of onodi cells, can place the optic nerve at even more risk during ethmoidectomy [2, 6]. The optic nerve can be dehiscent in 6% of cases, increasing the chance of injury. Indirect causes for injury are optic nerve compression, vascular compromise to the retina, ischemic optic neuropathy (Anterior and Posterior), cortical infarction, hemorrhage, shock, hypotension, hypothermia, coagulopathies, or embolism [5, 6]. I.C.A. is separated from the sphenoid sinus by a thin plate and maybe dehiscent in 25% of cases. I.C.A. injury can compromise ophthalmic artery blood flow and cause acute vision loss. In our case, compression over the nerve by orbital hematoma or bleeding in sphenoid sinus was excluded both clinically and radiologically. Hemodynamic stability was maintained throughout the surgery, and there was no major bleeding/I.C.A. injury, so a possibility of significantly decreased perfusion to the at-risk optic disc is also less likely. As no ophthalmoplegia was detected, the chance of cavernous sinus pressure symptoms was unlikely. As the nerve was intact, a direct neural trauma was also not probable.

The probable cause could have been due to ischemic optic neuropathy (ION). ION is divided into anterior and posterior ION (AION & PION). They are further divided into arteritic or non-arteritic, based on whether the vessels are affected by giant cell arteritis (G.C.A.) or not [7]. The blood supply of the optic nerve is variable, and commonly the AION is due to the involvement of the posterior ciliary artery. The non-arteritic variety i.e., those not affected by G.C.A., have predisposing factors or have an episode of hypotension leading to ischemia and vision loss [7, 8].

We feel that the tumor manipulation could have caused either spasm or shearing of vessels leading to ischemia and sudden loss of vision. A transient hypotension episode cannot be ruled out totally. The treatment of choice is high-dose steroids, which we administered to our patient, but unfortunately, she did not respond to the treatment. The presence of pressure on the right optic nerve pre-operatively might have put the watershed zone of the optic nerve at relative risk, and the ischemia further caused the terminal event. Optic nerve sheath incision is a possible intervention described as a treatment option in literature [7]. Even though we removed the pack and reinspected the nerve for any signs of compression or hematoma, a sheath incision could have been tried in our patient as a last resort.

This report emphasizes the need to be aware of the possibility of non-traumatic orbital complications in high-risk cases. In centers undertaking skull base surgeries, one should include consent for vision loss routinely in the workup to avoid medicolegal issues.

Conclusion

Invasive pathologies in sphenoid sinus involve the optic nerve early, and even with the best of efforts to avoid trauma, the possibility of vision loss should be considered pre-operatively. Even without direct neural trauma, vascular ischemia, either due to spasm of vessels or transient hypotension, can cause sudden loss of vision. In centers undertaking skull base surgeries, consent for vision loss should be routinely included in the workup to avoid medicolegal issues and also to educate the residents about its possibility.

Electronic Supplementary Material

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Funding

The study did not get any support from any funding organization

Declaration

Conflicts of Interest

There are no conflicts of interest among the authors.

Ethical Considerations

Written informed consent was obtained from the patient.