Fronto Ethmoidal Mucocele Associated with Type 4 Kuhn Cells

Abstract

A mucocele is an epithelial lined mucous containing sac completely filling the sinus and capable of expansion. We report a case with unilateral frontoethmoidal mucocele in relation with type IV Kuhn cell. A 26 year old man came to the ENT department at SDUMC, Tamaka, Kolar, presenting complaints of proptosis of left eye since 3 years. After detailed examination and investigations patient was Diagnosed to have mucocele of left frontoethmoidal region. Intraoperatively we found a rare picture of type IV kuhn cells completely seated in the frontal sinus. After externally assisted modified Lothrop’s approach, marsupialization of mucocele was done in the nasal cavity and symptoms of the patient relieved. We state that, in cases of frontoethmoidal mucocele, externally assisted modified Lothrop procedure offers an alternative for endoscopic management of frontoethmoidal mucocele for the complete clearance of disease.

Introduction

A Mucocele is an epithelial lined mucous containing sac completely filling the sinus and capable of expansion [1]. All paranasal sinuses can develop a Mucocele. But, frontal and ethmoidal sinuses being the ones most commonly affected, with 60% and 30% respectively, and maxillary sinus with 10%. Sphenoid sinus occurs very rarely [2]. Accumulation of mucous can increase the pressure resulting in atrophy or erosion of bones of sinus wall, permitting the Mucocele to expand in the path of least resistance, like in orbit, adjacent sinuses, nasal cavity or skin [3]. Frontal Mucocele may present with ophthalmic disturbance, they can intrude on the orbit with ocular displacement and proptosis. These are the common causes of long standing proptosis [4]. A frontal cell is a common analog that can become the cause for chronic frontal sinusitis.

There are four frontal variations which have been classified as the following:

Type I Single cell seen in coronal CT scan above the Agger nasi cell.

Type II Is a tier of cells in frontal recess above Agger nasi cell.

Type III is a single massive cell pneumatizing cephal head into frontal sinus.

Type IV Is a single isolated cell within the frontal sinus [5].

We report a case with unilateral frontoethmoidal Mucocele in relation with type IV Kuhn cell.

Case Report

A 26 year old man came to the ENT department at SDUMC, Tamaka, Kolar, presenting complaints of proptosis of the left eye over the past 3 years. He had previous history of nasal block 9 years ago for which he underwent surgery. After 1 year of his complaints and then he had recurrence of the disease for which he underwent surgery again 5 years back. The patient also gives history of decreased visual acquity. Upon examination there was downward and outward displacemnt of the left eye globe (Fig. 1). The anterior rhinoscopy showed no significant findings. The Diagnostic Nasal Endoscopy revielead an expansive lesion involving the upper part of nasal cavity and multiple adhesions in left nasal cavity. Contrast enhanced computed tomography of paranasal sinus showed left supraorbital isodense mass causing gross downward and outward displacement of the left eye globe. Frontal recess apperared to be patent, the mucocele was involving the complete frontal and ethmoidal sinus on the left side (Fig. 2). The patient was taken for surgery after all relevant investigations and preanaesthetic evaluation. spectacle incision was given (Fig. 3), and the anterior table of the frontal sinus was exposed. After exposure we noticed two single isolated cells found within each frontal sinus (Fig. 4) completely involving the medial aspect the sinus. On external approach mucocele involving the lateral most portion of frontal sinus and the supraorbital cells were clearly seen. On palpation the frontal cells were firm to hard in consistency, which was difficult to fracture with thumb pressure. There was a deficiency noticed in the superior and medial aspect of the orbit. Complete mucocele excision was done through external approach and marsupialized in the nasal cavity. In addition to that through external approach the floor of the frontal sinus was widely opened from lamina papyracea to the nasal septum-Draf 2b was done (Fig. 5). A gel foam was placed in the frontal sinus followed by nasal packing and the external wound was closed in layers. The Nasal pack removed after 48 h and the post op diagnostic nasal endoscope performed after 3 weeks and shows proper clearance of disease (Fig. 6). At 5 months of post operative period the proptosis has completely resolved and but there is a residual inferior globe displacement of 1 cm (Fig. 7). His ocular movements returned to normal with no complaints of diplopia.

Fig. 1.

Forward and downward displacement of left eye

Fig. 2.

CECT of PNS showing mucocele involving ethmoids frontal and downward displacement of supraorbital region

Fig. 3.

Spectacle incision for external approach

Fig. 4.

Type 4 khun cells

Fig. 5.

Frontal osteoplastic flap replaced, complete clearance of disease with modified Lothrop’s approach

Fig. 6.

Post op 21 days showing patency of frontal sinuses

Fig. 7.

Post op 5 months showing repositioning of eye globe

Discussion

Langenback described mucoceles of paranasal sinuses in 1820. In 1907, Turner wrote a comprehensive account of mucocele. The name mucocele was coined my Rollet in 1909. Lambert described frontoethmoidal mucocele as the most common nasal condition to cause proptosis [4]. Gerber in 1909 suggested that pre-existing catarrh was one cause of chronic inflammatory changes in the sinuses which led to a temporary or permanent obstruction of the ostium, followed by a accumulation of mucus within the cavity and secondary expansion and absorption of the bony walls. In 1921 Howarth states that preexisting trauma to the orbit or nose might be a significant factor in the pathogenesis of the condition, although there might be a considerable time interval, varying from months to years from traumatic to onset of proptosis [4]. Mucoceles are relatively rare sinus pathologies. Frontoethmoidal mucocele is the most common site of distribution of mucocele [5]. Treatment of mucocele is surgical. A number of treatment options are available and the choice depends on the degree of expansion of mucocele [6, 7]. In 1914 Lothrop’s described that intranasal ethmoidectomy followed by external lynch-type approach with resection of the medial frontal sinus floor, superior nasal septum and intersinus septum forms a large frontonasal communication. His report states that as intranasl approach of this technique is too dangerous with lack of adequate visualization. There fore external approach allowed medial collapse of orbital soft tissue following stenosis of frontonasal communication [8].

Conclusion

With the advent of externally assisted endoscopic modified Lothrop’s approach, we believe that it is easy to introduce and endoscope with clear visualbility and marsupialization through nasal cavity of the mucocele, the lateral bony wall was preserved and medial collapse does not occur with this procedure as the frontal sinus osteoplastic flap is made.

Compliance with Ethical Standards

Conflict of interest

the authors have declared that no competing interests exist.

Informed Consent

Informed consent was obtained from all individual participants included in the study