Non-neoplastic mediastinal cysts.

OBJECTIVE: The non-neoplastic mediastinal cysts (NNMCs) form a group of uncommon benign lesions of a congenital origin. The significant controversy regarding these cysts is whether to manage with observation or surgical resection. The aim of this study is to analyse the utility of thoracic computed axial tomography (CT) in imaging diagnosis of the NNMCs and the results of surgery in these lesions. PATIENTS AND METHODS: Twenty NNMCs underwent surgery between 1980 and 2000. The preoperative study of mediastinal cystic masses includes a complete blood test, chest radiography (CR) and, for the last 15 years, a thoracic CT and/or nuclear magnetic resonance. All the patients underwent surgery in our thoracic surgery department and were reviewed in outpatients at 1 month, 6 months, 1 year and biannually thereafter. The form of manifestation, clinical features, imaging techniques, surgical operation, morbidity, mortality and follow-up are analysed. RESULTS: Ten corresponded to bronchogenic cysts, the most common symptom of which was chest pain. CR showed a mass in the anterior-superior mediastinum in nine cases, and CT (five cases) revealed a cystic tumour in the anterior mediastinum. All were removed surgically, with three patients presenting with mild complications. Seven corresponded to pleuro-pericardial cysts, four being asymptomatic. CR showed a right paracardial mediastinal tumour, which was confirmed by CT (four cases). All were removed surgically, with two patients presenting with mild complications. Three corresponded to enteric cysts. CR showed a tumour in the posterior mediastinum, with CT confirming its cystic nature (two cases). Excision of the cyst was done in all cases, which corresponded to duplication cysts: two oesophageal and one gastric. All the patients are asymptomatic and recurrence-free after a follow-up of 11 +/- 10 years. CONCLUSIONS: NNMCs are benign lesions in which the lesions in which the surgery can be done with a low morbidity and mortality rate, enables us to rule out malignancy and offers a definitive cure. Actually the thoracic CT permit a correct diagnosis pre-surgery in function of the radiologic characterisation and topography.     

Long-term surgical outcome in patients with intracranial hydatid cyst

Summary Background. Cerebral hydatid cysts account for up to 3.6% of all intracranial space-occupying lesions, in endemic countries. The vast majority of patients affected are children. Computed tomography (CT) and magnetic resonance imaging (MRI) have greatly contributed to a more accurate diagnosis of hydatids. However, correct pre-operative diagnosis still remains quite puzzling. Extirpation of the intact cyst is the treatment of choice, resulting in most cases to a complete recovery. Method. In our retrospective study, we have reviewed 76 cases of intra-cranial hydatid disease operated on in our hospital over a 22 year period. Presenting clinical symptoms and signs and the radiological findings on CT and MRI were documented. Albendazole was given preoperatively to patients with giant (>5 cm) or multiple cysts and postoperatively to all patients. The follow-up period ranged from 12 months to 22 years and the outcome was assessed using the Glasgow Outcome Scale (GOS). Findings. Sixty seven (95.7%) of our patients were children. Increased intracranial pressure and papilledema were the predominant findings in this group, whereas focal neurological deficits were most prevalent in adults. CT and MRI revealed round cystic lesions, isodense and iso-intense respectively to cerebrospinal fluid (CSF), with no rim enhancement or perifocal edema. Multiple cysts were identified in 3 cases. Extirpation of the cyst without rupture was accomplished in 56 patients (73.7%). Recurrences occurred in 19 patients (25%). 4 patients (5.3%) died within 6 months after surgery; 3 of these patients had multiple cysts and one died shortly after the operation due to anaphylactic shock following intra-operative rupture of the cyst. Conclusion. Long-term follow-up confirms that intracranial hydatid cysts should always be surgically removed without rupture; the outcome remains excellent in these cases. Correct preoperative diagnosis is vital for the successful outcome of surgery. A high index of suspicion is therefore required in endemic areas despite the availability of advanced neuro-imaging. Medical treatment with albendazole seems to be beneficial both pre- and post-operatively. Newer diagnostic methodologies, such as MR spectroscopy and MR diffusion weighted imaging, might lend themselves to the diagnosis of intracranial hydatid cysts.     

Clinicopathological and endocrinological study of Rathke's cleft cyst manifesting as hyponatremia

Rathke's cleft cyst becomes symptomatic in a few cases. Increasing experience has identified previously unrecognized clinical effects including pituitary dysfunction. This study retrospectively investigated eight patients with Rathke's cleft cyst manifesting as hyponatremia and treated surgically with histological confirmation to clarify the mechanism of hyponatremia. All patients suffered from physical symptoms caused by the hyponatremia. All patients underwent magnetic resonance (MR) imaging and screening of pituitary hormones in addition to cortisol and thyroid hormones. All patients had cysts of more than 10 mm in diameter and MR imaging frequently showed irregularly thickened cyst wall. Histological examination disclosed various phases of inflammation and significant fibrosis. Endocrinological examination showed low concentrations of both serum cortisol in all eight patients and urinary cortisol in six of six patients examined. The major cause of hyponatremia was hypocortisolemia, induced by damage to the anterior pituitary gland.     

Evaluation of complicated renal cyst: a comparison of CT and MR imaging]

We report 12 cases of renal cystic lesions that could not be diagnosed preoperatively. Sonography, computed tomography (CT), magnetic resonance (MR) imaging, and angiography were performed in all cases. Angiography was not helpful in evaluating cystic lesions, because all cystic lesions were hypovascular or avascular within the cystic mass. CT was useful in depicting the fine structural abnormalities, and especially bolus-contrast CT study was useful in the differentiation of cystic renal cell carcinoma from simple renal cyst. However, there were 5 false positive cases. MR imaging is superior to CT in distinguishing a hemorrhagic cyst or multiloculated cystic mass. In conclusion, CT is currently the primary imaging modality for evaluating complicated renal cysts, and surgical exploration is warranted for the undiagnosed cystic lesion by CT. However, MR imaging also has an important role in detecting the benign complicated cyst. Therefore if complicated cyst is thought to be benign by MR imaging, parenchyma-sparing surgery should be considered preoperatively.     

Hyperdense intracranial epidermoid cysts: a study of 15 cases

Summary Background. Although intracranial epidermoid cysts generally appear as hypodense lesions on CT scans, occasionally, they may appear hyperdense, making diagnosis difficult. The aim was to study clinical features and possible pathogenesis of hyperdense intracranial epidermoid cysts (HIECs). Methods. Fifteen patients with HIECs were surgically treated in our department during a 21-year period (1985 up to 2005). We reviewed each patient’s clinical records, radiological findings, operative reports, and pathological examinations, along with a review of the literature. Findings. The incidence of HIECs in our series was approximately 3.02%, with female predominance. The average age was 32 years and the average duration of complaints was nine months. The most common location was the parasellar area (6 cases), followed by cerebellum (4 cases), clival region (3 cases), cerebello-pontine angle (1 case) and lateral ventricle (1 case). Gross-total excision of the tumor was achieved in ten patients (66.7%). Four (26.7%) patients underwent subtotal resection; and one (6.6%) patient underwent partial resection. Aseptic meningitis that occurred postoperatively in two cases was controlled by lumbar drainage. Conclusions. Recurrent leakage of the irritating cyst contents and subsequent chemical inflammatory response may be responsible for the high-density on CT scans and the cystic nature. A correct histological diagnosis is important because, in contrast to typical ECs and other lesions, HIECs are more prone to spread intra-operatively and result in severe aseptic meningitis.     

Stereotactic radiosurgery to treat presumed Rathke's cleft cysts

Abstract Objective. Stereotactic radiosurgery (SRS) has been developed as a clinical treatment method for certain brain tumours that does not need craniotomy. As a more accurate radiation technique, SRS can deliver a relatively large dose of stereotactic radiation to a conformal target with less normal brain tissue irradiated in a single treatment. The aim of this study is to evaluate the therapeutic effects of SRS for Rathke's cleft cysts (RCCs). Methods. SRS was performed using a rotating gamma ray unit in seven selected patients with symptomatic RCCs diagnosed upon typical MR imaging combined with clinical manifestation. The patients included one male and six females with an age range from 25 to 63 years (mean 43.4 years). Five patients presented with headache, three with menstrual disorder or infertility and one with vision impairment. No other endocrine dysfunction was observed. SRS was performed in the patients with a central dose varied from 22.6 to 40 Gy (mean 32.5 Gy) and a peripheral dose from 9 to 20 Gy (mean 13.4 Gy). Results. The patients were followed up for 11-105 months (mean 38.6 months) after SRS. All symptoms that presented before treatment were relieved within 3-6 months post-SRS and no endocrine dysfunction was developed during the follow-up period. MR imaging demonstrated that the RCCs were completely disappeared in five cases and significantly shrunken in the other two cases. No recurrence was observed in any cases during the follow-up. Conclusion. This study demonstrates that SRS can treat RCCs effectively without evident side effects.     

Systematic review of the natural history of vestibular schwannoma

OBJECT: Magnetic resonance (MR) imaging now permits diagnosis of increasing numbers of small, minimally symptomatic vestibular schwannomas (VSs). Because VS growth patterns over time are very important in refining treatment strategies, these matters were systematically reviewed. METHODS: An extensive MEDLINE search was performed to cull studies on VS growth according to sequential imaging. The percentages of growing and regressing tumors and lesions requiring treatment during follow-up periods were calculated. Factors associated with differences among studies were identified. Twenty-six studies including 1340 patients met all inclusion criteria. The overall frequency of VS growth during a mean follow-up period of 38 months was 46% (95% confidence interval [CI] 43-48%) and that of regression was 8% (95% CI 6-10%). The mean annual tumor growth rate was 1.2 mm/year. Furthermore, the percentage of cases requiring treatment during follow up was 18% (95% CI 16-21%). According to results of a sensitivity analysis, evaluation by serial MR imaging (39%, 95% CI 35-43%) and a prospective study design (29%, 95% CI 21-37%) were associated with less frequent reported tumor growth. CONCLUSIONS: Although their applicability may be limited to relatively elderly patients with small tumors, data revealing a limited frequency of VS enlargement and an infrequent necessity for eventual therapy should assist decision-making in the treatment of small VSs causing minimal symptoms.     

Trigeminal neuralgia caused by microarteriovenous malformations of the trigeminal nerve root entry zone: symptomatic relief following complete excision of the lesion with nerve root preservation

OBJECT: Within a series of 341 consecutive patients who underwent posterior fossa surgery for trigeminal neuralgia (TN), in five the cause was found to be a microarteriovenous malformation (micro-AVM) located in the region of the trigeminal nerve root entry zone (REZ). The surgical management and clinical outcomes of these cases are presented. METHODS: Patients were identified from a prospectively collected database of all cases of TN treated at one institution between 1980 and 2000. Presentation was clinically indistinguishable from TN caused by vascular compression. Preoperative imaging, including computerized tomography scanning (two cases) and magnetic resonance (MR) imaging and MR angiography (three cases), failed to demonstrate an AVM except for one case in which multiple abnormal vessels were identified in the trigeminal REZ on an MR image obtained using a 1.5-tesla magnet. All patients underwent a standard retromastoid craniotomy. In all cases a small AVM embedded in the trigeminal REZ was identified and completely excised, with preservation of the trigeminal nerve. All patients experienced immediate relief of pain following surgery. Postoperatively, in one patient a small pontine hematoma developed, resulting in permanent trigeminal nerve anesthesia in the V2 and V3 divisions. All patients were free from pain at a mean follow-up period of 30 months. CONCLUSIONS: These rare lesions are usually angiographically occult, but may sometimes be identifiable on high-resolution MR images. Total microsurgical resection with nerve preservation is possible, although operative complications are relatively common, reflecting the intimate association between these lesions and the pons. Complete resection is advised not only for symptom relief, but also to eliminate the theoretical risk of pontine hemorrhage.     

Rathke's cleft cyst presenting as sphenoid sinusitis.

Rathke's cleft cysts are developmental abnormalities of the craniopharyngeal duct composed of retained stratified ciliated cuboidal cells of the respiratory type. Incidentally found in the pars intermedia in 13% to 33% of routine autopsies, they are discovered in growing numbers on CT and MRI scans. From 1991 to 1999, 9 cases of Rathke's cleft cysts were encountered by the senior authors, 4 of which were treated surgically (3 by using a transsphenoidal approach and one by using a transcranial subfrontal approach). Of the 3 patients treated with a transsphenoidal approach, 2 presented with symptoms mimicking sphenoid sinusitis and were initially referred for otolaryngologic evaluation. The clinical, pathologic, and radiologic features, as well as management and follow-up of those 2 patients, are reviewed. There has been only one previous case report of Rathke's cleft cysts presenting as sinusitis. Nevertheless, the otolaryngologist should be aware of this condition because it may present with other significant symptomatic extracranial extensions.     

Colloid cysts: experience with the management of 84 cases since the introduction of computed tomography

A retrospective review of colloid cysts diagnosed from 1974 to 1986 emphasizes the presenting symptoms of these lesions, their surgical management, and the contribution of modern imaging techniques to their diagnosis and therapy. In this 12-year period, 84 patients (45 men and 39 women) had a colloid cyst diagnosed. The patients' mean age was 46 years (range, 7-82 years). Surgery was performed in 55 patients, 7 of whom had undergone prior surgery elsewhere. The surgical approaches used were transfrontal-transventricular, transcallosal, computer-assisted stereotactic aspiration and resection by stereotactic craniotomy, and shunting of cerebrospinal fluid without removal of the lesion. There was no operative mortality, but complications occurred in 15 patients (27%). Preoperative imaging showed hydrocephalus in 93% of the patients: severe in 43%, moderate in 36%, and mild in 14%. In the surgically treated group, the most common presenting symptoms were headache, change in mental status, ataxia, nausea and vomiting, visual disturbance, emotional lability/inappropriate affect, depersonalization, and hypersomnolence. Twenty-four patients for whom surgery was not recommended are being followed up closely. Most of these patients had normal ventricles. The symptoms in this group included headache, anxiety/nervousness, ataxia, memory impairment, visual disturbance, and seizures. Five autopsy cases of patients with colloid cysts were available during this period and were reviewed. Direct removal of colloid cysts can be accomplished with low morbidity and mortality, avoiding the frequent revisions and complications related to shunt procedures. There is a subgroup of colloid cysts that can be operated upon electively or followed up closely with serial imaging studies.     

Transsphenoidal management of Rathke's cleft cysts a clinicopathological review of 10 cases

We report detailed data on 10 patients who underwent transsphenoidal microsurgical management of histopathologically confirmed Rathke's cleft cysts. Preoperatively, pituitary dysfunction was present in 90%, headaches in 80%, hyperprolactinemia in 70%, and visual interference in 40%. Computed tomography and magnetic resonance imaging had 90% and 100% sensitivity, respectively, in disclosing the lesion. The mean follow-up duration was 22 months. There was no mortality. The only morbidity was sustained diabetes insipidus in one case. Resolution or improvement in preoperative dysfunction occurred in the majority of patients: headaches in 100%, visual deficits in 75%, normalization of hyperprolactinemia in 83%, and reversal of panhypopituitarism in 33%. We conclude that Rathke's cleft cysts can be managed safely and effectively with transsphenoidal drainage and partial excision of the wall.     

Computed tomography-guided localization of breast lesions

Abstract:  Magnetic resonance (MR) imaging and computed tomography (CT) of the breast allow the detection of breast lesions occult on physical examination, mammography and ultrasound. We report our experience to localize such lesions under CT-guidance. 30 patients underwent 30 CT-guided preoperative localizations of breast lesions using a sequential technique or a continuous imaging. All these lesions were initially detected by MR ( n  = 11) and/or CT ( n  = 19) and were occult for all the other techniques. In eight patients with a superficial and/or internal lesion, a skin location using a painting pen was performed. In the 23 other cases, the extremity of a hookwire was placed into the lesion or within 5 mm surrounding the target. All the lesions were localized with success under CT-guidance. The pathological analysis of the surgical specimens concluded in 11 breast cancers, four lesions of uncertain malignancy potential and 15 benign lesions. The size of these lesions ranged from 4 to 28 mm (mean: 10 mm). No significant complication related to the procedure was observed. Localization under CT guidance is a safe and effective technique to guide the surgical biopsy of breast lesions that can be seen solely on MR or CT.     

骨嗜酸性肉芽肿的影像诊断

目的探讨骨嗜酸性肉芽肿的影像表现特点。方法回顾性分析10例经手术病理证实的骨嗜酸性肉芽肿的X线、CT及MRI表现。10例患儿均接受CT检查,3例同时接受患部X线平片检查,5例同时接受患部MR检查,其中4例接受MR增强扫描。结果病变单发8例,多发2例。累及颅面骨4例,长骨3例（肱骨1例,胫骨1例,股骨1例）,髂骨2例,锁骨2例,椎体1例,肩胛骨1例。不同部位病变影像学表现有差异,主要表现为骨质破坏,形成软组织肿块,边缘清楚、无硬化。结论综合影像学检查能显示骨嗜酸性肉芽肿的病变形态、范围、特点,有助于诊断及鉴别诊断。     

Surgical management of facet cysts in the thoracic spine: Radiological manifestations and results of fenestration

BackgroundFacet cysts in the thoracic spine are a rare cause of thoracic myelopathy. We aimed to investigate the clinical/radiological features and surgical results of these lesions.MethodsNine thoracic facet cysts in eight patients (seven men, one woman) were diagnosed based on magnetic resonance imaging (MRI) and computed tomography (CT) with facet arthrography findings and surgically treated. The mean patient age was 71 (59–83) years. The cysts were distributed as follows: one each at T8–9 and T9–10, two each at T1–2 and T11–12, and three at T10–11. The mean follow-up period was 1.8 (1–5) years. Clinical and radiological features were retrospectively investigated, and surgical outcomes were evaluated according to modified Japanese Orthopaedic Association (JOA) scores for thoracic myelopathy (full score: 11).ResultsNeurological examination revealed progressive thoracic transverse myelopathy in all patients with a mean disease duration of 1.2 months (2 weeks–2 months). MRI revealed a total of nine cysts across the eight patients: four in the median region and five in the paramedian portion of the spinal canal. CT revealed degeneration in all involved facet joints. All the cysts were in communication with the neighboring facet joint confirmed by CT facet arthrography. All patients underwent bilateral fenestration, and the cysts were resected with the ligamentum flavum. The mean preoperative and postoperative modified JOA scores were 4.5 and 8.8, respectively. The mean recovery rate was 67.5%. Differences in the degree of local kyphosis were 2° or less between before and after surgery. On histopathology, synovial lining cells were not noted in any case.ConclusionsDecompression surgery is recommended for treating progressive myelopathy in patients with cystic lesions. Our study suggests that thoracic facet cyst resection with satisfactory surgical outcomes would be possible through fenestration.     

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.     

Nontraumatic intradiploic arachnoid cysts--report of five cases.

Five cases of nontraumatic intradiploic arachnoid cysts in elderly patients are reported. All cysts were located in the occipital bone and appeared as well-demarcated radiolucent lesions. The cysts were multiple in three cases. Presenting symptoms included headache or dizziness, but most lesions were asymptomatic and found incidentally. In the most recent three cases, magnetic resonance (MR) imaging revealed intradiploic cysts containing cerebrospinal fluid (CSF) with cerebellar herniation. Operation found the cysts filled with CSF and dural defects through which cerebellar tissue was herniating. In two patients, CSF leakage from the outer table occurred. Intradiploic arachnoid cyst seems to be congenital in origin but commonly found in the elderly. MR imaging is the most useful diagnostic method for differential diagnosis from other osteolytic skull lesions.     

Posterior fossa arachnoid cysts.

Arachnoid cysts of the posterior fossa are rare lesions that are considered to be mostly congenital in origin. In this article, we retrospectively review 12 patients who underwent surgical treatment for their symptomatic posterior fossa arachnoid cysts. The most common presenting symptoms were gait disturbances and headache. The diagnosis was established on computed tomography or magnetic resonance imaging. Surgery consisted of cyst wall excision with fenestration in nine cases and shunting procedures in three cases. In all cases except one who-died, the postsurgical follow-up neuroradiological investigations showed that the cysts had decreased in size, the cerebellum had re-expanded, and if there was preoperative hydrocephalus, the ventricular size was decreased. The follow-up period ranged from 1 to 11 years. All surviving cases are free of symptoms and no arachnoid cysts recurred. The classification, pathophysiology, differential diagnosis and surgical treatment of infratentorial arachnoid cysts are discussed and the relevant literature is reviewed.     

Splenic abscess. An old disease with new interest

BACKGROUND/AIMS: To study the demographics, signs and symptoms, causes, risk factors, imaging findings, bacteriologic profile, treatment and outcome of patients with splenic abscess. METHOD: The medical records of 17 patients with splenic abscess at two tertiary-care hospitals between 1989 and 1997 were retrospectively reviewed. The demographic data, physical and radiological findings, treatment, bacteriology reports and outcome of treatment were reviewed. RESULTS: The mean age of patients was 43 years (range 7-79 years). Fever and abdominal pain were the most prominent signs. Seven patients were immunocompromised, three had abscessed hydatic cysts, two were drug users and three suffered from splenic trauma, infarction, and endocarditis, respectively. No predisposing factor was identified in 2 patients. In all cases, CT demonstrated the splenic lesion(s). Staphylococcus species and Bacteriodes were the most common microbes, identified in the blood and abscess cultures. Thirteen patients underwent splenectomy, two medical therapy and two no therapy with respective survival rates of 92, 100 and 0%. CONCLUSION: Splenic abscess is a rare surgical entity encountered mostly in immunocompromised patients. CT scan is the gold standard for the definite diagnosis. Splenectomy is the treatment of choice, while medical therapy should be reserved for unusual pathogens provided that an effective antimicrobial agent is available.     

Management of Rathke's cleft cysts

BACKGROUND: Incidental diagnosis of Rathke's cleft cysts (RCCs) has increased due to the improvements in imaging techniques; however, symptomatic cases are rare and accurate preoperative diagnosis can be difficult. METHODS: Files and magnetic resonance imaging (MRI) of 10 surgically treated patients with RCC and 8 conservatively managed cases with a suspected diagnosis were reviewed retrospectively. Clinical, radiological, and histological features as well as intraoperative findings were scrutinized. RESULTS: In the surgical group, headache was present in 4 patients, hormonal abnormality in 4, visual deficits in 3, and otolaryngological symptoms in 2. Two of the nonsurgical cases had hyperprolactinemia, and the remaining were asymptomatic. The cyst had suprasellar extension (SSE) in 9 patients and was entirely suprasellar in 1 in the surgical group. It was purely intrasellar in 6 nonsurgical cases and had SSE in 2. The cyst content showed hyperintense MRI signal in the majority of T1 and T2 images in both groups. Transsphenoidal surgery was performed in 8 and transcranial surgery in 2 patients. Squamous metaplasia and inflammation was present in 3 cases each. Initial hormonal deficiencies did not improve postoperatively and new deficits were observed in 2 cases. There was no recurrence with an average follow-up of 32 months. CONCLUSIONS: Rathke's cleft cysts is a rare pathology with a wide spectrum of clinical and radiological features. Reactive inflammation of the normal pituitary gland may have a role in the pathogenesis of hormonal deficiency, in addition to compression. Preoperative recognition of the anteriorly displaced normal residual gland may be important in avoiding postoperative hormonal deficiency after transsphenoidal approach.