Diffusion-weighted MRI of an intracranial epidermoid with malignant transformation

Radio-pathological characteristics of malignant transformation of an epidermoid cyst in the cerebellopontine angle: A case report

Background

Intracranial epidermoid cysts are rare congenital neoplasms that are clinically indolent and histologically benign. They rarely show malignant transformation, and several such cases have been reported. Some radiological features that suggest malignant transformation have been reported. However, histopathological features that indicate a high risk of malignant transformation have not been reported to date.

Case Description

We report a 59-year-old woman with a benign epidermoid cyst in the cerebellopontine angle that showed malignant transformation after 6 years. Magnetic resonance imaging (MRI) at the time of initial onset displayed a high-intensity signal on diffusion-weighted imaging (DWI), no peritumoral edema, and no enhancement on contrast-enhanced T1-weighted imaging. On the other hand, MRI at the time of malignant transformation showed a low-intensity signal on DWI, peritumoral edema, and enhancement of the tumor capsule on contrast-enhanced T1-weighted imaging. Pathological findings at the time of the first surgery differed from normal benign epidermoid cysts, in that stratified squamous epithelial metaplasia was observed, and immunohistochemical (IHC) analysis showed positive p53 staining. In addition, IHC analysis at the time of malignant transformation demonstrated positive p16 staining.

Conclusion

In benign epidermoid cysts, it is considered to cause malignant transformation when squamous metaplasia or p53 mutation is observed. Therefore, strict follow-up is required while paying attention to the characteristic changes in MRI for early detection and timely treatment of malignant transformation.

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.

Microsurgical Treatment of Epidermoids. Case Report and Literature Review

The aim of the research: study the features of surgical treatment of epidermoids.

Materials and methods. We present a literature review and the clinical case of surgical treatment of a patient with epidermoid. We have searched medical databases: Medline, Russian Science Citation Index, EMedicine, United Medical Knowledge Base. We considered the features of the clinic, diagnosis, and surgical intervention. The article presents a clinical example of successful surgical treatment of a patient with an epidermoid cyst of the posterior cranial fossa. The result of the literature review was the writing of a clinical lecture; the current state of the issue of etiopathogenesis, diagnosis and management of patients with epidermoids was studied.

Results. The authors found that total microsurgical removal is the method of choice, and the operative technique should be aimed at preventing postoperative aseptic meningitis. Although it was not possible to establish the cause of the development of aseptic meningitis, the authors assume that the mechanism of its formation lies in the self-breaking of the capsule of the epidermoid cyst, probability of which was confirmed by a number of studies. Further study of this pathology is a promising direction in neurosurgery.

Conclusion. Difficulties in the diagnosis and choice of surgical tactics point at the need for detailed preoperative planning of surgical intervention, performing a precise total removal of a lesion with compliance with preventive measures for aseptic meningitis to improve clinical results and reduce the incidence of perioperative complications.

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.

Malignant transformation of an epidermoid cyst in the temporal and prepontine region: Report of a case and differential diagnosis

Malignant transformation of an epidermoid cyst is rare. The current report presents a case of a 55-year-old female patient with squamous cell carcinoma arising from a benign epidermoid cyst in the left temporal region and prepontine area. She had undergone subtotal resection of an epidermoid cyst 7 months previously. Preoperative imaging findings included a focal enhancing area adjacent to the lesion. Postoperative computed tomography demonstrated an increase in the size of the enhancing area. The patient underwent removal of the lesion and postoperative histological examination revealed a squamous cell carcinoma possibly arising from the epidermoid cyst. Accurate diagnosis of malignant transformation prior to operation is difficult; however, the possibility of an intracranial epidermoid cyst must be considered if a focally enhancing area is visible. Postoperative histological examinations may be used to determine a definite diagnosis, and accurate diagnosis is important for planning a rational therapeutic strategy.

Malignant transformation of an intramedullary epidermoid cyst in the thoracic region of the spinal cord

Malignant transformation of epidermoid cysts (ECs) to squamous cell carcinomas (SCCs) in the CNS is exceedingly rare and has only been described in intracranial ECs. In this article, the authors describe a 53-year-old man with a history of a previously resected T3–4 EC, who presented with a 2-month history of progressively worsening weakness in the left side of his body. Magnetic resonance imaging revealed an enhancing mass in the T3–4 region, the exact location of the previous cyst. The mass was resected in gross-total fashion, and pathological analysis revealed an SCC. Postoperatively, the patient regained full strength in his lower extremities. After the resection, he received radiotherapy administered at an isodose of 50 Gy. To the authors' knowledge, this is the first reported case of malignant transformation of an intramedullary spinal EC in the literature.

Primary intracranial basaloid squamous cell carcinoma: an enigma

Primary intracranial squamous cell carcinoma is extremely rare, with most cases arising from malignant transformation of dysembryogenetic lesions such as epidermoid and dermoid cysts. Intracranial squamous cell neoplasm arising de novo is even rarer and has been reported in only four patients to date. We herein describe a case of primary intracranial squamous cell carcinoma arising de novo in the right frontal lobe in a 35-year-old woman treated with a combination of surgery and postoperative conformal radiation. We have also shed light on the biology and the therapeutic options of this enigmatic tumour.

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.

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.

Malignant transformation six months after removal of intracranial epidermoid cyst: a case report

Intracranial epidermoid cysts are uncommon benign tumors of developmental origin; malignant transformation of benign epidermoid cysts is rare, and their prognosis remains poor. We report a case of squamous cell carcinoma arising in the cerebellopontine angle. A 52-year-old man presented with left facial paralysis and cerebellar ataxia. He had undergone total removal of a benign epidermoid cyst six months previously. Postoperative magnetic resonance imaging of the brain revealed a heterogeneous and cystic lesion in the left cerebellopontine angle with hydrocephalus. The cyst wall was enhanced by gadolinium. He underwent ventricle-peritoneal shunt and removal again; the histopathological examination revealed a squamous cell carcinoma possibly arising from an underlying epidermoid cyst. This entity is being reported for its rarity. The presence of contrast enhancement at the site of an epidermoid cyst combined with an acute, progressive neurological deficit should alert the neurosurgeon to the possibility of a malignant transformation.

Malignant transformation 20 years after partial removal of intracranial epidermoid cyst--case report

A 74-year-old woman presented with malignant progression of remnant epidermoid cyst manifesting as sudden onset of right ptosis and double vision. She had right oculomotor nerve paresis. She had a history of surgery for right cerebellopontine angle epidermoid cyst 20 years previously. T(1)-weighted magnetic resonance (MR) imaging demonstrated a hypointense mass lesion in the right cerebellopontine angle and basal cistern, and an isointense mass in the right paraclinoid region which was strongly enhanced. Diffusion-weighted MR imaging showed hyperintense areas in the right cerebellopontine angle, ambient cistern, and basal cistern, and the paraclinoid mass as hypointense. Surgery was performed using Dolenc's approach. Histological examination revealed that the paraclinoid tumor adjacent to the epidermoid tumor remnant was malignant transformation of epidermoid cyst into squamous cell carcinoma. She was treated with 46 Gy linac radiotherapy. She has been without tumor recurrence for 17 months. Malignant change of epidermoid cyst is extremely rare, but rapid progress of the symptoms suggests malignant transformation. MR imaging with gadolinium is useful for diagnosis.

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.

MRI findings of malignant transformation of epidermoid cyst: case report

Malignant transformation of epidermoid cysts into squamous cell carcinoma (SCC) rarely occurs. A 67-year-old man initially presented with an 8-year history of right trigeminal neuralgia. His symptoms had changed into right facial anesthesia with right-ear hearing impairment 8 months before first consulting a neurosurgeon at our hospital. Results obtained using MRI suggested an epidermoid cyst in the right cerebellopontine angle, but showed atypical findings of a small enhancing nodule in the periphery and surrounding edema in the cerebellum and pons. Surgery was performed to remove the mass, but a small nodule was not reached. Despite stereotactic radiosurgery, the patient's clinical course deteriorated; he died 13 months after the first MRI examination. Autopsy revealed SCC originating from the epidermoid cyst. We present serial MRI and pathologic findings in the early and terminal phases of this patient.

Malignant transformation of intra-cranial epithelial cysts: systematic article review

INTRODUCTION

Epidermoid and dermoid cysts are among the most benign intra cranial tumors. Their malignant transformation into squamous cell carcinoma is rare. The authors reviewed the literature.

MATERIALS AND METHODS

MEDLINE and SCIENCE DIRECT searches, and examination of the references in the selected articles yielded 74 patients, 52 of whom fulfilled Garcia's criteria and were selected for the study. Survival analyses were performed to determine whether survival differences were of statistical significance, and P < 0.05 was considered as significant.

RESULTS

Malignant transformation is characterized by a rapid onset of symptoms, recurrence, leptomeningeal carcinomatosis (LC), and tumor enhancement at Computed Tomography Scan or Magnetic Resonance Imaging (87.8 showed this radiological feature). In this review, the SCCs were classified in five groups: (1) Initial malignant transformation of a benign cyst; (2) malignant transformation from a remnant cyst; (3) malignant transformation of a dermoid and epithelial cyst; (4) malignant transformation with leptomeningeal carcinomatosis; (5) other malignancies arising from benign cysts. The median survival was 9 months. Statistics show that LC was of poor prognosis and radiotherapy, although not statistically significant, seems effective against such lesions, with a median survival of 26 months as opposed to 3 months (P=0.077).

CONCLUSION

Although rare, malignant transformation of intracranial epithelial cysts has a poor prognosis and surgery followed by radiotherapy seems to be the best therapeutic modality.