A nasal sinus mucocele is a benign cystic tumor that develops at the expense of the sinus mucous membranes and is due to a lack of ventilation of the sinus concerned [1]. Frequent localizations are frontal or fronto-ethmoid in 60% of cases [2]. Despite its histological benignity, this tumor has an aggressive potential in the orbit and brain that can lead to formidable complications [3],[4]. This lytic potential of the bone walls of the sinuses can sometimes pose diagnostic and management problems, thus requiring multidisciplinary expertise [5],[6]. The ENT and Ophthalmology Departments of Saint Joseph Hospital in Kinshasa, in collaboration with the team from the University of Rostock (ophthalmologist specialized in orbital diseases and neuroradiologist), took care of a case of giant fronto-ethmoido-orbital mucocele during the period from 22/11/2023 to 09/04/2024.

Objectives

The main objectives of this article were, on the one hand, to describe the clinical, radiological, and therapeutic characteristics of this condition and, on the other hand, to determine the place of telemedicine and multidisciplinary management in the event of complications of this condition in environments in resource-limited countries.

A 38-year-old female patient, with no particular sinus history, referred to the Ophthalmology Department for better management of chronic sinusopathy complicated by documented mucocele. The early symptoms were marked (four years earlier) by redness and ocular globe protuberance of the right eye which were neglected. Two years later, during a pregnancy, the swelling worsened; this prompted the patient to consult an Ophthalmology Department.

The ENT examination on admission revealed exophthalmos with preservation of extrinsic oculomotor function. The rest of the ENT examination was unremarkable.

The ophthalmological examination already showed a visual impairment of 6/24 in the right eye and 6/9 in the left eye, a sensitivity to the pressure of the superior orbital rim in the supranasal of the right eye, axile exophthalmos with limitation of adduction and superduction, an intraocular pressure of 17.3 mmHg in the right eye and 14.6 mmHg in the left eye and diplopia (Figure 1).

The computed tomography (CT) scan of the sinus performed on 24/07/2023 concluded that there was chronic sinusopathy complicated by mucocele of the right frontal sinus and osteolysis with grade II exophthalmos (Figure 2A).

The sinus CT scan with contrast agent injection performed on 05/02/2024 suggested the presence of an extraconical tissue process of the right orbit responsible for grade 3 exophthalmos, the implantation base of which is located at the level of the inner wall. This mass was responsible for bone lysis extending to the level of the anterior and posterior ethmoid cells. It also extended to the right frontal sinus with lysis of the anterior wall (Figure 2B).

In view of this evolution of the lytic lesions on CT scans, the opinions of the ophthalmologist specialized in orbital diseases and the neuroradiologist was required by telemedicine. The specialists from the University of Rostock (Germany) consulted and confirmed the diagnosis of a right fronto-ethmoid mucocele in the first hypothesis, in view of the patient’s age and the bone which seemed to be enlarged rather than destroyed. Surgical drainage of sinus was advised.

The fronto-eyebrow approach of Jacques was then performed and showed a lysis of the anterior wall of the right frontal sinus causing a yellowish, sticky liquid to emerge, which had not been cultured. This fluid extended into the ethmoid cells with lysis of the orbital wall and the posterior wall of the sinus. A large fronto-ethmoidectomy allowed the complete excision of the cyst, the closure of the posterior wall of the right frontal sinus with bone wax, the repermeabilization and drainage of the nasofrontal canal thanks to a sloping drain left in place for two months

The postoperative effects were simple and the follow-up after six months was unremarkable. The ENT and ophthalmological examinations noted a very good evolution (visual acuity of 6/6, significant reduction in exophthalmos, absence of orbital rim pain, and disappearance of diplopia) both from a clinical and aesthetic point of view (Figure 3 and Figure 4).

The objectives pursued by this article were first to describe the clinical, radiological, and therapeutic characteristics of this condition; secondly, to determine the place of telemedicine and multidisciplinary management in the event of complications of this condition in an environment with limited resources. From a clinical point of view, in our clinical case, the symptoms were dominated exophthalmos and diplopia, which led the patient to logically consult the ophthalmology department after four years of evolution without treatment. Indeed, it is described that the symptomatology of a fronto-ethmoid mucocele can remain silent for a long time, the initial signs are essentially dominated by frontal or orbital swelling, ocular signs as exophthalmos, diplopia, deviation of the eyeball with limitation of eye movements and in the late stage a decrease in visual acuity [7],[8].

From the point of view of diagnosis, the craniofacial CT scan is the examination of choice in case of clinical or endoscopic suspicion of mucocele and allows, apart from the diagnosis, to make an assessment of the bone lesions as described in the case under study. In case of diagnostic doubt, intraorbital or intracranial extension, magnetic resonance imaging (MRI) allows a better analysis of the lesions [3],[8],[9]. The latter was not carried out by the patient due to lack of financial means and we referred to the various expert advice for the choice of treatment. Indeed, the treatment of mucoceles is surgical: either externally (eyebrow or gingivo-jugal depending on the location) or endoscopic [4].

In the present clinical case, we opted for the external eyebrow route because of the diagnostic doubt, the description of bone lysis suggestive of an orbitoencephalic extension and anterior fistulization toward the soft tissues as well as the possibility of performing a large fronto-ethmoidectomy for a good drainage of the mucocele. The good clinical outcome after a 6-month follow-up justifies this choice and confirms the diagnosis of mucocele although bacteriological examinations of the secretions have not been carried out [10]. However, medium- and long-term monitoring is necessary to judge the success of the intervention (6–12 months) [11].

In addition, the management of our patient raises two problems: the first is related to the long evolution of the pathology before the actual treatment, and the second, raising the problem of managing the complications of this condition in environments with limited resources. This long standing of the pathology before the current treatment is the result of negligence and the lack of adequate resources in our environments, as demonstrated by the case in study.

In the series of Bouatay et al., the duration of evolution of the pathology was from 1 to 84 months, in particular because of the complex symptomatology: ophthalmological, neurological, rhinological, or aesthetic, demonstrating the major role of imaging in the diagnosis and management of mucoceles. Hence the interest of multidisciplinary care in the management of this condition [3].

This multidisciplinary management is becoming imperative, especially in the management of complications. Expansion toward the orbit and toward the brain represents the most severe complications of fronto-ethmoid mucoceles and requires the expertise of an ophthalmologist specialized in orbital diseases, a neurosurgeon or a neuroradiologist outside the ENT and the ophthalmologist. In environments where this expertise may be lacking, the use of a tele-expertise can give better quality of specialized care.

Fronto-ethmoidal mucocele is a rare condition in our environment. Its symptomatology is often silent for a long period of time, and this evolution can lead to bone lysis, which may extend to the orbit or brain. Craniofacial CT scan is the procedure of choice for diagnosis and magnetic resonance imaging provides a better analysis in cases of doubt. In resource-limited environments, multidisciplinary management including ophthalmologists, radiologists, neurologists, or even tele-expertise can lead to a judicious therapeutic choice.