Craniocerebral epidermoid and dermoid tumours: a review of 32 cases

Extradural dermoid tumor of the petrous apex. Case report

Dermoid cysts are rare, benign, congenital tumors. Most case series thus far have featured intradural tumors. The authors report on a case of an extradural dermoid tumor of the middle cranial fossa with osseous invasion, successfully removed using a left subtemporal extradural approach. The clinical presentation, histological features, radiological findings, and management of this unique case are described.

Brainstem epidermoid cyst in a child. Case report

A 10-year-old girl presented with a brainstem epidermoid cyst manifesting as dysphagia and post-prandial vomiting. Magnetic resonance imaging disclosed a cystic mass in the brainstem with associated hydrocephalus. She was treated under a presumptive diagnosis of abscess until the definitive histological diagnosis was established at the fourth admission. In spite of four interventions, she remained in good condition with minimal cranial nerve pareses. Subtotal removal of the epidermoid cyst in the brainstem results in recurrence within a relatively short period, especially in children. Total resection of the tumor is the optimum treatment. The differential diagnosis includes abscess, cystic glioma, and neurenteric cyst.

Intracranial dermoid cyst mimicking hemorrhage. Case report and review of the literature

Intracranial dermoid cysts are rare congenital lesions that result from abnormal sequestration of ectodermal cells during neural tube formation. Dermoid cysts are typically hypodense on computed tomography, but when hyperdense may mimic a hemorrhage. The authors report the case of a 16-year-old boy who presented with a history of chronic progressive headaches. Findings on a CT scan were indicative of hemorrhage. Magnetic resonance imaging revealed the lesion to be a dermoid cyst with unusual characteristics. Upon gross resection, the lesion appeared to be a dermoid cyst without hemorrhage, but histological evaluation revealed evidence of hemorrhage. The authors describe their experience and review the literature, emphasizing that a dermoid cyst may have unusual radiographic characteristics indicative of hemorrhage and may contain areas of hemorrhage on histological examination.

A child with coexistent hemihypotrophy and parapontine epidermoid

This report describes a 10-year-old female who presented with poor growth and right hemihypotrophy. She had crossed sensory findings on neurologic examination consistent with a lateral medullary syndrome with no discernible cranial nerve findings, ataxia, or vertigo. Magnetic resonance imaging of the brainstem revealed a large right parapontine epidermoid. The possible relationship between the hemihypotrophy and the epidermoid is discussed.

Osteosarcoma presenting as a solitary focus of osteolysis in the calvarium

Osteolysis of the skull is fairly common. The clinical presentation and results of laboratory or imaging tests may suggest a benign or a malignant disease. However, histology is the only means of obtaining a definitive diagnosis and should therefore be performed at the slightest doubt. We report the case of a 58-year-old man who presented with a recent painless lump in the right temporoparietal region. Laboratory tests were normal. Brain imaging studies and total body radionuclide scanning showed no other lesions. However, the heterogeneous and aggressive appearance of the skull lesion prompted a surgical biopsy, which showed osteoblastic osteosarcoma. Chemotherapy and radiation therapy were given after complete excision of the tumor.

Sylvian fissure dermoid cyst with intratumoral hemorrhage: case report

It is rare for a dermoid cyst to develop intratumoral hemorrhage. A 61-year-old woman had a sudden-onset left hemiparesis and slow response to verbal requests for one week when unenhanced computed tomography scanning revealed a mixed iso- and hypo-dense heterogeneous lesion in the right fronto-temporal area. T1-weighted magnetic resonance imaging (MRI) of the brain showed a mixed hyper- and hypo-intense tumor in the right fronto-temporal area. The tumor became hyperintense on T2-weighted MRI and was faintly enhanced at tumor periphery on T1-weighted MRI. The tumor was excised and pathological examination revealed a dermoid cyst with intratumoral hemorrhage. The post-operative course was complicated by hemorrhage in the tumor bed, which was evacuated immediately. The patient improved and could walk without support two weeks after the second operation. After 1 year of follow-up, she was well and without neurological deficits. To the best of our knowledge after a literature review, only two previous cases of dermoid cyst have featured intratumoral hemorrhage.

Epidermoid cysts of the cavernous sinus

BACKGROUND

Epidermoid cysts involving the cavernous sinus are rare lesions. They can be divided into 3 different categories: extracavernous, interdural, and true intracavernous.

METHODS

This classification of cavernous epidermoid cysts is correlated with the extent of tumor resection and the clinical outcome in reported cases here and elsewhere.

RESULTS

Patients with cysts invading or compressing the cavernous sinus present with an excellent functional recovery after surgery independent of the extent of tumor resection. In cases of interdural cysts, there is often an adherence of the tumor capsule to the third and fourth cranial nerves. Therefore, in this group, subtotal resection is a safe strategy to prevent surgical morbidity. However, this policy may lead to a higher incidence of tumor recurrence in these cases. In true intracavernous lesions, a higher rate of total removal is possible despite the increased occurrence of internal carotid artery encasement and cranial nerve displacement.

CONCLUSION

Postoperative outcome with preservation of neural and vascular structures in cavernous epidermoid cysts is more likely related to surgical strategy than to tumor localization. Independent of the different tumor origins in these cases, a subtotal resection is usually sufficient to achieve postoperative improvement of the symptoms without additional morbidity.

Dermoid lesion of the cavernous sinus: case report and review of the literature

Intracranial dermoids are rare congenital tumors. Supratentorial dermoid cysts were more frequently reported in the last decade, and they are known to have a predilection for the cavernous sinus. Interdurally localized dermoids presenting with ophthalmoplegia is uncommon. Previously, the association of dermoid lesions with the cavernous sinus and the complexity of the operative procedure were emphasized only by a few authors. We report a case of a dermoid cyst that was embedded fully in the cavernous sinus and review the related cavernous dermoid lesions in the literature. Fronto-orbitozygomatic craniotomy was performed, and despite adherence of the tough capsule to the cranial nerves, the lesion was grossly removed in total. The patient was doing well 1 year after the operation, and there was no recurrence of signs and symptoms. Interdural growth of cavernous dermoid tumors must be considered, and careful evaluation of preoperative computed tomography and magnetic resonance images aids in making the decision concerning the operative approach. Upon review of the literature, we detected only eight similar cases concerning cavernous dermoid cysts. Although total excision of these cavernous lesions has been reported previously, we believe that total excision can sometimes be hazardous and not feasible.

Maxillary bone epithelial cyst in a dog

A swelling ventromedial to the left eye of a one-year-old, neutered male Labrador failed to respond to antibiotic and anti-inflammatory therapy. Plain and contrast radiography revealed a spherical, radiolucent area, 1.5 cm in diameter, dorsomedial to the fourth maxillary premolar and rostral to the ethmoid region. The lesion was thin-walled, with a smooth radiopaque margin, and was clearly demarcated from the surrounding structures. Dacryocystography demonstrated no apparent physical association between the lesion and the nasolacrimal duct, the latter appearing normal. Ultrasonography of the lesion showed a round, anechoic structure consistent with the appearance of a cyst. Prior to surgical excision of the lesion, intralesional fluid was aspirated. Bacteriology of the fluid was negative for both aerobic and anaerobic organisms. Cytological examination of the fluid showed a few macrophages and small lymphocytes; neither significant inflammatory component nor neoplastic cells were found. Histology showed the lesion to be a benign epithelial cyst. The dog recovered uneventfully and there was no clinical evidence of recurrence within a two-year follow-up period.

Cerebellopontine angle epidermoids presenting with cranial nerve hyperactive dysfunction: pathogenesis and long-term surgical results in 30 patients

OBJECTIVE

To provide the characteristics and long-term surgical results of patients who present with cerebellopontine angle epidermoids and trigeminal neuralgia (TN) or hemifacial spasm.

METHODS

A total of 30 patients (23 women, 7 men) who presented with cerebellopontine angle epidermoids and TN (28 patients) or hemifacial spasm (2 patients) between 1982 and 1995 were reviewed, with emphasis being placed on the clinical manifestations, the mechanisms of symptom development, the long-term follow-up results, and the anatomic relationship between the tumor and the surrounding neurovascular structures.

RESULTS

The average age of the patients was 37.8 years at symptom onset and 49.3 years at the time of the operation. The tumor-nerve relationships were classified into four types: complete encasement of the nerve by the tumor, compression and distortion of the nerve by the tumor, compression of the nerve by an artery located on the opposite side of the unilateral tumor, and compression of the nerve by an artery on the same side of the tumor. Total resection was achieved in 17 patients (56.7%). Microvascular decompression of the respective cranial nerve was achieved in nine cases of direct arterial compression in addition to tumor removal. The symptom was relieved completely in all cases. In an average follow-up period of 11.5 years, three patients developed recurrent symptoms: two experienced tumor regrowth, and one had arachnoid adhesion.

CONCLUSION

Hyperactive dysfunction of the cranial nerves, especially TN, may be the initial and only symptom that patients with cerebellopontine angle epidermoids experience. The occurrence of TN at a younger age was characteristic of TN patients with epidermoids, in contrast to patients with TN due to a vascular cause. The symptom is elicited by compression of the nerve by the tumor per se, by an artery that is displaced to the nerve, or by both. Careful resection of the tumor, whose capsule occasionally is strongly adherent to the neurovascular structures, is necessary, and microvascular decompression to straighten the neuraxis should be performed in some cases to achieve a complete, permanent cure of symptoms with a low rate of recurrence.

Mobile intracranial oily substances from a ruptured teratoma

A patient with a ruptured intracranial teratoma is presented. The distinctive imaging and neuroendoscopic findings of mobile fatty or oily globules in the subarachnoid or ventricular space are described. Fat suppression magnetic resonance imaging (MRI) and MRI performed with the patient prone was helpful in distinguishing tumour tissue from floating oil.

Malignant transformation of cerebello-pontine angle epidermoid

A 55-year-old woman presented with fever and a stiff neck due to an intracranial poorly differentiated carcinoma at the right cerebellopontine angle. The patient suffered from typical trigeminal pain and had undergone a removal of the right cerebellopontine angle epidermoid 13 years before at another hospital. On admission, MRI imaging showed a lesion at the right cerebellopontine angle with marked contrast enhancement. Partial removal of the tumor was achieved. A histological examination of the tumor showed a poorly differentiated carcinoma accompanied by typical desquamated tissue of the epidermoid. The patient died 3 months after the operation because of aggressive meningeal carcinomatosis.

Intracerebral epidermoid tumor: a case report and review of the literature

BACKGROUND

Intracerebral epidermoid cysts are rare lesions and may account for only 1.5% of intracranial epidermoid tumors. Cell entrapment from the mesectodermal origin of the neural crest within the primitive cerebral hemisphere may lead to the formation of such rare intracerebral lesions.

METHODS

An intracerebral epidermoid cyst located in the right temporal lobe that was surgically treated is presented. The origin, clinical course, radiological features, and surgical treatment of such uncommon lesions are discussed based on a review of the literature.

RESULTS

Intraoperative findings revealed an epidermoid tumor. The postoperative course was uneventful and the patient was discharged with no neurological deficits. On long-term follow-up (2 years), there were no signs of recurrence.

CONCLUSIONS

Truly intracerebral epidermoid tumors are rarely found. Cells originating from mesectodermal lines may migrate and remain trapped within the primitive cerebral hemisphere while the neural tube is closing, leading to the formation of such intraparenchymal epidermoid tumors. Accurate preoperative diagnosis can be very difficult due to the radiological similarities to other common intracerebral cysts (e.g., astrocytomas or gliomas). Magnetic resonance imaging (MRI) studies, especially with diffusion-weighted images, allow greater accuracy in the preoperative differential diagnosis. Radical surgical removal should be attempted, but a less aggressive surgical strategy should be considered if there is strong adherence between the tumor capsule and the brain tissue, particularly in eloquent areas.

Subarachnoid fat dissemination after resection of a cerebellopontine angle dysontogenic cyst: case report and review of the literature

OBJECTIVE AND IMPORTANCE

This case report illustrates the clinical and radiological relevance of extensive intracranial subarachnoid and ventricular dissemination in dysontogenic (dermoid) tumors.

CLINICAL PRESENTATION

We describe a patient with a cerebellopontine angle dysontogenic tumor. Postoperatively, the cyst disseminated fat particles extensively into the subarachnoid space. Magnetic resonance imaging (MRI) studies revealed continuous dispersion of the fat particles into the cerebral cisterns, subarachnoid space, and ventricles.

INTERVENTION

Eight years of clinical and MRI follow-up demonstrated neither neurological deterioration in the patient nor growth of the multiple lesions.

CONCLUSION

Intracranial subarachnoid dissemination of fat material may occur during the preoperative or postoperative course of dermoid and epidermoid cysts. Aseptic meningitis or other complications such as hydrocephalus, seizures, or cranial nerve deficits also may occur owing to spillage of intracranial cyst contents into the subarachnoid space. MRI can detect the presence of fat drops that may adhere to the surrounding structures or migrate with the cerebrospinal fluid flow. Intracranial disseminated fat particles can remain silent without radiological or neurological change, justifying a wait-and-see approach. During long-term postoperative follow-up, however, regular MRI studies and clinical examinations are necessary to avoid potential complications.

Temporal dermoid cyst with a partial dermal sinus tract

BACKGROUND

Cranial dermal sinuses are rare and occur most frequently in the posterior fossa and along the midline. Likewise, supratentorial dermoid cysts are very uncommon.

METHOD

We report a unique case of an adult female patient with both a supratentorial dermoid cyst and an incomplete dermal sinus tract.

RESULTS

The patient is a 31-year-old female, who presented with a new onset complex partial seizure. Neuroimaging and surgery revealed a right superior temporal dermoid cyst with an associated dermal sinus tract. Furthermore, the dermal sinus tract was incomplete and had no cutaneous manifestations.

CONCLUSION

We present a rare patient with an off midline supratentorial dermoid cyst associated with a uniquely incomplete cranial dermal sinus tract. The dermal sinus tract involved the bone, dura and intradural compartment, without involving the overlying skin. This represents a novel variant in the spectrum of cranial dermal sinus abnormalities.

Magnetic resonance imaging of a medullary dermoid cyst with secondary hydrocephalus in a dog

Magnetic resonance images were acquired of the brain of a 7-year-old male Golden Retriever with hydrocephalus secondary to a medullary lesion. Images were acquired prior to and 4 weeks following surgical treatment for the hydrocephalus, and the dog was euthanased following the second imaging session. The MR images demonstrated a medullary lesion with patchy but predominantly hyperintense signal with both T1- and T2-weighting, within which small areas of low signal were scattered. There was little edema associated with this lesion and no enhancement with gadolinium. Postmortem examination revealed the medullary mass to be a dermoid cyst. Several small nodular lesions were identified within the central nervous system on the magnetic resonance images whose origin was uncertain on postmortem examination.

Assessment and surgical management of posterior fossa epidermoid tumors: report of 28 cases

OBJECTIVE

The management of a series of 28 patients operated on for posterior fossa epidermoids is reviewed, emphasizing the need for long-term follow-up. We discuss the rationale for a comprehensive classification system that may allow the comparison of results from homogeneous series.

METHODS

We grouped the tumors to differentiate the surgical management according to various tumor sites and the degree of extension. Twenty patients harbored tumors located in the cerebellopontine angle, five patients harbored tumors in the fourth ventricle, and three patients harbored tumors in the posterior fossa basal. In 17 patients, extensions of tumors outside the posterior fossa included the following regions: the suprasellar/ chiasmatic (n = 5), the parasellar/temporobasal (n = 5), and the mesencephalic/pineal (n = 7). Tumor extension was also defined by the number of regions involved. Pre- and postoperative magnetic resonance imaging and computed tomographic findings collected in 17 and 28 patients, respectively, were carefully evaluated.

RESULTS

Clinical features and surgical approaches varied according to location and growth pattern. Fifty-seven percent of the tumors were completely removed. A higher total removal rate was achieved in patients with tumors confined to the primary location. One patient (3%) died in the perioperative period. Approximately half of the patients presented with transient mild focal deficit impairments resulting from the manipulation of the nervous structure over a wide area. There was a higher rate of surgical complications with fourth ventricle and mesencephalic extended cerebellopontine angle tumors. The mean follow-up period was 8.6 years. Thirty percent of the patients with subtotal removal experienced symptomatic recurrences after 8.1 years, whereas all patients with total removal were still asymptomatic. The recurrence-free survival rate was 95% at 13 years for patients with total removal compared with 65% for patients with subtotal removal. Problems of identification of tumor regrowth are discussed.

CONCLUSION

By assessing posterior fossa epidermoids, we determined that location and extension play a major role in the prognosis. Our data suggest that more aggressive surgery is called for at first operation, and that a second operation should be planned when regrowth becomes symptomatic and/or tends to extend outside its original site.