Endodermal cyst of the quadrigeminal cistern: case report.

BACKGROUND: Endodermal cysts usually develop in the subdural space in the anterior spinal cord and rarely occur inside the cranium. Most intracranial endodermal cysts develop in the posterior fossa. We report the first case of an endodermal cyst in the quadrigeminal cistern. CASE DESCRIPTION: The patient was a 71-year-old man who suffered from gait disturbance for 6 months. Although head computed tomography (CT) scanning 4 years previously did not show any cystic lesion, CT and magnetic resonance imaging (MRI) on admission showed a cystic lesion extending from the quadrigeminal cistern to the right ambient cistern. The cyst was subtotally removed via a suboccipital transtentorial approach. The cyst wall consisted of a layer of columnar epithelium and connective tissue. Based on the results of immunostaining, it was diagnosed as an endodermal cyst. CONCLUSIONS: It is possible that the increase of secretion from the cells lining the cyst may have caused a difference in osmotic pressure between the cerebrospinal fluid and the cyst contents, leading to rapid enlargement of the cyst. An endodermal cyst should be removed as completely as possible because its cells have the ability to grow and produce secretions.     

Endoscopic fenestration of posterior fossa arachnoid cyst for the treatment of presyrinx myelopathy--case report

A 32-year-old man presented with an arachnoid cyst of the posterior fossa manifesting as cervical syringomyelic myelopathy. Magnetic resonance (MR) imaging demonstrated edematous enlargement and T2 prolongation of the cervical spinal cord, indicating a "presyrinx" state. MR imaging showed the inferior wall of the cyst, which disturbed cerebrospinal fluid (CSF) pulsatile movement between the intraspinal and intracranial subarachnoid spaces. The cyst wall was fenestrated with a neuroendoscope. The presyrinx state and the CSF movement improved. Posterior fossa arachnoid cyst, as well as Chiari malformation, can cause CSF flow disturbance at the craniocervical junction and syringomyelia. Endoscopic fenestration is less invasive than foramen magnum decompression and should be the procedure of choice.     

Supratentorial neurenteric cyst with spontaneous repetitive intracystic hemorrhage mimicking brain abscess: a case report

Neurenteric cyst (NC) is a benign epithelial cyst (BEC) of endodermal origin that mostly occurs in the spinal subdural space or posterior cranial fossa. A 28-year-old male presented with a left frontal lobe NC associated with spontaneous repetitive intracystic hemorrhage, which was initially diagnosed and treated as a brain abscess. He presented with headache and disorientation, without underlying diseases. A cystic tumor was suspected because of a hypointense signal on diffusion-weighted magnetic resonance imaging (MRI). One day after admission, his condition deteriorated rapidly and emergency cyst aspiration was performed. A brown viscous liquid like bloody pus comprising many neutrophils and macrophages was obtained. Although culture was negative, we initially started antibiotic treatment because of cyst content characteristics and rapid clinical course compatible with brain abscess. He was discharged without neurological deficits, but occasionally complained of intense headache. Computed tomography/MRI showed repetitive intracystic hemorrhage and gradual re-enlargement of the lesion. He underwent radical cyst excision by frontal craniotomy 34 months after aspiration. The pathological diagnosis was NC. We believe this is the first report of a supratentorial NC with spontaneous repetitive intracystic hemorrhage. BECs, especially with intracystic hemorrhage, are difficult to be distinguished from brain abscesses. In cases of cystic lesions or presumed brain abscesses refractory to treatment with aspiration and/or antibiotics, BECs should be considered, and radical cyst wall removal should be considered a treatment option.     

Lateral supratentorial endodermal cyst: case report and review of literature

OBJECTIVE AND IMPORTANCE: Epithelial cysts of the central nervous system are unusual entities, with the majority reported to occur in the spinal canal. More unusual is the intracranial presentation, which shows a predilection for midline localization in the posterior fossa, brainstem, and suprasellar regions. This report discusses the differential diagnosis, pathogenesis, radiographic presentation, and therapeutic considerations of a laterally positioned cerebral convexity endodermal cyst. CLINICAL PRESENTATION: A 49-year-old right-handed man presented with approximately a 30-month history of short- and long-term memory difficulties. A magnetic resonance imaging study revealed a large, nonenhancing, extra-axial cystic lesion overlying the right lateral frontal convexity. INTERVENTION: A right frontoparietal craniotomy exposed a large extra-axial cyst with an opaque, yellowish-white membrane containing a mucoid fluid. Histological analysis disclosed a layer of unremarkable, ciliated columnar epithelium with a basement membrane that stained positive for cytokeratin, periodic acid-Schiff, and Alcian blue. No evidence of either a muscular or cartilaginous layer around the mucosa was present to further delineate neurenteric versus bronchogenic origin of the cyst. CONCLUSION: This case involved the occurrence of a solitary endodermal cyst as an extra-axial mass localized over the lateral frontal lobe. The lateral supratentorial localization of this lesion illustrates the need for consideration of the pathogenesis of this entity as well as its diagnostic differentiation from other cystic abnormalities in this region. A review of the histochemistry of endodermal, neuroepithelial, and other cerebral cysts is presented.     

Extradural endodermal cyst of posterior fossa: case report, review of the literature, and embryogenesis

OBJECTIVE AND IMPORTANCE: Posterior fossa endodermal cysts are rare. They are located in the midline, in ventral or ventrolateral locations, or intrinsic to the neural axis. Accordingly, various theories of embryogenesis have been proposed. We report the first case of an extradural, dorsolaterally situated endodermal cyst. CLINICAL PRESENTATION: An adult male patient presented with a short history of headache and cerebellar ataxia. Neuroimaging revealed an extra-axial cystic posterior fossa mass. INTERVENTION: An entirely extradural cyst was found and was totally excised. Immunohistochemistry confirmed the diagnosis of endodermal cyst. CONCLUSION: The extradural, dorsal location of the endodermal cyst suggests gaps at the cranial end of the notochord causing ectodermal-endodermal adhesions during early gastrulation and the persistence of endodermal remnants in the dorsal mesenchyme of the blastemal cranium. The literature is reviewed, and proposed theories of embryogenesis are discussed.     

Retrorectal epidermoid cyst in an elderly woman: Report of a case

An epidermoid cyst is a common occurrence in the skin. Such a cyst occurring in the retrorectal space, however, is extremely rare. We herein present a case of retrorectal epidermal cyst in a 67-year-old Japanese woman. She reported no symptoms and a perirectal mass behind the lower rectum was accidentally detected by computed tomography (CT). Contrast CT and magnetic resonance imaging revealed a cystic mass (76 x 70 x 63 mm) with a slightly enhanced thin wall which was attached to the lower rectum. The patient underwent surgery via a posterior approach. The mass was exposed after an excision of subcutaneous fat and was firmly adhered to the anal sphincter muscle. The cystic mass was completely removed without a proctectomy. Histologically, the cyst was diagnosed to be an epidermoid cyst. The postoperative course was uneventful, and the patient was discharged on postoperative day 9. A diagnosis of retrorectal cystic tumor is difficult, and a complete resection is necessary for the treatment of such tumors.     

Cerebellar hemangioblastoma simulating arachnoid cyst on imaging and surgery

A case of posterior fossa hemangioblastoma simulating arachnoid cyst on imaging and peroperatively is presented. In vivo proton MR spectroscopy showed evidence of large lactate and resonance at 2.37 ppm not observed earlier in the cystic lesions, including arachnoid cyst. The demonstration of this resonance may help in characterization of these lesions that may be confused with arachnoid cysts on imaging and during surgery. Electronic Publication     

An intradural arachnoid cyst of the craniovertebral junction; a case report]

An intradural arachnoid cyst of the craniovertebral junction possibly of traumatic origin is reported. A 59-year-old man was admitted to our hospital with a 10-month history of progressive gait disturbance. He had a history of head injury with a fracture of the occipital bone. Myelography revealed pooling of the contrast medium in the posterior fossa and on the dorsal sides of C1 and C2. Metrizamide-enhanced computed tomography also showed pooling at the same level. Magnetic resonance imaging indicated a large cystic lesion at the craniovertebral junction. Craniectomy of the posterior fossa and laminectomy of C1, C2 and C3 were performed, and an intradural cyst with thickened dura and arachnoid was found. The cyst wall was opened to communicate with the subarachnoid space. Histological findings of the specimen showed that the arachnoid was thickened. There are over 130 reports of intradural arachnoid cyst of the spine, but those of traumatic origin are rare, and cysts located in the intracranial to spinal region are extremely rare.     

A case of cervical endodermal cyst

A very rare case involving an endodermal cyst of the cervical spinal canal was documented. In 1999, a 28-year-old male presented with mild tetraplegia due to a traffic accident and consequently, he was admitted to another hospital. Magnetic resonance imaging (MRI) performed at that time demonstrated a cervical cord cyst. He was treated conservatively and as a result, complete resolution of symptoms was achieved. Five years later, he presented with progressive right hemiparesis and was referred to our institute. MRI at the time of admission exhibited an intradural extramedullary cystic lesion on the ventral side of the spinal cord at the C5-6 levels, which was characterized by low intensity on T1-weighted, and by high intensity on T2-weighted images. The cyst, which had increased in size, compressed the spinal cord remarkably backward. The anterior central vertebrectomy approach was performed. Subtotal resection of the cyst wall was conducted due to its tight partical adhesion to the spinal cord. The vertebral defect was reconstructed with an autogenous iliac graft. According to histological findings the cyst wall consisted of a single layer of columnar epithelial cells with secretory granules and immunohistochemical examination revealed that the cyst wall was positive for cytokeratin 7. Symptoms improved immediately. Subsequently, the patient was discharged with good performance status. Endodermal cysts are very rare developmental cysts derived from the embryonic endodermal layer. Moreover, these lesions are usually located intradurally in the cervical and upper dorsal spine ventral to the spinal cord. Total removal of the cyst is recommended if it is possible. However, total resection is often difficult due to adhesion of the cyst wall to the neural tissue so invasive resection should be avoided. In such cases, follow-up MRI is necessary in order to exclude recurrence of the remnant lesion.     

Benign hemorrhagic renal cyst: a case report

A case of benign hemorrhagic renal cyst in a 64-year-old man is reported. The patient was admitted to our hospital for further evaluation of left upper abdominal mass. CT scan and ultrasonic sonography showed a left giant renal cystic mass. The characteristic findings were thick and irregular wall and heterogeneous contents of the cystic mass. Selective renal arteriography showed a hypervascular area in a part of the cyst wall and hemorrhagic cyst was suspected by MR imaging. The presence of a malignant tumor in the cyst wall was suspected, and radical nephrectomy was performed. The specimen measured 18 x 12 x 8 cm and weighed 1,170 g. The cyst contained bloody fluid and a hemorrhagic degenerating mass. Pathohistological examination showed no evidence of malignant tumor at any site of the cyst wall.     

True intraspinal neurenteric cyst in the lumbosacral region--case report

A 56-year-old man presented with a very rare true neurenteric cyst in the conus medullaris without evidence of vertebral or visceral anomaly manifesting as a 6-month history of mild low back and bilateral inguinal pain. No motor weakness was found in the bilateral lower extremities. He had also suffered dysesthesia in the bilateral feet for several weeks before admission. Lumbar spine magnetic resonance (MR) imaging demonstrated a cystic intradural extramedullary mass at the L1-2 levels without enhancement after gadolinium injection. MR imaging, computed tomography, and radiography detected no vertebral anomaly. Lumbar laminectomy at the L1-2 levels was performed and the lesion was incompletely removed. Histological examination showed the cystic wall lined with ciliated columnar epithelium. Neurenteric cyst should be considered in the diagnosis of isolated cystic mass lesion at the lumbosacral region even in the absence of vertebral or visceral abnormality.     

Posterior fossa epithelial cyst of ectodermal origin

The case of a large ventral cyst of the posterior fossa of probable ectodermal origin in a 33-year-old patient is presented. Intracranial epithelial cysts are rare, and their histogenesis is a subject of controversy. Previous reports have hypothesized either a neuroepithelial or endodermal origin for the majority of these cysts. This case is unusual because it is the first case, to our knowledge, where melanocytes and melanin have been demonstrated within the cyst wall. These findings suggest an ectodermal origin for this cyst.     

Retro-odontoid cystic mass treated by laminectomy and C1-C2 fixation

Retro-odontoid cysts associated with chronic atlantoaxial subluxation are extremely rare. This article describes a case of retro-odontoid cystic mass associated with chronic atlantoaxial subluxation and its management with posterior C1 and partial C2 laminectomy and C1-C2 pedicle screw fixation without resection of the retro-odontoid cyst. A 64-year-old woman experienced a sudden onset of neck pain, hand and foot paresthesia. Atlantoaxial instability associated with a retro-odontoid cystic mass was found in the imaging. The patient underwent posterior C1 and partial C2 laminectomy and C1-C2 pedicle screws fixation without resection of the retro-odontoid cyst. During the 24 months followup period, the cyst disappeared completely and the patient remained symptom free and returned to independent daily living. These findings suggest that posterior laminectomy and fixation without resection of the retro-odontoid cyst is relatively simple and safe and the results are satisfactory.     

Endodermal cyst ventral to the lower brain stem

A 28-year-old woman presented with a rare case of endodermal cyst located ventral to the lower brain stem manifesting as recurrent aseptic meningitis. Computed tomography and magnetic resonance imaging demonstrated a cystic mass located ventral to the lower brain stem and extending from the prepontine to the upper cervical (C-2) cistern. The lesion was totally removed through a retrosigmoid craniotomy and C1-2 hemilaminectomy. Histological and immunohistochemical examination showed the cyst was derived from the endoderm. The histological diagnosis was endodermal cyst. Early diagnosis and surgical removal are important for patients with these cysts.     

Ventral intradural endodermal cyst in the cervical spine treated with anterior corpectomy--case report

A 14-year-old girl who presented with an endodermal cyst manifesting as severe neck and shoulder pain along with vesicorectal disturbances. Cervical magnetic resonance imaging showed a slightly enhanced intradural cyst at the C6-7 level in the ventral side of the spinal canal, with significant dorsal shortening and thinning of the spinal cord. Anterior corpectomy was chosen because of the dorsal effacement of the spinal cord. The cyst wall was subtotally removed to avoid damage to the normal spinal cord. After cyst removal, the iliac bone and an anterior cervical plate were used for anterior fusion. Postoperatively, her pain subsided without neurological deficits. The histological diagnosis was endodermal cyst. The cyst did not recur during a follow-up period of 18 months. Endodermal cysts are rare congenital lesions of the spine lined by endodermal epithelium. The natural history of this lesion is unclear, and the surgical strategy for the approach route and the extent of removal of the cyst wall remain controversial. We suggest that the anterior approach may allow a safer and more effective surgical route for the treatment of ventrally located endodermal cyst compared to the posterior approach.     

Multiple neurenteric cysts in the posterior fossa and cervical spinal canal--case report

A 46-year-old woman presented with multiple neurenteric cysts in the posterior fossa and spinal canal. Neuroimaging demonstrated neurenteric cysts in the interspace between the left cerebellar hemisphere and vermis, the lateral side of the right cerebellar hemisphere, and the ventral side of the spinal cord at the C-2 and C-4 levels. Total resection of the paravermian cyst and partial removal of the spinal cyst at the C-4 level were performed. Histological examination showed the cyst wall consisted of single or multiple layers of columnar epithelial cells with secretory granules, with mucin secretion verified by periodic acid-Schiff staining. Immunohistochemical staining showed the walls were positive for the cytokeratin, epithelial membrane antigen, and carcinoembryonic antigen, and negative for glial fibrillary acidic protein and S-100 protein. These findings confirmed the endodermal origin. The diagnosis was neurenteric cyst. The paravermian cyst disappeared, but the spinal cyst at the C-4 level recurred 8 months later. Reoperation became necessary 16 months later. The other two cysts also showed enlargement at 6 or 15 months. Total removal of neurenteric cyst is recommended if possible.     

Endodermal cyst of the cerebellopontine angle cistern: case report]

We report a case of a 55-year-old man with endodermal cyst located in the cerebellopontine angle cistern. The patient presented with dizziness. Magnetic resonance imaging (MRI) revealed multilocular cystic lesion at the right cerebellopontine angle. T1-weighted image showed a mass with a low signal intensity, but higher intensity than CSF. Gd-DTPA T1-weighted image showed no enhancement in the mass. Diffusion-weighted image showed a mass with no signal lesion. After successful surgical removal, it was found to be an endodermal cyst. These cysts have usually been found in the spinal canal, and their intracranial occurrence is exceptional. The unusual location of the cyst and its histological features and radiological findings are discussed.     

Posterior fossa epidermoid cysts presenting with unusual radiological appearances--two case reports

Intracranial epidermoid cysts generally appear as hypodense on computed tomography (CT), hypointense on T(1)-weighted magnetic resonance (MR) imaging, and hyperintense on diffusion-weighted MR imaging. We report two cases of posterior fossa epidermoid cysts with unusual radiological features. A 49-year-old male presented with facial dysesthesia and a 12-year-old male presented with diplopia and internuclear ophthalmoplegia. CT of both cases revealed hyperdense lesions. MR imaging showed the first case as hypointense in the posterior part and hyperintense in the anterior part of the tumor on diffusion-weighted imaging, and the second case as hyperintense on diffusion-weighted and T(1)-weighted MR imaging. Surgical exploration revealed that the tumors consisted of creamy materials, instead of the usual semi-solid or flaky texture in epidermoid cysts. Xanthochromic serous fluid was also contained in the superoposterior half of the cyst of the first case. These unusual contents of the cyst may be responsible for the unusual neuroimaging findings. Histological examination showed both cysts were lined with stratified squamous epithelium and contained keratinaceous materials. Therefore, epidermoid cysts can occasionally present with unusual radiological characteristics giving rise to a diagnostic pitfall.     

Pituitary abscess manifesting as meningitis and photophobia associated with Rathke's cleft cyst in a child. Case report

A 12-year-old girl presented with complaints of headache, lethargy, photophobia, and fever. Cerebrospinal fluid examination revealed bacterial meningitis. Magnetic resonance (MR) imaging showed a cystic lesion with peripheral enhancement in the pituitary fossa. The patient underwent transnasal-transsphenoidal surgery (TSS). The diagnosis was pituitary abscess associated with Rathke's cleft cyst. Postoperatively, the patient recovered rapidly. However, recurrence of the pituitary abscess causing meningitis occurred four times and required repeated TSS. She had diabetes insipidus and received hormone replacement. This case requiring repeated emergency surgeries shows that follow-up examinations including MR imaging and pituitary endocrine evaluation are necessary because the rate of recurrence is high in patients with pituitary abscess associated with Rathke's cleft cyst.     

Papillary cystadenocarcinoma of the prostate

A giant cystic formation was found behind the prostate of a 69-year-old man who presented with urinary retention. Ultrasonography, computed tomography scans and magnetic resonance imaging revealed a large cystic intrapelvic mass and biopsy of the cyst wall diagnosed papillary cyst adenocarcinoma. Immunohistochemically, the tumor originated from the prostate.