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

Malignancy and "Violated Neck" Rates in Consecutive Cohort of 79 Adult Patients With Solitary Cystic Neck Mass-Lessons Learned and Recommendations for Clinical Practice Guidelines

OBJECTIVE

The neck region is a common site for solitary cystic neck mass (SCNM) of various etiologies, including congenital, inflammatory, and neoplastic. In adults, the primary focus is excluding malignancy. The objective of this study was to retrospectively analyze the accuracy of available diagnostic technologies for the differentiation of benign and malignant SCNM in adult patients. The study aimed to develop new clinical practice guidelines for evaluating and managing SCNM.

METHODS

The primary predictive variables were the diagnostic utilities of fine-needle aspiration cytology (FNAC), ultrasound (U/S), multislice computed tomography, and magnetic resonance imaging. The study's endpoint was the overall diagnostic accuracy in differentiating between benign and malignant SCNM. The final diagnosis was based on histopathology.

RESULTS

The study included 79 adult patients: 55 (69.62%) male and 24 (30.38%) female ( P <0.05). The mean age at presentation was 42.1 years (range: 18-84 years). Solitary cystic neck mass was distributed in the anterior neck region in 30 (37.97%) patients and the posterolateral neck regions in 49 (62.03%) patients ( P <0.05). The posterolateral neck regions had a significantly higher rate of malignant SCNM than the anterior neck region [19/49 (38.78%) versus 1/30 (3.33%)] ( P <0.05). There was no statistically significant difference between the U/S+FNAC and U/S+FNAC+multislice computed tomography and/or magnetic resonance imaging groups in differentiating benign and malignant SCNM (40/42 versus 36/37, P >0.05). "Violated neck" was recorded in 2 cases.

CONCLUSION

A systematic investigation protocol should be applied to evaluate adult patients with SCNM.

The Riddle of the Double Vision-A Rare Case of Intracranial Tumor: When Imaging Resolves the Mystery

A 77-year-old-man with arterial hypertension, diabetes mellitus type II presented at our clinic for a routine ophthalmological exam. He complained of intermittent double vision. The ophthalmic examination revealed paralysis of III (n. oculomotorius) and VI (n. abducens) cranial nerves with ptosis, deficit in elevation and abduction of the left eye. The patient underwent urgent MRI imaging of the brain/orbits and paranasal sinuses, and urgent neurological assessment. MRI revealed a volume-occupying process, starting from the posterior wall of the left maxillary sinus with perineural diffusion and involvement of the homolateral trigeminal nerve, intracranial spread in the medial cranial fossa and involvement of the cavernous, sphenoidal sinuses and the orbital apex on the left side. Biopsy was performed, and the histology resulted in sinonasal squamous cell carcinoma with intracranial spread.

The imaging dynamic changes in the malignant transformation of an epidermoid cyst: a case report and literature review

Malignant transformation of epidermoid cysts is a rare complication. Most of the previously reported cases have involved postoperative malignant transformations. We present a case of malignant transformation of a nonpostoperative epidermoid tumor into squamous cell carcinoma (SCC) that occurred in a 61-year-old Chinese woman. The patient's initial cranial MRI scan showed an epidermoid cyst with marginal enhancement in the pre-pontine cistern, and the lesion gradually enlarged after 10 months. A craniotomy was performed using to remove part of the tumor via the right retrosigmoid approach, and postoperative pathology confirmed that the transformation of the epidermoid cyst was malignant. Our case study suggests that the possibility of malignant transformation of epidermoid cyst should not be ignored on the basis of enhanced imaging features, regardless of whether they are nodular, annular, or patchy, as is the case for inflammation. Strict follow-up is required for early detection of malignant transformation to prompt correspondingly early clinical treatment.

Orbital Intradiploic Epidermoid Cyst: A Case Report of a Rare Entity

Cranial epidermoid cysts are relatively rare. More frequently reported in middle-aged men with a wide variety of signs and symptoms such as headache, seizures, cerebellar and cranial nerve deficits/visual disturbance. The approach for surgical removal of the cyst depends on its size and location. In addition, a multidisciplinary team must be involved due to the common occurrence of misdiagnosis. We present the unusual age of presentation for intradiploic epidermoid cysts. A 14-year-old boy is complaining of a 2-month history of painless progressive swelling of the right eyebrow. Magnetic resonance imaging revealed an intradiploic cystic mass within the right frontal bone. The cystic mass was removed, and histological examination confirmed the diagnosis of an epidermoid cyst. This case illustrated the potential of developing intradiploic epidermoid cysts in pediatrics.

Imaging of congenital and developmental cystic lesions of the brain: a narrative review

INTRODUCTION

Congenital and developmental intracranial cysts represent a large heterogenous group with varied presentations and etiologies. They can range from normal variants to pathologic lesions often associated with known congenital syndromes or acquired insults. While some are incidentally found, others are symptomatic or may become symptomatic over time. The preferred type of neuroimaging for timely diagnosis helps determine appropriate management and treatment, if indicated.

AREAS COVERED

In this narrative review article, authors present a comprehensive description of developmental cystic lesions. Imaging descriptions are provided for each type of cystic lesion as well as several representative images.

EXPERT OPINION

As advanced neuroimaging techniques become more ubiquitous in clinical use, more light may be shed on the natural history of certain intracranial cystic lesions throughout the lifespan. This includes prenatal imaging for early identification and prognostication to surveillance imaging into advanced age to ascertain associations of certain cystic lesions with age-related cognitive dysfunction.

Spectrum of intracranial and spinal epidermoids including unusual locations and imaging findings: A pictorial review

Intracranial and spinal epidermoids are benign slow-growing congenital lesions. They are predominantly intradural, extra-axial in location, with intra-axial locations (intra-parenchymal and spinal intramedullary) being rare. The most common locations of intradural epidermoids are cerebellopontine angle cistern followed by supra- and para-sellar regions, and fourth ventricle. Less common locations include inter-hemispheric fissure, sylvian fissure, lateral ventricle, intracerebral, velum interpositum cistern, superior cerebellar cistern and pineal gland. They can also be extradural, usually arising in the diploic space of the calvaria, though they are less common. Magnetic resonance imaging is the primary modality for diagnosis and knowing the extent of the lesion. In this pictorial review, we intend to illustrate their classical and unusual locations, atypical imaging findings including calcifications, rare complications like haemorrhage or spontaneous rupture.

Incidental findings on brain magnetic resonance imaging (MRI) in adults: a review of imaging spectrum, clinical significance, and management

Utilization of brain MRI has dramatically increased in recent decades due to rapid advancement in imaging technology and improving accessibility. As a result, radiologists increasingly encounter findings incidentally discovered on brain MRIs which are performed for unrelated indications. Some of these findings are clinically significant, necessitating further investigation or treatment and resulting in increased costs to healthcare systems as well as increased patient anxiety. Moreover, management of these incidental findings poses a significant challenge for referring physicians. Therefore, it is important for interpreting radiologists to know the prevalence, clinical consequences, and appropriate management of these findings. There is a wide spectrum of incidental findings on brain MRI such as asymptomatic brain infarct, age-related white matter changes, microhemorrhages, intracranial tumors, intracranial cystic lesions, and anatomic variants. This article provides a narrative review of important incidental findings encountered on brain MRI in adults with a focus on prevalence, clinical implications, and recommendations on management of these findings based on current available data.

Epidermoid cyst in atypical intracranial areas transformed to epidermoid carcinoma: a case report

Intracranial epidermoid cysts, also known as epidermal cysts, grow slowly and may be occult. When small, epidermoid cysts are usually clinically unremarkable or cause no definitive symptoms. At typical sites, they are easily found through magnetic resonance imaging, which aids evaluation before surgery. However, in rare cases, epidermoid cysts are situated in unusual locations or transformed to malignancy, and preoperative misdiagnosis is possible. Here, the case of a 58-year-old male patient who presented with weakness in the left lower limb and was diagnosed with a malignant epidermoid cyst in the right frontoparietal lobe, right lateral ventricle, is reported. Surgery was performed to remove the tumour followed by radiotherapy, and the patient was reported to be living independently after approximately 11 months of follow-up.

Intracranial squamous cell carcinoma of the cerebello-pontine angle mimicking a cystic acoustic schwannoma. A case report with discussion of differential diagnosis and review of literature

We report a case of a primary intracranial squamous cell carcinoma (SCC) of the cerebello-pontine angle extending through the internal auditory canal, with the unusual presentation of a completely cystic lesion with no diffusion restriction, internal necrotic-hemorrhagic changes and peripheral enhancement, mimicking a cystic acoustic schwannoma. The lack of diffusion restriction and the peripheral enhancement along the lesion, 2 unique findings, supposedly reflected complete cancerization of the epidermoid cyst from which the SCC originated. We discuss the differential diagnosis and review the literature on primary intracranial SCC.

Adenocarcinoma arising in an ectopic enterogenous cyst: A rare case report and review of literature

Enterogenous cyst (EC) is a rare congenital lesion generally located in the central nervous system, such as in the cerebral hemispheres, posterior fossa, or spinal canal. They are usually benign lesions, and malignant transformation is rare. A 42-year-old woman felt an obvious pain in the lump and went to a local hospital for local lumpectomy. After 7 months, she again felt pain in the buttocks and difficulty in urinating and defecation. The computed tomography (CT) scan showed a mass in the pelvis. Sacrococcygeal cyst excision was performed 10 days later, and postoperative pathology showed epidermoid cyst. Shortly after, the patient recovered and was discharged from the hospital; the pain in the buttocks continued to recur. Puncture and drainage were performed five times. Later, the patient went to our hospital for treatment, and pelvic MRI showed multiple abnormal signal shadows in the presacral and sacrococcygeal regions, some of which were considered abscesses, and some were cystic lesions. She underwent tumor resection and was diagnosed with EC with locally moderately differentiated adenocarcinoma. Four months later, the patient's symptoms of swelling and pain recurred. MRI examination showed multiple high-signal T2 shadows in the anterior sacral and subcutaneous tissues of the buttocks, and enhanced scan showed partial marginal enhancement. After assessment, the patient was given a radiation dose of 60 Gy/25F. ECs in the anterior sacral and soft tissue of the buttocks are very rare, and the case of carcinomatous transformation has never been reported. Therefore, we discussed the clinicopathological features of ectopic ECs and reviewed the literature.

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.

Recurrent lumbar intraspinal epidermoid cyst presenting as lower back pain, a case report

INTRODUCTION

Intraspinal Epidermoid Cyst (IEC) is a very-rare, yet one of the most benign tumors of the Central Nervous System (CNS). Very few cases of IEC were reported world-wide. Presentations depend on the location of the tumor with pain being the most common presenting symptom.

CASE PRESENTATION

A-35-year-old patient presented to the neurosurgical department for a regular follow up. Her history dates back to four years ago, when she first presented with back pain, which was later accompanied with fecal and urinary incontinence. Magnetic Resonance Imaging (MRI) showed a tumor at the level of L4-L5 which was surgically removed. Three years later, the patient presented to the clinic with similar symptoms. A repeat MRI showed a mass at L4-L5, which was surgically removed. Histological findings of both surgeries showed findings consistent with IEC. Currently the patient has no complaints.

CLINICAL DISCUSSION

IEC has various presentations. Our case presented with back pain, and urinary and fecal incontinence. Diagnosis depends on imaging and histology. MRI is the imaging modality of choice for those tumors in the CNS. Surgical removal is associated with high recurrence as a result of the suboptimal resection due to the strong adhesions between the capsule and the spinal cord.

CONCLUSION

Pain is the most common presenting symptom for IEC. Adjuvant radiotherapy, which should be implemented in the standard of care, is associated with a lesser degree of recurrence, in addition to regular follow-ups.

Malignant Transformation of Recurrent Residual Cerebellopontine Angle Epidermoid Tumor: Significance of Clinical Vigilance and Long-term Surveillance

Epidermoid tumors (ET) are slow-growing masses where malignant transformations occur extremely rarely. Malignant transformation warning signs are the rapid-onset, progression, and recurrence of symptoms. The radiologic evidence for malignant transformation is contrast enhancement with rapid growth, observed with magnetic resonance imaging (MRI) or computed tomography scans. Here, we provide a case report of a 68-year-old woman with a long-standing history of left-sided cerebellopontine angle ET who presented with a recent worsening of symptoms, and MRI observation of new ET contrast enhancement. Surgical re-exploration and histopathologic confirmation are mandatory in this setting of recent symptom worsening and MRI observation of rapid mass growth.

Asymptomatic rupture of an intracranial dermoid cyst: to intervene or not to intervene?

Dermoid cysts are an exceedingly rare phenomenon inside the cranial vault. These benign, slow-growing lesions can rupture, releasing cyst contents into the ventricular system and subarachnoid space causing pathology in the form of chemical meningitis and vasospasm. Here, we present the case of a 26-year-old man who was investigated for a facial nerve palsy and was incidentally found to have a ruptured dermoid cyst in the pineal region, with dissemination of cyst contents throughout the ventricular system.

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.

Surgery and dose-escalated radiotherapy for a de novo intracranial squamous cell carcinoma of the cerebellopontine angle

We report an extremely rare case of de novo intracranial squamous cell carcinoma of the cerebellopontine angle. The patient underwent craniotomy for debulking of the lesion to relieve mass effect on the brainstem and to establish a tissue diagnosis. Cancer staging revealed no other primary cancers and no evidence of metastatic disease. Postoperatively, he received image-guided intensity-modulated radiotherapy to the tumor bed followed by fractionated radiosurgery boost to the gross residual disease for a total average dose of 7000 cGy. He had a complete response to radiation and remains 42-months' disease-free post-treatment.

A case report of rare intraperitoneal cholesteatoma diagnosed and treated through multidisciplinary collaboration

55‐year‐old female patient with abdominal distension and poor appetite for 3 months was diagnosed as intraperitoneal cholesteatoma by imaging findings and histological tests. Patient has received surgical resection and recovered well after operation.

A novel management proposal for intrinsic brainstem neurenteric cysts: case report

Neurenteric cysts (NCs) are rare congenital lesions with epithelial mucin-secreting walls. They can occur anywhere along the neural axis, and an intrinsic midbrain cyst is extraordinary. Surgical management may pose a challenge due to the location of the lesion and adhesion of the cyst wall to the surrounding brainstem. The authors describe the first case of pediatric NC that was treated successfully with intracystic interferon-α (IFN-α).A 16-month-old baby girl presented with a 2-week history of progressive croup, vomiting, and swallowing difficulty. MRI revealed a 1.8-cm cystic intrinsic lesion in the pontomedullary region. She initially underwent posterior fossa craniotomy and drainage of the cyst under intraoperative neurophysiology monitoring. Three weeks following the procedure, her symptoms recurred, and follow-up MRI demonstrated cystic recurrence. She underwent repeat aspiration of the cyst and biopsy of the cyst wall, and INF-α-2b was injected into the cystic cavity. Her symptoms improved and completely resolved after 5 months. A 9-month follow-up brain MRI study showed complete resolution of the NC. Intracystic IFN-α injection after cystic content aspiration may be a safe treatment option for the management of intrinsic brainstem NCs. Long-term clinical and radiological follow-up is recommended.

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.

Primary Intracranial Squamous Cell Carcinoma Arising in Dermoid Cyst

Primary intracranial squamous cell carcinoma represents a rare entity. However, few cases have been reported in the literature so far. We report the case of a 32-year-old male who presented with a history of severe headache and vertigo for 3 weeks. Magnetic resonance imaging brain with contrast was done that showed a lesion measuring 5 cm × 4.8 cm in the left cerebellum near the midline which was hyperintense on T2 and hypointense on T1. It also showed ring-like heterogeneous contrast enhancement causing midline shift as well as pressure over the brainstem causing severe obstructive hydrocephalus. After emergency ventriculoperitoneal shunt placement, the patient subsequently underwent left paramedian suboccipital craniotomy and excision of space-occupying lesion. Intraoperatively, a well-demarcated capsule was identified. The entire lesion consisting of areas of calcification and hair particles was removed except the part of capsule which was adherent to the brainstem. Histopathology of the lesion showed infiltrating malignant neoplasm exhibiting papillary architecture with thick fibrovascular cores lined by stratified squamous cells. In order to rule out the possibility of metastases, systemic workup was done which yielded negative results.

Genomic profile of a primary squamous cell carcinoma arising from malignant transformation of a pineal epidermoid cyst

Malignant transformation of intracranial epidermoid cysts is a rare occurrence. We present the second case of such an event occurring in the pineal region and the first case sent for detailed genomic profiling. MRI demonstrated two lesions: a cyst in a quadrigeminal cistern with restricted diffusion on DWI-weighted images and an adjacent, peripherally enhancing tumor with cerebellar infiltration. Both the lesions were completely resected with a small residual of the epidermoid cyst. The final pathology of both lesions was consistent with epidermoid cyst and squamous cell carcinoma (SCC), respectively. The tumor specimen was sent for comprehensive genomic profiling which revealed stable microsatellite status and loss of CDKN2A/B, MTAP (exons 2-8), and PTEN (exons 6-9). Although reports of primary SCC originating from the epidermoid cyst have been previously described, this is the first description of the genomic profile of such a tumor.

Intracranial Squamous Cell Carcinoma Arising From a Cerebellopontine Angle Epidermoid Cyst Remnant Four Decades After Partial Resection

Intracranial epidermoid cysts are benign lesions that typically remain asymptomatic; however, although histopathologically benign, these cysts can rarely undergo malignant transformation into squamous cell carcinoma. Primary intracranial squamous cell carcinoma carries a poor prognosis as optimal treatment modalities remain unclear due to their low incidence. Here, we present a case of a cerebellopontine angle epidermoid cyst remnant that underwent malignant transformation into squamous cell carcinoma 40 years after partial resection. To our knowledge, this case establishes the longest time interval to date for an intracranial epidermoid cyst to undergo malignant transformation. We also review the relevant literature and discuss recent retrospective clinical studies that have analyzed the effect of multimodal treatment approaches on survival outcomes in patients with these lesions.

[Intracranial cystic lesions]

CLINICAL PROBLEM

Intracerebral cysts are common findings in imaging of the neurocranium and are not always clinically significant. The pathological spectrum of intracerebral cysts is, however, very broad and in addition to incidental findings includes developmental disorders, malformation tumors, primary and secondary neoplasms and infectious etiologies, such as cerebral abscess formation, cysticercosis or residuals after congenital cytomegalovirus infections. Intracerebral cystic defects may be caused by inflammatory central nervous system (CNS) diseases, such as multiple sclerosis as well as by mitochondriopathies, leukodystrophy, electrolyte disturbances or osmotic demyelination syndrome or brain infarctions, e.g. after lacunar infarctions or as encephalomalacic changes after severe traumatic brain injury.

RADIOLOGICAL STANDARD PROCEDURES

In addition to the radiological findings of cysts in magnetic resonance imaging (MRI) or in computed tomography (CT), the localization, patient age, patient medical history and laboratory diagnostics are helpful for the differential diagnostics.

METHODICAL INNOVATION

In addition to the morphological assessment, advanced MRI techniques, such as diffusion-weighted imaging for epidermoids or the use of MR spectroscopy, can provide valuable information for the differential diagnosis.

PERFORMANCE/ASSESSMENT

Intracranial cysts can be subdivided into intraventricular and periventricular cysts, intra-axial cysts and cysts in the external fluid-filled spaces. Associated tumor nodules and the contrast medium behavior of the cyst walls and/or associated soft tissue components as well as the reaction of the adjacent parenchyma are helpful for the diagnosis and assessment.

Proton beam therapy for malignant transformation of intracranial epidermoid cyst

We report the first clinical case on the successful use of proton beam therapy in the management of malignant transformation of intracranial epidermoid cyst. A 43-year-old man was initially diagnosed as this disease with left facial paresis, hypesthesia and hypoalgesia in the territories of the trigeminal nerve. After failure of surgical interventions, he was referred to our radiation centre. We performed a postoperative proton beam therapy for treatment. We delivered a total dose of 57 GyE in 31 fractions. He tolerated the treatment well with mild acute toxicities and remained healthy and functional by 2-year follow-up postradiotherapy. No evidence of delayed radiation-induced neurotoxicity was observed.

Radiotherapy for recurrent intracranial epidermoid cysts without malignant transformation: a single-institution case series

INTRODUCTION

Recurrent intracranial epidermoid cysts may be difficult to address surgically given their proximity to critical neurovascular structures of the skull base. There are emerging reports of using radiotherapy (RT) for the treatment of recurrent epidermoid cysts. Here, we report a case series of adjuvant fractionated external beam RT for recurrent intracranial epidermoid cysts.

METHODS

A single-institution review of all recurrent epidermoid cysts treated with adjuvant therapy between 2000 and 2017 was performed.

RESULTS

Eight patients with recurrent epidermoid cysts who underwent adjuvant external beam RT were identified. Average age at initial diagnosis was 42.2 years, and median clinical follow-up after initial diagnosis and RT was 16.4 and 2.9 years, respectively. The median number of surgical resections prior to RT was 3 (range 2-5). Rationale for RT included multiple recurrent disease, rapid recurrence following prior resection, increased risk of further surgical morbidity, and patient preference. Median dose was 50.4 delivered in 1.8 Gy fractions (median 28 fractions). By the date of last follow-up, no patient has demonstrated progression, and there have been no cases of malignant degeneration.

CONCLUSION

Adjuvant RT should be considered in the context of recurrent epidermoid cysts to decrease the likelihood of further recurrences.

Malignant Transformation of a Filum Terminale Dermoid Tumor into Adenocarcinoma

BACKGROUND

Intraspinal dermoid tumors are usually rare benign growths that occur as a result of defects during neural tube formation. They make up less than 1% of tumors in the spine and are associated with spinal dysraphisms or sinus tracts. Although rare, malignant transformation into squamous cell carcinoma has been previously reported. Malignant transformation into adenocarcinoma, however, represents a novel phenotypic differentiation pattern that is hitherto undescribed.

CASE DESCRIPTION

A 45-year-old woman presented with acute symptoms of cauda equina syndrome. Imaging of the spine revealed a large intradural sacral mass. The lesion was surgically resected with pathology revealing a dermoid tumor with malignant transformation into adenocarcinoma. Metastatic workup revealed no other suspicious lesions. The patient had an uneventful postoperative course, gradually regaining micturition control.

CONCLUSIONS

Dermoid tumors, also known as benign cystic teratoma or mature teratoma, are usually benign congenital tumors comprising epithelial cells that arise from displaced embryonic ectoderm and mesoderm during neural tube formation. Although extremely rare, malignant transformation into squamous cell carcinoma has been reported. This case represents the first report of an intraspinal dermoid tumor transforming into adenocarcinoma. A comprehensive histopathologic analysis is key to identifying the lesion and guiding postsurgical management.

Cranial Nerve Preservation Following Surgical Treatment for Epidermoid Cysts of the Posterior and Middle Fossae

Epidermoid cysts are rare lesions, accounting for 0.2 to 1.8% of all intracranial tumors. They most commonly occur in the cerebellopontine angle where they may cause a breadth of neurologic complications due to mass effect on the nearby cranial nerves (CN), vascular structures, and the brain stem. Treatment of epidermoid cysts is surgical, with the goal of complete resection using microsurgical technique and even more importantly preservation of the involved CNs, vasculature, and brain parenchyma. Successful surgery can result in total resolution of symptoms, but, in certain situations, may not be advisable due to adherence, scarring, or inflammation making dissection of CN fascicles difficult and possibly hazardous. We conducted a retrospective review from 1998 to 2016 and compiled a series of 28 skull base epidermoid cysts operated on at our institution. Cases were evaluated for presenting symptoms, history of prior resection, and postoperative results including CN function, extent of resection, residual tumor, and need for reoperations. The average tumor size (largest diameter) was 3.9 cm with a range of 1 to 7cm. Eighteen of twenty-eight (64%) patients underwent a gross total resection and ten underwent subtotal resection. No patients, whether presenting with CN deficits or not, experienced permanent worsening of CN function following surgery. Complete resection of epidermoid cysts should remain a high priority of therapy, but, in our opinion, preservation of CN function should be a primary goal, determining the extent of resection to provide patients with the highest quality of life possible following surgery.

Long-term Seizure Disorder Caused by a Dermoid Cyst with Catastrophic Developments

Glioblastoma multiforme (GBM) is a World Health Organization (WHO) grade IV primary malignant astrocytoma. Aneurysms are devastating intracranial neurovascular pathologies. Intracranial dermoid cysts are common, benign lesions which can be clinically silent or associated with seizure disorder. We describe physically adjacent diagnoses of dermoid cyst, intracranial aneurysm, and GBM in a single patient. Records were collected and reviewed to compile the final clinical picture. A 72-year-old male with a long history of seizure disorder, presented with new focal, unilateral neurological deficits. Radiographic evaluation including computed tomography (CT) and magnetic resonance imaging (MRI) demonstrated a dermoid cyst with an underlying developing GBM, which also, by happenstance, contained an aneurysm. During open surgical resection, multiple macroscopically distinct tissue types were noted. Histological analysis of tissue from each lesion confirmed the diagnoses including dermoid cyst, GBM, and aneurysm. Pathological analysis revealed the presence of extensive inflammatory cells throughout. Subsequent staining identified CD68 positive cells indicating a probable chronic inflammatory state. Chronic inflammation resulting from the presence of a long term dermoid cyst and ongoing seizures may have led to dystrophic changes in adjacent vasculature and approximating glial tissues, inducing the formation of an aneurysm and a secondary GBM. Therefore, while benign in nature, dermoid cysts can be related to seizure disorder and may cause chronic inflammation in surrounding brain tissue.

Combined microsurgical and endoscopic technique for removal of extensive intracranial epidermoids

Background

Intracranial epidermoid tumors are challenging lesions because they grow along the subarachnoid spaces around delicate neurovascular structures and often extend from one compartment to another. The purpose of this study was to determine the usefulness of endoscopic assistance in the microsurgical resection of these lesions, in which total resection is therapy of choice.

Methods

A total of 48 cases of intracranial epidermoids were treated by combined microscopic and endoscopic techniques. Initially, the tumor was removed under the microscope and after ensuring maximum excision, the endoscope was used to find out and excise any residual tumor.

Results

Out of these 48 cases complete excision was achieved in 44 cases and subtotal excision in four patients. Postoperative complications were seen in 17 patients, but none of the complications was attributed to the use of endoscope. Overall use of endoscope benefited 79% of cases.

Conclusion

We recommend combined microsurgical and endoscopic approach to achieve complete/maximum resection of extensive intracranial epidermoid tumors.

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.

Suprasellar keratinous cyst: A case report and review on its radiological features and treatment outcome

BACKGROUND

Keratinous or epidermoid cysts (ECs) are encapsulated lesions lined by squamous cell epithelium. They comprise approximately 1% of intracranial lesions. Contrary to dermoid cysts, they lack dermal elements such as sebaceous or apocrine glands and hair follicles. The sellar region is the second most common intracranial site following the cerebellopontine angle. Here, we report a case of EC in a patient who complained of endocrine disturbances. We also performed a systematic review on previously published cases to analyze clinical and radiological characteristics and report the treatment outcomes of suprasellar ECs.

CASE DESCRIPTION

A 42-year-old woman presented with a one-year history of amenorrhea, weight gain, severe headache, and visual disturbances for 6 months. Work-up identified an elevated prolactin level and a temporal field defect of the right eye. Magnetic resonance imaging (MRI) showed a cystic suprasellar lesion pushing on the optic chiasm. She underwent endoscopic trans-sphenoidal surgery, which confirmed a keratinous cyst on histology. Postoperatively, complete resection was confirmed on imaging. She did well although her hospital stay was prolonged due to diabetes insipidus and hypocortisolism.

CONCLUSION

Chronic endocrine disturbances can be the presenting complaints of a suprasellar EC, whose T1-weighted MRI appearance can be non-specific, mimicking other differential diagnoses, such as a Rathke's cleft cyst. However, the T2-weighted MRI appearances of ECs are generally hyper-intense and lesions show diffusion restriction. Treatment is surgical and yields good outcomes in most cases reported.

Repeated recurrent epidermoid cyst with atypical hyperplasia: A case report and literature review

RATIONALE

Epidermoid cysts are slow-growing, benign tumor which account for less than 1% of all intraspinal tumors and epidermoid cyst with Atypical Hyperplasia is very rare. Surgical resection is the standard treatment of the tumor, but recurrence is not uncommon after incomplete resection. Inappropriate treatment can lead to repeated recurrent. Here, we reported a case of repeated recurrent epidermoid cyst with atypical hyperplasia treated with radiotherapy after surgery.

PRESENTING CONCERNS

A 40-year-old female presenting with intraspinal epidermoid cyst showed incomplete paraplegia in lower limbs.

DIAGNOSIS

Back pain reappeared 19 months later after surgical treatment. The patient suffered marked weakness in both limbs, along with obvious muscle atrophy and sensation deficiency of warmth and pain in left lower limb. MRI demonstrated a cystic mass with solid content and peripheral strengthen in enhanced scan.

INTERVENTIONS

Extended excision with intraoperative local chemotherapy and postoperative radiotherapy was performed and a dramatic reversal of symptoms was gained 4 weeks after surgery, with a total dose of 46 Gy. Postoperative pathological examination revealed epidermoid cyst with mild to moderate atypical hyperplasia.

OUTCOMES

No acute side effects of the treatment were reported. Back pain obviously alleviated within 48 hours after surgery, while weakness and numbness of the lower limbs gradually improved and nearly disappeared in the 3-monthly follow-up visit. Until now, no recurrence is found during the 5-years follow-up.

LESSONS

Our study highlights that incomplete excision has led to repeated recurrent epidermoid cyst, but its complete removal with adjuvant radiotherapy has achieved remission of symptoms. Atypical hyperplasia discovered by pathological examination reminds us the possibility of malignant transformation and ensures the necessity of adequate treatment.

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 squamous cell carcinoma arising in a previously resected cerebellopontine angle epidermoid

Background:

Malignant squamous cell differentiation of an epidermoid cyst can carry a significantly poor prognosis and very little is known about this entity.

Case Description:

We present the case of a 35-year-old lady, with primary malignant squamous cell carcinoma (SCC) arising from a previously partially resected cerebellopontine angle epidermoid cyst almost 5 years after initial resection. We also review the relevant literature.

Conclusion:

The imaging findings, histopathology, and management of a malignant SCC arising from a benign epidermoid cyst are discussed with recommendation for increased surveillance and follow-up, even for classically accepted benign lesions.

Sellar and Parasellar Imaging

The skull base is a complex anatomical region that harbors many important neurovascular structures in a relatively confined space. The pathology that can develop at this site is varied, and many disease processes may present with similar clinical and neuroimaging findings. While computed tomography maintains a role in the evaluation of many entities and can, for instance, delineate osseous erosion with great detail and characterize calcified tumor matrices, magnetic resonance imaging (MRI) is the mainstay in the neuroimaging assessment of most pathology occurring at the skull base. Various MRI sequences have proven to be robust tools for tissue characterization and can provide information on the presence of lipids, paramagnetic and diamagnetic elements, and tumor cellularity, among others. In addition, currently available MRI techniques are able to generate high spatial resolution images that allow visualization of cranial nerves and their involvement by adjacent pathology. The information obtained from such examinations may aid in the distinction of these disease processes and in the accurate delineation of their extent prior to biopsy or treatment planning.

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.

Recurrent intracranial neurenteric cyst with malignant transformation: A case report and literature review

Neurenteric cysts (NCs) are uncommon congenital cystic lesions. Malignantly transformed NCs are extremely rare. The present study reports the case of a recurrent foramen magnum NC with a malignant transformation and reviews 8 previously reported cases. A 58-year-old woman with a 5-month history of occasional headaches, dizziness and vomiting presented to the Beijing Tiantan Hospital (Beijing, China) with palsy of the left cranial IX and X nerves, decreased sensation in the limbs on the right side and an ataxic gait. Magnetic resonance imaging (MRI) scans revealed a cystic mass in the left side of the foramen magnum, positioned anteriolaterally to the medulla oblongata. Surgery using a left suboccipital retrosigmoid approach was performed. The lesion was partially resected and was histopathologically diagnosed as an NC with focal hyperplasia of the epithelial cells. Additional MRI scans that were performed 25 months later revealed a solid lesion posterior to the medullar oblongata. Therefore, surgery using a suboccipital midline approach was performed. The solid lesion was sub-totally removed and was histopathologically diagnosed as a well-differentiated papillary adenocarcinoma. At 1 month post-surgery, the patient's condition worsened, eventually resulting in mortality due to respiratory failure. Based on the findings of the present case and previous literature, strict criteria for malignant-transformed NCs were created. The location distribution of malignant-transformed NCs does not coincide with the location distribution of all NCs, and malignantly transformed NCs usually occur in adult patients and present as atypical radiological features. Surgery is the optimal treatment for malignantly transformed NCs, and the effectiveness of adjuvant therapy requires additional studies.

Non-metastatic squamous cell carcinoma within a Rathke's cleft cyst

INTRODUCTION

Primary intracranial and sellar squamous cell carcinoma is an extremely rare entity, usually caused by malignant transformation of epidermoid cysts, or very rarely other non-malignant epithelial cysts. Malignant transformation of a Rathke's cleft cyst has never been described.

CASE DESCRIPTION

We present a 49-year-old male patient who presented with a 3-month history of progressive frontotemporal headaches. Imaging revealed a 1.2 cm cystic pituitary mass consistent with a hemorrhagic Rathke's cleft cyst. The patient underwent trans-sphenoidal resection of the pituitary cyst, and pathologic analysis revealed a squamous cell carcinoma lining a Rathke's cleft cyst. Extensive imaging and otorhinolaryngologic evaluation revealed no primary source for metastasis.

CONCLUSIONS

We feel this represents the first case of a patient with a pituitary lesion in which presentation and MRI imaging were consistent with Rathke's cleft cyst, yet histology revealed squamous cell carcinoma in situ.

Primary Intracranial Epidermoid Carcinoma with Diffuse Leptomeningeal Carcinomatosis: Report of Two Cases

BACKGROUND

Malignant degeneration of epidermoid cyst (EC) with accompanying leptomeningeal carcinomatosis (LC) at presentation is extremely rare. We add two cases to the literature, including the first case of primary brainstem involvement with simultaneous diffuse LC, and discuss clinical and radiological cues to differentiate benign and malignant epidermoid tumors for early diagnosis.

CASE DESCRIPTION

The first patient in this report was a 54-year-old woman with recurrent aseptic meningitis and hydrocephalus. Imaging revealed a prepontine and parapontine extra-axial EC with an intra-axial brainstem ring-enhancing cystic lesion, diffuse leptomeningeal enhancement, and intradural extramedullary nodular deposits throughout the spine. Surgical decompression of the cysts confirmed the diagnosis of invasive primary squamous cell carcinoma of the brainstem and benign epidermoid tumor of the cerebellopontine cistern. The second patient was a 37-year-old woman with extensive left-sided cranial neuropathies. Imaging revealed prepontine and parapontine enhancing and nonenhancing deposits along multiple cranial nerves and diffuse leptomeningeal nodular enhancement in the thoracolumbar spine. A biopsy confirmed the diagnosis of infiltrative, poorly differentiated carcinoma adjacent to a benign EC. Both patients underwent systemic screening to rule out metastatic disease.

CONCLUSIONS

These cases illustrate that a high index of clinical suspicion is necessary for early diagnosis of disseminated disease in cases of recurrent episodes of aseptic meningitis. In cases of primary benign EC, aggressive resection should be attempted to reduce the risk of malignant degeneration. A separate biopsy specimen from the enhancing portion of the tumor is used to rule out an underlying coexisting malignancy. Multimodal management carries the best prognosis for primary intracranial squamous cell carcinoma with LC.

Imaging Findings of an Epidermoid Cyst Undergoing Malignant Transformation

Malignant transformation of epidermoid cyst into squamous cell carcinoma (SCC) is rare. We report the case of a 39-year-old woman presenting with dizziness and cerebellar ataxia. MR scan revealed a mass in the left cerebropontine angle compressing the brainstem and the cerebellum, with two main components, a cystic and a solid one. The cystic component displayed imaging findings consistent with an epidermoid cyst. The solid component showed dense calcifications, low signal intensity on T1W, T2W and DW images and peripheral nodular enhancement. MR spectroscopy detected high lipid/lactate peaks and choline/creatine ratio. Imaging findings raised suspicion for malignant transformation, which was confirmed by histopathologic examination revealing an SCC. MR imaging with intravenous administration of gadolinium, DW images and MR spectroscopy can play a critical role in the diagnosis of malignant transformation of an epidermoid cyst.

Intracranial cystic lesions: a review

Cysts and cystic-appearing intracranial lesions are common findings with routine cerebral imaging examination. These lesions often represent a challenge in diagnosis. Intracranial cystic lesions have wide pathologic and imaging spectra, of which some require an aggressive and tailored treatment, whereas many others remain asymptomatic and do not require follow-up or intervention. Intracranial cysts can be divided in non-neoplastic lesions that are often of developmental origin but comprise as well infectious cysts and neoplastic lesions that include benign cysts associated with low-grade tumors and cysts as a component of higher grade neoplasms. Reviewed are the pathology, origin, radiologic appearance, differential diagnosis, and therapeutic aspects of intracranial cystic lesions.

Surgery and outcomes of six patients with intradural epidermoid cysts in the lumbar spine

Study design

This was a retrospective study.

Objective

The aim of this study was to analyze the clinical characteristics and discuss the treatment options for epidermoid cysts in the lumbar spine.

Summary of background data

Epidermoid cysts are rare benign neoplasms, which account for less than 1% of all intraspinal tumors. Due to their rarity, there are only a few case reports in the literature. Complete excision is the recommended treatment for an epidermoid cyst, but this is difficult to achieve in the spine. In spite of their benign nature, local recurrence is not uncommon for spinal epidermoid cysts after incomplete excision.

Methods

Six patients with an epidermoid cyst in the lumbar spine underwent surgical treatment in our center between 2004 and 2011. A total excision using microsurgical techniques and reconstruction was successfully undertaken in all patients. Clinical data and detailed pathologic results were retrospectively analyzed. All cases were followed up for a median time of more than 4 years. The clinical data and surgical efficacy were analyzed to suggest treatment options for epidermoid cysts in the lumbar spine on the basis of a literature review and our own experience.

Results

The mean age of the patients in this study was 37.7 years and the mean duration of pre-operative symptoms was 29.7 months (2 to 120 months). All patients were disease-free during their follow-up period. Radicular pain nearly disappeared, and patients suffering from neurologic deficits and defecation disorders recovered well.

Conclusions

Although an epidermoid cyst is a benign tumor, it is apt to recur locally following inadequate removal. Therefore, complete excision with preservation of neural function is an ideal protocol for intraspinal epidermoid cysts. Microsurgical techniques are very useful.