Malignant transformation of posterior fossa epidermoid cyst

Epidermoid cyst of the cerebellar vermis: Case report of a rare medial topography

Intracranial epidermoid cysts are very rare benign tumors representing less than 2% of intracranial tumors. They are located preferentially in the cerebellopontine angles, parasellar, and temporal regions. We report here the case of an epidermoid cyst of very uncommon medial location in the cerebellar vermis, in a 61-year-old female patient complicated with tumor protrusion into the foramen magnum and active hydrocephalus.

Concurrent occurrence of squamous cell carcinoma in a cerebellopontine angle epidermoid cyst: A case report and review of the literature

Background:

Intracranial epidermoid cysts are rare benign lesions. Cases of malignant transformation (MT) into squamous cell carcinoma (SCC) have rarely been reported. We present a case of concurrent occurrence of SCC diagnosed during primary resection of epidermoid cyst (EC) and a relevant literature review.

Case Description:

A 61-year-old patient was diagnosed with a right cerebellopontine angle (CPA) lesion after suffering from vertigo, diplopia, and right trigeminal (V2) hypoesthesia. Brain magnetic resonance imaging (MRI) showed a lesion consistent with an EC, demonstrating restricted diffusion with rim-enhancing area on the medial side of the cyst. During resection, two different tissue pathologies were observed, one consistent with an epidermoid (which was completely removed) and an additional firm tissue adherent to the brainstem, preventing gross total resection. Pathological evaluation confirmed two separate histologies – epidermoid and SCC. The patient never recurred to complete the recommended radiotherapy. Eleven months following surgical resection, a follow-up MRI showed local massive recurrence of the enhancing lesion. He was, further, treated with radiotherapy and is currently being followed up.

Conclusion:

MT of an intracranial EC to SCC is rare and associated with poor prognosis. SCC may be found incidentally at time of primary resection or arise from a remnant of previously operated EC. Thus, aggressive complete resection should be intended, and separate pathological specimens should be sent from any abnormal region of the tumor.

A Case of Telangiectatic Osteosarcoma in the Frontal Bone

Telangiectatic osteosarcoma (TOS) is a subtype of osteosarcoma. TOS in the elderly and TOS in the skull are very rare. Here, we report a case of TOS in the frontal bone of an elderly patient. The patient was a 79-year-old woman who was identified as having a right frontal bone lesion. The patient was initially diagnosed with an intradiploic epidermoid cyst (IEC). A 60mm cystic lesion with bone destruction appeared 5 years later, which enlarged over 2 months. The fluid in the cyst seemed to be blood that had lost its clotting ability. Tumor and the surrounding tissue were resected. The postoperative course was favorable. Postoperative magnetic resonance imaging (MRI) showed no evidence of residual lesions. There was no metastases. Histopathologically, the cyst wall was composed of fibrous connective tissue and did not contain epithelial components. There were no skin appendages and keratinized tissues in the lesion. Based on these findings, the diagnosis changed to aneurysmal bone cyst (ABC). Subsequent immunohistochemical examinations confirmed that the MIB-1 index was 50% in some sections and there were atypical cells showing osteogenic properties in other sections. Based on these results, the patient was finally diagnosed with TOS. The differential diagnoses for cystic lesion presenting bone destruction include TOS, ABC, and IEC. In case of cystic lesion with bone destruction, early diagnosis based on histopathological study is important and complete resection with surrounding tissues is required, given the possibility of TOS.

Primary Squamous Cell Carcinomas Arising in Intracranial Epidermoid Cysts: A Series of Nine Cases and Systematic Review

Objective

Primary squamous cell carcinomas (PSCCs) arising in intracranial epidermoid cysts (IECs) are very rare, and their management and prognostic factors remain unclear. This study aimed to enunciate the clinical features and suggest a treatment protocol based on cases from the literature and the cases from our institution.

Methods

The clinicoradiological data were obtained from nine patients with PSCCs arising in IECs, who underwent surgical treatment at Beijing Tiantan Hospital between July 2012 and June 2018. We also searched the PubMed database using the keywords “epidermoid cyst(s)” or “epidermoid tumor(s)” combined with “malignant” or “malignancy” or “intracranial” or “brain” or “squamous cell carcinoma” between 1960 and 2020. Risk factors for overall survival (OS) were evaluated in the pooled cohort.

Results

The mean age of our cohort was 51.2 ± 8.3 years (range: 39–61 years), which included eight males and one female. Gross total resection (GTR) was achieved in three patients, while non-GTR was achieved in six patients. Radiotherapy was administered to five patients. After a median follow-up of 16.7 ± 21.6 months (range: 3–72 months), eight patients died with a mean OS time of 9.75 ± 6.6 months (range: 3–23 months). In the literature between 1965 and 2020, 45 cases of PSCCs arising in IECs were identified in 23 males and 22 females with a mean age of 55.2 ± 12.4 years. GTR, non-GTR, and biopsy were achieved in six (13.3%), 36 (80%), and three (6.7%) cases, respectively. After a mean follow-up of 12.7 ± 13.4 months (range: 0.33–60 months), 54.1% (20/37) patients died, and recurrence occurred in 53.6% (15/28) patients. A multivariate analysis demonstrated that postoperative radiotherapy (p = 0.002) was the only factor that favored OS. The Kaplan–Meier analysis showed that, compared with no radiotherapy (median survival time: 4 months), radiotherapy (median survival time: 24 months) had significantly prolonged OS (p = 0.0011), and GTR could not improve OS (p = 0.5826), compared with non-GTR. The 1-year OS of patients with or without radiotherapy was 72.5% or 18.2%, respectively.

Conclusion

Malignant transformation of IEC into PSCC was prevalent in elderly patients, with slight male predominance. GTR of previous benign IECs is recommended. For remnant benign IECs, close follow-up should be performed. Postoperative radiotherapy for PSCCs could bring survival benefit. GTR of these malignant intracranial tumors is difficult when they involve important brain structures. Future studies with larger cohorts are necessary to verify our findings.

Giant Epidermoid Cyst of Posterior Fossa-Our Experience and Literature Review

Introduction. Intracranial epidermoid cysts are the most frequent congenital intracranial lesion. They rare and benign tumors that can present in different clinical situations depending on location and extension of the disease. Diagnosis is obtained with radiological imaging with RM and non-enhanced TC as elective investigating methods. Elective treatment is surgery, based on total/subtotal excision sparring healthy neurovascular structures, considering the benign nature of this lesion. Case Report. In this study we present the case of a 79-year-old woman affected by recidivist epidermal cyst of the posterior fossa. Clinical presentation was characterized by positional subjective vertigo, intense headache localized in the right part of the head increased by Valsalva maneuver and retroarticular subcutaneous swelling. Radiological investigation found a giant epidemoid cyst of the posterior fossa (8,4 x 4,8 x 5,8 cm), treated with surgery. In the postoperative, the patient was fine and no neurological deficit has been encounterd. REVIEW. In this study, we present a review of the literature regarding giant epidermoid cysts of posterior fossa. Only 11 cases were reported before ours, which actually is one of the largest ever described.

Primary Intracranial Malignant Epidermoid with Multiple Metastases in Internal Organs: A Rare Autopsy Case

Primary intracranial malignant epidermoids are rare, with most cases developing from a pre-existing benign epidermoid cyst. We report a case involving a rare autopsy finding of a primary intracranial malignant epidermoid in the brainstem with cerebellopontine angle (CPA) involvement. A 53-year-old woman with double vision was diagnosed with right abducens palsy. At her visit to our hospital 3 months after the onset of the first symptom, she presented left hypoglossal nerve paralysis and truncal ataxia in addition to right abducens palsy. Magnetic resonance imaging (MRI) revealed a mass lesion (2-cm long and 3-cm thick) in the left CPA that exhibited gadolinium enhancement. Moreover, gadolinium-enhanced magnetic resonance imaging (MRI) revealed abnormal multiple brainstem and supratentorial mass lesions with partial enhancement. Whole-body computed tomography failed to identify any possible primary lesion. Following a tentative diagnosis of an epidermoid cyst with an assumption that the tumor was highly aggressive, we performed subtotal surgical resection of the CPA tumor. Histological findings revealed a malignant epidermoid in the CPA lesion. Although the patient underwent radiation and chemotherapy after the surgical resection, she died of respiratory failure 10 months after the onset of symptoms. Herein, we report the rare clinical course and autopsy data, and discuss the characteristic features of this rare condition.

Cerebellar Vermian Epidermoid Tumor: A Report of 2 Cases

BACKGROUND

Epidermoid tumors are rare, benign slow-growing congenital tumors, most frequently located in the cerebellopontine angle of the intracranial cavity. They usually grow to a large size before patients become symptomatic. Although these tumors are amenable to surgery, their adherence to neurovascular structures poses a surgical challenge that results in subtotal resection, thus increasing the risk of recurrence.

CASE DESCRIPTION

We report 2 adult patients whose imaging studies revealed epidermoid tumors located in the cerebellar vermis, an uncommon site for such tumors. The patients presented with variable symptomatology. We highlight the imaging features and challenges of surgery. Both patients had good outcomes, with resolution of symptoms and neurologic deficits.

CONCLUSIONS

A safe complete excision of epidermoid tumor and its capsule is possible with a good understanding of their clinical and radiologic features and a high index of suspicion. To the best of our knowledge, this is the first report of cerebellar vermian epidermoid tumors from sub-Saharan Africa.

Intracranial squamous cell carcinoma arising in a cerebellopontine angle epidermoid cyst: A case report and literature review

RATIONALE

Most of the intracranial epidermoid cysts are benign, but malignant lesions are occasionally reported. These lesions appear as squamous cell carcinoma and carry a dismal prognosis. Here, we report a case of a primary intracranial squamous cell carcinoma arising in a cerebellopontine epidermoid cyst. The relevant literatures were also reviewed.

PATIENT CONCERNS

A 53-year-old woman presented with dizziness and diplopia 9 months in duration. Magnetic resonance imaging revealed an epidermoid cyst in the left cerebellopontine angle and prepontine region with a focal enhancing lesion on T1-weighted gadolinium-enhanced images.

DIAGNOSES

Histopathologic diagnosis revealed squamous cell carcinoma on a background of epidermoid cyst. Imaging studies excluded metastases.

INTERVENTIONS

The tumor was removed subtotally through a lateral suboccipital approach. The patient received intensity modulated radiation therapy (6720 cGy total) postoperatively.

OUTCOMES

The patient was free from recurrence of the tumor until 3 years after surgery, at which point she was lost to follow-up. The patient died 4 years after the surgery.

LESSONS

The epidermoid cyst may occasionally become malignant. Finding an area of enhancement through preoperative magnetic resonance imaging can help to make a correct diagnosis. Based on the review of previous reports, surgical removal followed by radiotherapy shows the best result to treat malignant epidermoid cysts.

Triple pathological findings in a surgically amenable patient with mesial temporal lobe epilepsy

Mesial temporal sclerosis (MTS) is a well-recognized cause of intractable epilepsy; however, coexistence with focal cortical dysplasia (FCD) is less common. Middle fossa epidermoid cysts are rare and may involve the temporal lobe. Most epidermoids are clinically silent, slow-growing, and seldom associated with overt symptomatology, including seizures. We describe a patient with multiple comorbidities including left MTS and a large epidermoid cyst involving the left quadrigeminal plate cistern compressing upon the cerebellar vermis and tail of the left hippocampus, resulting in refractory left temporal lobe epilepsy. The patient underwent left anterior temporal lobectomy. The surgical pathology demonstrated a third pathological finding of left temporal FCD type Ia. The patient has been seizure-free since the surgery. This case provides additional information with regard to the understanding of epileptogenicity and surgical planning in patients with MTS and epidermoid cysts.

Intracranial epidermoid tumor; microneurosurgical management: An experience of 23 cases

OBJECTIVES

An intracranial epidermoid tumor is relatively a rare tumor, accounting for approximately 0.1% of all intracranial space occupying lesions. These are also known as pearly tumor due to their pearl like appearance. In this series, the localization of the tumor, presenting age and symptoms, imaging criteria for diagnosis, surgical management strategy with completeness of excision and overall outcome were studied prospectively. Here, we report our short experience of intracranial epidermoid as a whole.

MATERIALS AND METHODS

Between January 2006 to December 2010, 23 cases of intracranial epidermoid were diagnosed preoperatively with almost certainty by computed tomography (CT) and magnetic resonance imaging (MRI) of brain in plain, contrast and other relevant studies. All of them underwent operation in Dhaka Medical College Hospital and in some Private Hospital in Dhaka, Bangladesh. All patients were followed-up routinely by clinical examination and neuroimaging. Average follow-up was 39 (range-71-11months) months. Patients of the series were prospectively studied.

RESULTS

Supratentorial epidermoids were 04 cases and infratemporal epidermoids were 19 cases. Clinical features and surgical strategy varies according to the location and extension of the tumors. Age range was 19-71 years (37.46 years). Common clinical features were headache, cerebellar features, seizure, vertigo, hearing impairment and features of raised intracranial pressure (ICP). Investigation was CT scan or/+ MRI of brain in all cases. Pre-operative complete excision was 20 cases, but post-operative images showed complete excision in 17 cases. Content of tumor was pearly white/white material in all cases except one, where content was putty material. Re-operation for residual/recurrent tumor was nil. Complications included pre-operative mortality one case, persisted sixth nerve palsy in one case, transient memory disturbance one case, and extra dural hematoma one case. One senior patient expired three months after the operation from spontaneous intracerebral hemorrhage. Rest of the patients were stable and symptom/s free till last follow-up.

CONCLUSION

In the management of such tumors, one should keep in mind that an aggressive radical surgery carrying a high morbidity and mortality and a conservative subtotal tumor excision is associated with a higher rate of recurrence, but earlier diagnosis and complete excision or near total excision of this benign tumor can cure the patient with the expectation of normal life.

An analysis of intracranial epidermoid tumors with malignant transformation: treatment and outcomes

OBJECTIVE

While typically benign, epidermoid tumors upon rare occasion can undergo malignant transformation, which carries a poor prognosis. Here, we reviewed treatment strategies and analyzed outcomes for every case of malignant epidermoid tumor reported since its original description in 1912.

METHODS

A comprehensive literature review identified all reported cases of malignant transformation of intracranial epidermoid tumor. Treatments were categorized as follows: palliative management, stereotactic radiosurgery (SRS), chemotherapy, and surgery plus multiple (2+) adjuvant therapies. Survival data of these groups were compared to treatment outcomes for patients receiving only surgical resection, as reported in our previous study.

RESULTS

We identified 58 cases of intracranial epidermoid tumor with malignant degeneration. Average survival regardless of therapy was 11.8 months. Mean survival outcomes for groups treated with palliative management, chemotherapy, SRS, and multiple postoperative adjuvant therapies were 5.3 months, 25.7 months, 29.2 months, and 36.3 months, respectively. Outcomes for the groups including SRS, chemotherapy, and multiple post-operative adjuvant therapies were statistically significant compared to surgical resection alone.

CONCLUSION

While there remains a lack of consensus regarding the best approach to the management of patients with malignant epidermoid tumors, our systematic analysis characterizes and confirms the added benefit of SRS, chemotherapy, and multimodal adjuvant therapies.

Unusual complications of a benign tumour - our experience with midline posterior fossa epidermoids

Epidermoids of the brain are uncommon benign tumours. Their midline posterior fossa location is exceedingly rare. Fifteen patients with this condition were operated during a 14-year period. Majority of the patients presented in their middle age with mean duration of symptoms of 10 months. Gait imbalance was the commonest symptom observed. Seven patients had features suggestive of raised intracranial tension. Computed tomography scanning showed typical hypodense lesions. On MRI, tumours were hypo-intense on T1 weighted images and hyper-intense on T2 weighted images. All patients underwent microsurgical excision. We encountered certain complications in the post-operative period. This prompted us for a review of our case material and literature and is the basis of the present article. Implications of these findings are discussed.

Survival outcomes for radiotherapy treatment of epidermoid tumors with malignant transformation

Epidermoid tumors are intracranial lesions that may occasionally undergo malignant transformation. Although surgical resection is the first-line treatment for malignant epidermoids, postoperative radiotherapy has been intermittently reported with favorable findings. Our analysis identified all previously reported patients with malignant epidermoids treated with surgical resection alone or surgery plus radiotherapy to examine the potential role for this adjuvant therapy. Whereas patients treated with surgery only had an overall survival of 6.6 months, those treated with postoperative radiotherapy demonstrated a statistically significant increase in survival to 12.7 months (log-rank test, p<0.003). Furthermore, the mean dosage of radiation given to this patient population was 52.2 Gy, with no appreciable survival benefit for the utilization of levels of radiation greater than 50 Gy. When determining the management for malignant transformation of epidermoid tumors, the combination of surgical resection and radiotherapy may be associated with improved short-term survival.

Clinical characteristics and diagnostic imaging of epidermoid tumors

Epidermoid tumors are rare, benign congenital lesions which typically present between the third and fifth decades of life. They are thought to originate from ectodermal cells misplaced during neural tube formation and separation. While epidermoids may present anywhere in the cranial vault, they are characteristically located intradurally and in a paramedian position within the cerebellopontine angle and parasellar regions. Although imaging results may vary depending upon cystic content, CT scanning generally reveals a well-circumscribed, nonenhancing, lobulated, hypodense mass. They are hypointense on T1-weighted MRI, and hyperintense on T2-weighted MRI, diffusion-weighted imaging and fluid-attenuated inversion recovery sequences. The use of appropriate neuroimaging should be utilized to differentiate epidermoids from other intracranial lesions. While gross total resection of these tumors is the definitive treatment to prevent recurrence and aseptic meningitis, a subtotal resection may be necessary to preserve neurological function.

Primary intracranial squamous cell carcinoma in the brain stem with a cerebellopontine angle epidermoid cyst

Primary intracranial squamous cell carcinoma is extremely rare, with most cases arising from a preexisting benign epidermoid cyst. We report a rare case of primary intracranial squamous cell carcinoma in the brain stem with a cerebellopontine angle (CPA) epidermoid cyst. A 72-year-old female suffered from progressive left hemiparesis, difficulty in swallowing, and right hemifacial numbness. Diffusion-weighted magnetic resonance imaging revealed a high signal intensity (SI) lesion in the CPA region and an intra-axially ring-enhanced cystic mass in the right brain stem with low SI. Whole-body positron emission tomography showed no evidence of metastatic disease. The histological findings revealed a typical epidermoid cyst in the CPA region and a squamous cell carcinoma in the brain stem. We speculate that the squamous cell carcinoma may have been developed due to a chronic inflammatory response by the adjacent epidermoid cyst. The patient underwent a surgical resection and radiotherapy. After 12 months, she had no evidence of recurrence.

Primary intracranial squamous cell carcinoma arising in an epidermoid cyst—A case report and review of literature

Primary intracranial squamous cell carcinoma is extremely rare, with most of the cases arising from malignant transformation of an epidermoid or a dermoid cyst. We report here a case of a 45-year-old male patient who presented with 1-month history of intermittent headache and recent onset of altered sensorium. Imaging revealed a midline posterior fossa mass lesion compressing the fourth ventricle and causing hydrocephalus. A provisional diagnosis of dermoid cyst was considered. Histopathological examination revealed a squamous cell carcinoma possibly arising from an underlying epidermoid cyst. This entity is being reported for its rarity.