Magnetic resonance imaging of a giant frontal hemorrhagic mucocele with intracranial extension in a cat

A 6-year-old domestic short-haired cat was presented with an acute onset of right cortical encephalopathy. Magnetic resonance imaging (MRI) performed 4 days after the onset of clinical signs revealed a lesion originating from the right frontal sinus with intracranial extension and compression of the right frontal lobe. The lesion was T1-weighted hypointense and T2-weighted and fluid-attenuated inversion recovery hyperintense. Signal voids within the lesion were observed on T2* images, consistent with hemorrhage. Peripheral ring enhancement was visible on postcontrast sequences. These features were consistent with a giant hemorrhagic mucocele. To the authors' knowledge, this is the first report of MRI characteristics of this lesion in a cat.

Frontoethmoidal Mucoceles: CT and MRI Evaluation

Paranasal sinus mucocele is an expanded, airless, mucus-filled sinus caused by obstruction of the sinus ostium. It is a benign slow growing epithelial lined lesion, bulging against adjacent anatomical structures, without infiltrating them. The purpose of our study is to describe the CT and MR findings in 19 patients (ten women, nine men, 18–72 years, mean age: 48.1) with surgically confirmed frontoethmoidal mucoceles between 1999–2005. CT scans displayed mucoceles as non enhancing soft tissue density lesions, generally isodense to the brain parenchyma, expanding the sinuses in most cases, eroding adjacent bones and extending intraorbitally or intracranially. Signal intensity in T2WI and T1WI MR images varied, but generally lesions had high signal intensity in T2WI and low to intermediate signal intensity in T1WI. Some of the lesions demonstrated regular linear peripheral enhancement after administration of contrast medium. The causes of mucoceles included mucosal thickening from chronic sinusitis, adhesions from previous operation in the nasal cavity, previous trauma, small nasal polyps and a small osteoma, while in six patients (31.5%) the cause of the mucocele remained unrecognized even after surgery. No underlying malignant tumor was found in any of the cases as the cause of obstruction. CT and MRI established the correct diagnosis in all patients. CT was more sensitive in determining bone erosions, while MRI had the advantage of multiplanar imaging and was much more sensitive for differentiating mucocele from a tumor on the basis of MR signal intensity characteristics. In conclusion, CT and MRI are the methods of choice for diagnosing mucoceles of the paranasal sinuses and are of major importance for the treatment plan. Each method seems to have its own advantages and should be used as complementary investigations of sinonasal pathology. Enhanced CT scan should only be performed in the absence or contraindication for enhanced MR imaging.

Extensive paranasal sinus mucoceles: a 15-year review of 82 cases

PURPOSE

The aim of the study was to report the clinical characteristics, management, and outcome of patients with extensive paranasal sinus mucoceles.

MATERIALS AND METHODS

In a retrospective study, 82 patients with intracranial or intraorbital extension due to paranasal sinus mucoceles who were surgically treated between 1993 and 2007 were studied. In addition, clinical data, presenting symptoms, clinical features, management, and outcome were analyzed.

RESULTS

The study population included 42 males and 40 females, with a mean age of 52.7 years (range, 15-87 years). The most common presenting symptoms were ptosis (27/82, 32.9%) and periorbital swelling (24/82, 29.3%). The main radiologic finding on computed tomography scan was bony defect of lamina papyracea and/or medial superior orbital rim. Sixty-six patients underwent endoscopic sinus surgery; among them, 3 patients had recurrence (3/77, 3.9%) during follow-up periods.

CONCLUSION

In our study, a majority of patients with extensive paranasal sinus mucoceles exhibited ophthalmologic symptoms before treatment (81/82, 98.8%). Computed tomography scanning was a feasible tool for preoperative assessment. A satisfactory outcome can be achieved after surgical treatment of endoscopic sinus surgery.

Giant mucocele of the frontal sinus

Giant mucocele of the frontal sinus is a rare pathology of benign entity caused by retention of mucous secretions in the sinus. It may expand and erode the surrounding structures such as bones and cerebral parenchyma. The authors describe a patient with frontal giant mucocele involving the orbit, the ethmoid, and intracranial portion of the dura. The main presenting symptoms were diplopia and proptosis. A computed tomography scan and magnetic resonance imaging were performed to permit differential diagnosis from other pathologies such as ossifying fibroma, fibrous dysplasia, and other neoplasms. A single stage maxillofacial and neurosurgical approach to treatment was taken consisting in the removal of the mucocele and reconstruction of the eroded bones with cranial bone grafts. The dura was repaired with temporalis muscle fascia sealed with fibrin glue. Two years after surgery, the patient shows no recurrence and satisfactory morphologic and functional results.

Symptomatic epilepsy due to a huge frontal sinus mucocele. A case report

We report the case of a 57-year-old man complaining of headaches and adult onset seizures. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed a process which proved to be a huge frontal sinus mucocele, eroding the posterior wall of the frontal sinus and compressing the left frontal lobe. An osteoplastic flap procedure with cranialization and obliteration of the frontal sinus was performed. The seizures and headache disappeared postoperatively. Clinical manifestations, diagnosis and surgical approaches for grand frontal sinus mucoceles are briefly discussed.

Giant Frontoethmoid Mucocele with Intracranial Extension: Case Report

We report the case of a 31-year-old woman who came to us with a giant frontoethmoid mass that had extended into the intracranial region and invaded the left orbit. We removed the lesion in its entirety via a combined intranasal and transcranial approach. We discuss the advantages and disadvantages of different surgical approaches, and we explain why we recommend a combined approach for the type of giant lesion that we encountered.

Imaging of frontal sinus disease: concepts, interpretation, and technology

Imaging of the frontal sinus is an integral part of patient evaluation. High-resolution computed tomography (CT) imaging is the preferred modality for evaluation of sinus inflammatory disease. Magnetic resonance (MR) imaging plays an important role in differentiating tumors from inflammatory diseases and serves as a problem-solving tool.

Intracranial spread of a giant frontal mucocele: case report

A giant mucocele eroded both the anterior and posterior wall of the frontal sinus and infiltrated the dura mater. Its extracranial growth caused a frontal bony prominence. The tumour and part of the dura were resected. A 12 x 6cm defect in the dura was repaired with a freeze-dried patch. A split-thickness bone graft from the right parietal region was used to repair the anterior frontal bony defect. The result one year later was satisfactory. Spiral computed tomography with thr ee-dimensional reconstructions excluded any recurrence of the tumour and showed good integration of bone grafts.

Intracranial mucocele as a complication of endoscopic repair of cerebrospinal fluid rhinorrhea: case report

OBJECTIVE AND IMPORTANCE

Endoscopic repair of an anterior cranial fossa cerebrospinal fluid (CSF) fistula has gained widespread acceptance. We report a case of mucocele development at the site of an endoscopic CSF leak repair.

CLINICAL PRESENTATION

A 46-year-old woman underwent functional endoscopic sinus surgery for nasal obstructive symptoms. The surgery was complicated by an intraoperative CSF leak from the posterior cribriform plate/anterior sphenoid, which was repaired immediately using bone and mucosa grafts. Two years postoperatively, a 13-mm anterior cranial base mass was found incidentally. This mass increased to 20 mm over the next year.

INTERVENTION

The anterior cranial base mass was excised via a right frontal craniotomy and confirmed histologically to be a mucocele.

CONCLUSION

Endoscopic repair of an anterior cranial base CSF fistula with mucosal grafts may lead to formation of a mucocele.