Foreign body granuloma mimicking intracranial meningioma: case report and review of the literature

Impact Assessment of Pituitary Adenylate Cyclase Activating Polypeptide (PACAP) and Hemostatic Sponge on Vascular Anastomosis Regeneration in Rats

The proper regeneration of vessel anastomoses in microvascular surgery is crucial for surgical safety. Pituitary adenylate cyclase-activating polypeptide (PACAP) can aid healing by decreasing inflammation, apoptosis and oxidative stress. In addition to hematological and hemorheological tests, we examined the biomechanical and histological features of vascular anastomoses with or without PACAP addition and/or using a hemostatic sponge (HS). End-to-end anastomoses were established on the right femoral arteries of rats. On the 21st postoperative day, femoral arteries were surgically removed for evaluation of tensile strength and for histological and molecular biological examination. Effects of PACAP were also investigated in tissue culture in vitro to avoid the effects of PACAP degrading enzymes. Surgical trauma and PACAP absorption altered laboratory parameters; most notably, the erythrocyte deformability decreased. Arterial wall thickness showed a reduction in the presence of HS, which was compensated by PACAP in both the tunica media and adventitia in vivo. The administration of PACAP elevated these parameters in vitro. In conclusion, the application of the neuropeptide augmented elastin expression while HS reduced it, but no significant alterations were detected in collagen type I expression. Elasticity and tensile strength increased in the PACAP group, while it decreased in the HS decreased. Their combined use was beneficial for vascular regeneration.

Intracranial gossypiboma 9 years after intracranial pressure bolt insertion: illustrative case

BACKGROUND

Resorbable hemostatic agents left behind postoperatively occasionally result in granulomatous space-occupying lesions known as “gossypibomas.” The authors report a case of an intracranial gossypiboma, which is exceedingly rare and frequently radiologically indistinguishable from other lesions.

OBSERVATIONS

A 35-year-old woman presented with a generalized tonic-clonic seizure and subsequent left-sided hemiparesis. Magnetic resonance imaging showed an enhancing lobulated lesion subjacent to a right frontal burr hole, surrounded by vasogenic edema with mass effect and midline shift. Nine years earlier, she had had a triple bolt inserted to monitor intracranial pressure after sustaining a traumatic brain injury. Surgicel was used to control bleeding during insertion. Colocation of the lesion with the position of triple bolt 9 years earlier raised suspicion for gossypiboma. However, the minor nature of the surgery and the length of time since surgery to presentation placed this case well outside the range of cases reported in the literature. The lesion was resected en bloc with no recurrence 18 months later. Histological examination revealed the presence of foreign material. However, given its minute size, confirming its nature was not possible.

Lessons

The authors show that gossypibomas can occur following a relatively minor procedure and remain clinically and radiologically silent for much longer than previously reported.

Bone Fragment Granuloma Mimicking a Brain Tumor Following Placement of an Intracranial Pressure Monitoring System

The placement of intracranial pressure (ICP) monitoring system requires drilling an orifice in the skull. Bone fragments can accidentally be inserted into the brain parenchyma while introducing the ICP monitoring system during the procedure. An intracranial granuloma can be subsequently formed if a non-specific reaction is induced and maintained by the inserted bone fragment in the brain parenchyma. These intracranial granulomas may eventually be confused with brain masses on follow-up imaging studies. We present the case of a 65-year-old male who underwent cranial surgery secondary to a severe traumatic brain injury (TBI). An intracranial bolt was initially placed contralaterally to measure the ICP. Eleven years later, a granuloma from a retained bone fragment secondary to the intracranial bolt placement was suspected. The clinical course, radiological investigations, and differential diagnosis are presented.

Use of Oxidized Regenerated Cellulose as a Hemostatic Agent in Neurosurgery: Appraisals and Recommendations to Prevent Postoperative Complications and Facilitate Follow-Up

Neurosurgical hemostasis can be performed with bipolar coagulation and with the support of several dedicated biomaterials including oxidized regenerated cellulose (ORC; e.g., Surgicel®, Johnson & Johnson, New Brunswick, NJ, USA). Oxidized regenerated cellulose is a sterile absorbable fibrous biomaterial that has become a major local hemostatic agent thanks to its ease of use, favorable biocompatibility and bioabsorption characteristics. However, some postoperative issues associated with its use, such as allergic reaction, seroma, foreign-body reaction with compressive neuropathies and misdiagnosis during follow-up, have been reported. These complications could compromise clinical outcomes with a negative impact on patient quality of life and sometimes require risky major surgical procedures. An understanding of the specific properties of ORC combined with adequate surgical expertise and compliance with some basic rules are needed to optimize clinical outcomes and minimize postoperative issues.

MRI findings for diagnosis of postoperative foreign body granulomas versus recurrent tumours in patients of brain tumour surgery

AIM

To evaluate the postoperative magnetic resonance imaging (MRI) findings of intracranial foreign body granulomas (FBGs) and true recurrent tumours (RTs) and thus lead to a basis for management decision-making.

MATERIALS AND METHODS

Twenty-two patients with previous brain tumour surgery were diagnosed clinically with RT and underwent surgery. Re-operative pathology revealed FBG in eight patients and RT in 14 patients. MRI findings before the initial operation were compared to those before the re-operation.

RESULTS

Features of FBGs versus RTs on MRI were as follows: (1) mean lesion size: 1.3 ± 0.7 (0.5-2.6) versus 3.2 ± 1.7 (1.1-6.3) cm (p=0.001, odds ratio [OR] = 4.18); (2) hypointensity on T2-weighted imaging (WI): 6/8 (75%) versus 0/14 (0%; p<0.001, OR=75.4); (3) non-restricted diffusion on diffusion-WI (DWI): 6/8 (75%) versus 2/14 (14.3%; p=0.008, OR=18); and (4) "ring and bubble" appearance on contrast-enhanced T1WI: 7/8 (87.5%) versus 2/14 (14.3%; p=0.001, OR=42). In comparison with their original tumours, the FBGs in the FBG group showed significantly lower T2 signal intensity, lower signal on DWI, and more cases of non-restricted diffusion on DWI (p=0.04, 0.04, 0.04, respectively).

CONCLUSION

On brain MRI, FBGs can be differentiated from RTs by their relatively smaller size, hypointensity on T2WI, lack of restricted diffusion on DWI, and "ring and bubble" appearance on contrast-enhanced T1WI. Comparing the MRI findings of the focal lesion in the tumour bed with those of the original tumour is suggested to enhance diagnostic confidence.

Postoperative Textiloma Mimicking Intracranial Rebleeding in a Patient with Spontaneous Hemorrhage: Case Report and Review of the Literature

During craniotomy, hemostatic materials such as oxidized cellulose and cotton pads, commonly used to control bleeding, may cause a granulomatous reaction that may produce space-occupying mass lesions termed textiloma (or gossypiboma). We present a 46-year-old female who underwent a right frontotemporal craniotomy and surgical removal of intraparenchymal cerebral hemorrhage, and who developed a textiloma during the postoperative period causing seizures. Granulomatous reactions due to hemostatic agents have been reported experimentally, as well as after cranial and spinal operations. We emphasize that although it is rare, an adverse reaction such as a postoperative textiloma due to hemostatic material and subsequent granuloma formation can result in a false image of rebleeding, tumor recurrence, radiation necrosis, or postoperative abscess, depending on the particular clinical history of each patient.

Infiltration of Benign Meningioma into Sagittal Sinus and Subsequent Metastasis to Lung: Case Report and Literature Review

BACKGROUND

Meningioma is an intracranial tumor frequently encountered in the neurosurgical setting. Extracranial disease is a rare occurrence, with a reported incidence in 0.1% of cases. Metastasis is associated with previous craniotomy, venous sinus invasion, local recurrence, and World Health Organization (WHO) grade III tumor. Metastasis of a benign, grade I meningioma is extraordinarily rare.

CASE DESCRIPTION

We report a case of a 41-year-old with a WHO grade I intracranial meningioma that had invaded and occluded the superior sagittal sinus. Chest computed tomography (CT) scan revealed pulmonary nodules, which were biopsied and confirmed benign meningioma. The metastatic meningiomas were found before resection of the primary tumor, suggesting direct seeding through the venous system versus iatrogenic seeding. Thirteen years later, an additional lung mass was found incidentally on abdominal CT scan for workup of a sarcoidosis. Biopsy and subsequent resection confirmed benign meningioma. A retrospective review of earlier chest CT scans revealed a small lesion that corresponded to the larger lesion found 13 years later.

CONCLUSIONS

This a rare case of a WHO grade I meningioma involving the sagittal sinus with direct seeding of the pulmonary vascular bed leading to multiple meningioma metastases. The report highlights an increased risk of distant metastases for a benign meningioma with invasion of dural sinuses.

Intracranial foreign material granulomas after cranial surgery

BACKGROUND

Various synthetic materials are used in neurosurgery and left in place intentionally during surgery for several purposes such as hemostasis, dural closure, or cranioplasty. Although leaving such substances in surgical sites is considered safe, in general, foreign body granuloma may occur months or years after intracranial surgery. Thus, far relatively little is known about treatment and outcome of such lesions.

METHODS

A systematic review of 3466 histopathological examinations after cranial surgeries achieved over a 13-year period was performed. After excluding patients with Teflon granulomas or infection, a total of 12 patients with foreign body granulomas induced by synthetic material used in a prior surgery were identified. Patient records, imaging studies, and histopathological data were analyzed. Furthermore, postoperative outcome was assessed.

RESULTS

Mean age at the second surgery was 51 years (range, 11-68 years). The median time between the primary and the secondary surgery was 13 months (range, 1-545 months). Eight patients (75%) presented with signs and symptoms related to the foreign body granulomas. Total resection of the foreign body granulomas was performed in all patients. The granulomas were induced by oxidized cellulose polymer (n = 6), suture material (n = 3), Gelfoam (n = 1), methylmethacrylate (n = 1), and bone wax (n = 1). The mean postoperative follow-up time was 54 months (range 1-137 months). There was symptomatic improvement in all instances. Imaging studies did not demonstrate any recurrence.

CONCLUSION

Despite its rarity, foreign body granuloma should be taken into consideration in the differential diagnosis of intracranial mass lesions especially in cases of suspected tumor recurrence after prior surgery. The pathogenesis of foreign body granuloma still needs further clarification. Our study demonstrates that they have good prognosis after surgical removal.

Foreign Body Granuloma After Cranial Surgery: A Systematic Review of Reported Cases

BACKGROUND

In cranial surgery, different foreign body (FB) materials are used and may be left intentionally or unintentionally in the surgical field after closure, inducing a foreign body granuloma (FBG). This is a rare complication in neurosurgery, but it may be a diagnostic dilemma, with sometimes medicolegal implications.

METHODS

We performed a systematic review of the English literature between 1965 and 2018 and found a total of 77 articles concerning 100 cases of FBG caused by retained material located within the cranium or surrounding soft tissues.

RESULTS

There were 60 females and 40 males, with ages ranging from 1 to 77 years. Most initial diagnoses were cranial/intracranial tumors, trigeminal neuralgia, hemifacial spasm, intracranial aneurysm, hydrocephalus, head injury, infectious disease, and nontraumatic intracerebral hematoma. The interval from the causative surgical operation to presentation of the FBG ranged from 2 weeks to 20 years. Various radiologic modalities were used and histologic study confirmed the presence of FBG in all patients. Intentional FB was used and left in 77 patients, and unintentional FB was found postoperatively in 23 patients. Associated infection was found in 13 patients. Complete recovery was seen in 47.6% of patients with sufficient data.

CONCLUSIONS

Despite being unusual, a retained FBG should be considered in the differential diagnosis of any patient after cranial surgery. A history of surgery, clinical symptoms, physical examination findings, laboratory results, and the use of appropriate neuroimaging explorations may provide a correct preoperative diagnosis. In addition, unintentionally retained FBs are preventable errors in the operating room.

[Granulomatous inflammation in the bed of resected cerebral cavernoma in a child, caused by a hemostatic agent]

OBJECTIVE

The study presents a clinical observation of foreign body granuloma, which is rare productive inflammation, developed on treatment with a hemostatic material upon removal of cerebral cavernoma.

MATERIAL AND METHODS

A 4-year-old boy operated on for left parietal lobe cavernoma was diagnosed with a mass lesion during a follow-up MRI examination 4 months after surgery. The patient was re-operated in connection with suspected abscess formation. The pathological tissue was subjected to the histological and immunohistochemical examination.

RESULTS

Inflammation was accompanied by the formation of foreign body granulomas, and, in some areas, had immune nature with signs of focal destructive vasculitis, delayed maturation of the granulation tissue, and disturbance of the current organization and encapsulation processes. It is worth noting that granulomatous inflammation around a hemostatic material in the brain has no specific features during introscopy and mimics an abscess or tumor recurrence.

CONCLUSION

The use of hemostatic materials upon resection of cerebral cavernous malformations may cause formation of granuloma mimicking disease relapse or abscess in the long term period. To prevent granulomatous inflammation, removal of a hemostatic material, if possible, from the surgical field is recommended when reliable hemostasis is achieved.

Postoperative aseptic intracranial granuloma: the possible influence of fluid hemostatics

Background. Numerous reports have demonstrated how postoperative intracranial granulomas can often mimic neoplasm clinically, radiologically, and even macroscopically. Herein we present an unusual case of postsurgical intracranial aseptic granuloma secondary to a chronic inflammatory reaction without any identifiable retained foreign body. Case Description. A 71-year-old patient started complaining of severe headache seven months after surgical excision of WHO Grade I right frontal falx meningioma. CT and MRI scans disclosed a contrast-enhanced lesion with diffuse mass effect in the previous surgical site. The lesion was resected; intraoperative finding and histological specimens led to the diagnosis of postoperative granuloma, likely expression of a glial reaction to the fluid absorbable hemostatics applied in the surgical site after meningioma excision. The possible granuloma-inducing materials and the timing of granuloma formation are discussed. Conclusion. A comprehensive analysis of clinical and neuroradiological data, as well as results of blood tests including positive and negative acute phase proteins, is mandatory to raise the suspicion of postoperative granuloma. The treatment options should be evaluated on a case-by-case basis, with a conservative attitude being the one of choice only for patients without progressive neurological deficit. Alternatively, aggressive surgical treatment and histopathological examination should be advocated.

Maxillary sinus textiloma: a case report

INTRODUCTION

Textilomas have been reported in many locations. We report the first case of textiloma located in the maxillary sinus that mimicked a sinus cyst recurrence on computed tomography images.

CASE PRESENTATION

A 60-year-old Caucasian man was referred for persistent infection of the right maxillary sinus. A maxillary sinus benign cyst had been removed three months before. Computed tomography showed a sinus opacity evoking a cyst recurrence. A new operation was planned to remove the cyst by a Caldwell-Luc approach. After excision of very thick fibrous tissue, a compress was discovered in the maxillary sinus. The patient did not present with any sinus infection after the operation.

CONCLUSION

The surgeon should always take into account the possibility of textilomas in a patient with a history of sinus surgery.

Postoperative hemicerebellar inflammation mimicking recurrent tumor after resection of a medulloblastoma. Case report

The authors present the case of a 4-year-old boy in whom a medulloblastoma in the left cerebellar hemisphere was successfully resected with no signs of residual tumor on the postoperative magnetic resonance (MR) images. A second MR imaging study performed 1 month after surgery demonstrated an extensive, contrast-enhancing lesion in the left cerebellar hemisphere, which simulated massive recurrent tumor, and repeated surgery was considered. A third postoperative MR imaging study, performed for evaluation of the craniospinal axis 10 days after the second postoperative study, still showed some contrast enhancement in the left cerebellar hemisphere, but the lesion had almost disappeared. Postoperative hemicerebellar inflammation seemed to be the most likely explanation. This case illustrates that early postoperative inflammation can mimic recurrent tumor on MR images obtained after resection of a medulloblastoma and caution should be taken in interpreting such images. Clinical history, neurological examination, laboratory findings, and repeated MR imaging studies can be helpful in evaluating the patient accurately.

Radiculopathy due to microfibrillar collagen hemostat mimicking recurrence of disc herniation

Microfibrillar collagen hemostat (Avitene) is an absorbable topical hemostatic agent prepared from purified bovine corium collagen. A 65-year-old woman presented with left buttock and lower extremity radicular pain. The patient underwent a disc excision in which Avitene was used to control venous bleeding from the epidural space. Leg pain decreased postoperatively, but she developed radicular pain when she started walking 3 days after the operation. Magnetic resonance imaging (MRI) performed post-operatively showed there was a mass lesion located between the dural sac and L5 nerve root. The lesion exhibited high signal intensity on T1-weighted images and higher signal intensity at the rim of the mass on T2-weighted images. A second operation performed 10 days later revealed that the nerve root was adherent to an extradural granulomatous mass associated with Avitene. Macroscopically, the resected mass was found to be composed mainly of microfibrillar collagen hemostat materials. Hemostat agents may produce a clinically symptomatic, radiologically apparent mass lesion. When considering a mass lesion arising after spine surgery, the differential diagnosis should include foreign body granuloma along with recurrent disc herniation and peridural scar formation.

Lintene granuloma following microvascular decompression mimicking a cerebellopontine angle tumour

We describe a case of foreign body granuloma caused by lintene (cotton gauze), placed during microvascular decompression of the fifth nerve for trigeminal neuralgia. At presentation, the clinical and radiological findings were suggestive of a tumor. This is only the second case in the literature of a foreign body granuloma occurring owing to the placement of a lintene pledget during microvascular decompression.

Unrecognized Intracerebral Glass Particle Mimicking Cavernoma: Case Report

OBJECTIVE AND IMPORTANCE:

Although the presence of a foreign body in the cranium after a head injury is a well-known entity, cases of retained intracranial foreign bodies causing a delayed onset of neurological symptoms are rare. To our knowledge, an unrecognized intracerebral glass particle mimicking a cavernoma has not been previously reported in the literature.

CLINICAL PRESENTATION:

We report a unique case regarding an intracranial foreign body. A 39-year-old patient presented with new-onset epilepsy. The patient had no history of trauma. According to the magnetic resonance imaging findings and the patient's clinical course, the responsible lesion was considered to be a temporal cavernoma.

INTERVENTION:

During the operation, surprisingly, a glass particle was found within the temporal lobe. The glass had penetrated the cranium during a minor head injury and had remained undetected for 33 years. The patient was seizure-free without medication during 3 years of follow-up.

CONCLUSION:

Intracranial small foreign bodies can be difficult to diagnose, especially in patients with no history or a vague history of head trauma. Patients with long-standing retained foreign bodies may remain clinically well until complications arise. Intracranial foreign bodies may mimic other pathologies clinically and radiologically.

Dural metastases mimicking meningioma. Case report and review of the literature

The typical appearance of meningioma on CT and MRI is well known. Particularly in the elderly, the imaging appearance is sometimes considered diagnostic of these benign tumours without histopathological confirmation. However, other more aggressive neoplasms can present with a classical CT and MRI appearance of meningioma, indicating the need for histopathological confirmation wherever possible. We report a case of dural metastases which, on both pre-operative CT and MRI and at surgery, had the typical appearance of a falcine meningioma. Histopathology and immunohistochemistry revealed adenocarcinoma of renal cell origin, and the renal primary was identified on subsequent abdominal investigation. The literature regarding dural metastases is reviewed. To our knowledge, this is the first reported case of a renal carcinoma metastasizing directly to the dura. Although rare, dural metastases can mimic meningioma, and this needs to be considered if conservative therapy or radiosurgery are to be offered to a patient with radiological diagnosis of meningioma.

Textiloma (Gossypiboma) Mimicking Recurrent Intracranial Tumor

Context.—Resorbable substances used to achieve hemostasis during neurosurgical procedures comprise 3 principal classes based on chemical composition: (1) gelatin sponge, (2) oxidized cellulose, and (3) microfibrillar collagen. Nonresorbable hemostatic aides include various forms of cotton and rayon-based hemostats (cottonoids and kites). Resorbable and nonresorbable hemostatic agents have been reported to cause symptomatic mass lesions, most commonly following intra-abdominal surgery. Histologic examination typically shows a core of degenerating hemostatic agent surrounded by an inflammatory reaction. Each agent exhibits distinctive morphologic features that often permit specific identification. Hemostat-associated mass lesions have been variously referred to as textilomas, gossypibomas, gauzomas, or muslinomas.

Objectives.—The aims of this study were to (1) identify cases of histologically proven cases of textiloma in neurosurgical operations, (2) characterize the specific hemostatic agent associated with textiloma formation, and (3) characterize the preoperative magnetic resonance imaging appearance of textiloma.

Design.—Cases in which a textiloma constituted the sole finding on repeat surgery for recurrent brain tumor, or was a clinically significant component of a radiologically identified mass lesion together with residual tumor, constituted the study set.

Results.—Five textilomas were identified and evaluated. The primary neoplasm was different in each case and included pituitary adenoma, tanycytic ependymoma, anaplastic astrocytoma, gliosarcoma, and oligodendroglioma. In all cases, preoperative magnetic resonance imaging suggested recurrent tumor. Textilomas included all categories of resorbable hemostatic agent. Other foreign bodies were present in some cases; the origin of these foreign bodies was traced to fibers shed from nonresorbable hemostatic material placed temporarily during surgery and removed before closure (cottonoids and kites). Inflammatory reactions included giant cells, granulomas, and fibroblastic proliferation. Microfibrillar collagen (Avitene) textilomas were associated with a striking eosinophil infiltration that was not seen with any other hemostatic agent.

Conclusions.—Hemostatic agents may produce clinically symptomatic, radiologically apparent mass lesions. When considering a mass lesion arising after intracranial surgery, the differential diagnosis should include textiloma along with recurrent tumor and radiation necrosis.

Surgical removal of an intramedullary spinal cord foreign body granuloma in a dog

A 2-year-old, spayed female, mixed-breed dog was presented for evaluation of a progressive asymmetric tetraparesis and cranial nerve deficits with a 3-week duration. Computed tomography showed a contrast-enhancing lesion along the left side of the junction of the medulla and the cervical spinal cord. An exploratory surgery determined the presence of an intramedullary lesion of the first cervical spinal cord segment. The mass was removed through a dorsal midline myelotomy. Microscopic examination identified a foreign body granuloma that contained a dense, anisotropic outer wall, supporting the conclusion that the foreign body was of plant origin. The dog recovered to a more improved ambulatory status than prior to surgery.

Clinicopathological Investigation of AVMs Embolized with HEMA-MMA. A New Non-Adhesive Liquid Material

SUMMARY

We have recently developed a non-adhesive liquid embolic agent, hydroxyethylmethacrylate methylmethacrylate copolymer (HEMA-MMA), and used it for arteriovenous malformations (AVMs) in the central nervous system. To evaluate the toxicity and usefulness of this agent, we made a clinicopathological study of AVMs that were embolized with it and then excised surgically. This study includes ten cases: nine with pial AVM and one with scalp AVM. In a pathological study, special attention was paid to vascular and perivascular inflammation, angionecrosis, recanalization of the embolized vessels, and foreign body reactions. Inflammation was absent or very mild regardless of the interval between embolization and excision. There was no angionecrosis. Recanalization could be expected to occur in the partially occluded vessel. Foreign body reactions such as infiltration of monocytes or giant cells, and proliferation of fibroblasts or capillaries were also not seen in any case. It was concluded that HEMA-MMA is an excellent embolic material that is easy to handle, less vasotoxic than other agents, and highly histocompatible.

Foreign body reaction to hemostatic materials mimicking recurrent brain tumor. Report of three cases

Chemical agents routinely used in neurosurgery to achieve intraoperative hemostasis can cause a foreign body reaction, which appears on magnetic resonance (MR) images to be indistinguishable from recurrent tumor. Clinical and/or imaging evidence of progression of disease early after surgical resection or during aggressive treatment may actually be distinct features of granuloma in these circumstances. A series of three cases was retrospectively analyzed for clinical, imaging, surgical, and pathological findings, and the consequences they held for further disease management. All patients were boys (3, 3, and 6 years of age, respectively) and all harbored primitive neuroectodermal tumors. Two tumors were located in the posterior fossa and one was located in the right parietal lobe. Two boys exhibited clinical symptoms, which were unexpected under the circumstances and prompted new imaging studies. One patient was asymptomatic and imaging was performed at planned routine time intervals. The MR images revealed circumscribed, streaky enhancement in the resection cavity that was suggestive of recurrent disease. This occurred 2 to 7 months after the first surgery. At repeated surgery, the resected material had the macroscopic appearance of gelatin sponge in one case and firm scar tissue in the other cases. Histological analysis revealed foreign body granulomas in the resected material, with Gelfoam or Surgicel as the underlying cause. No recurrent tumor was found and the second surgery resulted in imaging-confirmed complete resection in all three patients. Because recurrent disease was absent, the patients continued to participate in their original treatment protocols. All patients remain free from disease 34, 32, and 19 months after the first operation, respectively. During or after treatment for a central nervous system neoplasm, if unexpected clinical or imaging evidence of recurrence is found, a second-look operation may be necessary to determine the true nature of the findings. If the resection yields recurrent tumor, additional appropriate oncological treatment is warranted, but if a foreign body reaction is found, potentially harmful therapy can be withheld or postponed.

Suture granulomas: sonography enables a correct preoperative diagnosis

The purpose of this study was to examine if suture granulomas display distinct sonographic signs and if these signs enable an accurate preoperative diagnosis. In a retrospective and prospective study, the sonographic findings of 22 consecutive suture granulomas were investigated and correlated with subsequent operative results. The sonographic appearance of various surgical sutures in a water bath was also investigated. Sonography was performed with commercially available 5- to 13-MHz linear transducers. The sonographic findings of the suture granulomas included hypoechoic lesions in all cases and hyperechoic double or single lines within the hypoechoic lesions in 20 of 22 cases. Sonography enabled the correct preoperative diagnosis for the investigating radiologists in 20 cases. The sonographic appearance of sutures in a water bath was that of hyperechoic double or single lines. The sonographic signs of suture granulomas (hyperechoic double or single lines within hypoechoic lesions) indicate the correct preoperative diagnosis in a high percentage of cases.

Progress in the diagnosis and treatment of patients with meningiomas. Part I: diagnostic imaging, preoperative embolization

BACKGROUND

The clinical management of patients with meningiomas has changed over the past decade. Change has occurred because of a variety of factors including improved diagnostic imaging, better results with surgery and interventional neuroradiology, and the advent of radiosurgery. Recent clinical studies from several disciplines have provided new information on topics germane to the management of patients with meningiomas. Collecting this information into a series of review articles would have significant value, primarily for neurosurgeons.

OBJECTIVE

The purpose of this first paper is to bring together and evaluate the available data on: 1) noninvasive diagnostic imaging of meningiomas, including magnetic resonance imaging (MRI), computed tomography (CT) scanning, and MR angiography, venography and spectroscopy; 2) the present role of cerebral angiography in patients with meningiomas; and 3) the current status of preoperative embolization for these tumors.

RESULTS

With the advent of MR technology, the quality of diagnostic imaging for meningiomas has improved dramatically, and this is reflected in more sophisticated preoperative planning. MR imaging provides improved delineation of dura and sinus involvement, and even information about a tumor's consistency. Meningiomas have characteristic neuroimaging features, yet other lesions can still mimic a meningioma. MR venography can be used to demonstrate sinus patency, but intra-arterial cerebral angiography gives the most precise information concerning the degree of tumor involvement of critical vascular structures, and the anatomy of arterial feeders. In trained hands, superselective catheterization for preoperative embolization of meningiomas is feasible, and seems to be reasonably safe.

CONCLUSIONS

MR imaging, CT scans, and cerebral angiography can currently be used in a complementary fashion to diagnose, evaluate, and treat patients with meningiomas, with a high degree of clinical certainty. Angiography is used to determine the sites of blood supply to the tumor, which can then be attacked first intraoperatively, making tumor removal easier. Preoperative embolization continues to have value in selected patients, including those in whom the blood supply to the tumor is difficult to access at the time of surgery.