Microneurosurgical treatment of intracranial dermoid and epidermoid tumors

Forty-three patients with intracranial, intradural dermoid (8) and epidermoid (35) tumors underwent radical surgical resection utilizing strict microneurosurgical technique. The average age was 37.3 years for the patients with epidermoid tumors and 36.2 years for the patients with dermoid tumors. The male to female ratio was 3:2 for the epidermoid group and 3:1 for the dermoid group. Common clinical presentations included cerebellar dysfunction, cranial nerve impairment, and seizures. Typically, computed tomography scans revealed the epidermoid tumors (30 cases studied) as nonhomogeneous hypodense lesions with irregular borders and without contrast enhancement. The dermoid tumors (7 cases studied) had a similar appearance, but with a wider range of attenuation values. Magnetic resonance imaging findings for the epidermoid tumors (6 cases studied) consisted of increased T1 and increased T2 relaxation times. Supratentorial tumors were excised by the pterional (frontosphenotemporal) approach, mesencephalic tumors by either a supratentorial posterior interhemispheric transtentorial approach or an infratentorial/supracerebellar method, and posterior fossa tumors by either a medially or laterally positioned suboccipital osteoplastic craniotomy. One epidermoid tumor and one dermoid tumor were considered to be subtotally resected because of dense adherences left attached to vital structures; the remaining 41 tumors were completely excised. The most frequent complications were aseptic/chemical meningitis and transient cranial nerve palsies. There were no perioperative deaths. Mean follow-up was 5.2 years. Eighty-six percent of patients reported good to excellent results. No patient had experienced symptomatic or radiographic evidence of recurrence.(ABSTRACT TRUNCATED AT 250 WORDS)

Epidermoid and dermoid cysts. Clinical evaluation and late surgical results

The authors report on the clinical data, operating technique, postoperative complications, and late results in a series of 31 epidermoid and 21 dermoid cysts of the central nervous system.

Comparison of 'pattern recognition' and logistic regression models for discrimination between benign and malignant pelvic masses: a prospective cross validation

OBJECTIVES

To test prospectively the diagnostic performance of two logistic regression models for calculation of individual risk of malignancy in adnexal tumors (the 'Tailor model' and the 'Timmerman model'), and to compare them to that of 'pattern recognition' (subjective evaluation of the gray-scale ultrasound image and color Doppler ultrasound examination).

DESIGN

Consecutive women with a pelvic mass judged clinically to be of adnexal origin underwent preoperative ultrasound examination including color and spectral Doppler examination. The same examination techniques and definitions as those used in the studies in which the logistic regression models had been created were used. The Tailor model was tested in 133 women (35 of whom hada malignancy) and the Timmerman model in 82 women (29 of whom had a malignancy). A subset of 79 women (28 of whom had a malignancy) was used to compare the performance of the Tailor model and the Timmerman model by calculating and comparing the areas under the receiver operating characteristics curves of the two models. Sensitivity and specificity with regard to malignancy were calculated for all three methods.

RESULTS

Pattern recognition performed better than the two logistic regression models (sensitivity around 85%, specificity around 90%). Using a risk of malignancy of > 50% to indicate malignancy (as suggested in the original publications), the sensitivity of the Tailor model was 69% and the specificity 88% (n = 133). The corresponding values for the Timmerman model were 62% and 79% (n = 82). The receiver operating characteristics curves showed the two logistic regression models to have similar diagnostic properties (area under the curve, 0.87 vs. 0.84; P = 0.25; n = 79). The diagnostic performance of the mathematical models was much poorer in this study than in those in which the models had been created.

CONCLUSION

The poor diagnostic performance of the mathematical models can probably be explained by subtle differences in definitions and examination technique and by differences between the original tumor populations and the study population. For mathematical models to be generally useful, they probably need to be created on the basis of a very large number of tumors, and the variables in the model must be unequivocally defined and the examination technique meticulously standardized.

Craniocerebral epidermoids and dermoids. A review of 44 cases

We review 40 epidermoids and 4 dermoids of the skull and brain treated surgically in our Department between 1976 and 1987. Fourteen were extradural and 30 intradural. The mean duration of symptoms was 3 years for extradural and 10 years for intradural tumours. Symptoms varied with tumour site, in some sites being helpful in differential diagnosis. Skull X-rays and CT were the key diagnostic investigations in extradural and CT in intradural lesions, the latter, with few exceptions, presenting a characteristic CT scan. In 7 cases MRI supplied important details on the tumour boundaries. All the diploic and orbital lesions were removed totally, with a good outcome. Twelve of the intradural lesions were removed totally, 9 subtotally and 9 partially, with a good outcome in 21 patients and a poor outcome in 4; 5 patients died. Outcome was unrelated to degree of removal.

Cystic teratoma of the ovary: CT detection

Computed tomography (CT) was performed in 38 patients with 41 benign cystic teratomas of the ovary and two patients with malignant transformation. CT depicted all tumors. The presence of fat in 40 of 43 cases (93%), tooth or calcification in 24 of 43 (56%), Rokitansky protuberance in 35 of 43 (81%), tufts of hair in 28 of 43 (65%), and a fat-fluid level in five of 43 (12%) allowed a definite diagnosis of ovarian cystic teratoma in 42 of 43 cases (98%). In the two cases of malignancy, single large (greater than 10 cm) plugs (with uptake of contrast medium in one) with a cauliflower appearance and an irregular border forming an obtuse angle with the inner wall of the cyst suggested malignant transformation. In three cases of benign cystic teratoma, a mucinous tumor (one benign, one borderline, one malignant) arising in the same ovary was seen at pathologic examination but was only diagnosed with the help of CT in two of three cases. Thickening of the tube was noted in two cases of torsion of the adnexa. CT findings were compared with findings at radiography of the abdomen and hysterosalpingography in 30 cases, ultrasound in 31, and magnetic resonance imaging in three. This study demonstrated that CT was the best procedure for imaging cystic teratomas of the ovary.

Intracranial lipoma. Diagnostic and therapeutic considerations

Eleven cases of intracranial lipoma, diagnosed during life by computerized tomography (CT) scanning, are presented. Clinical symptoms related to the lesions were present in eight. The CT scan established the diagnosis of intracranial lipoma on the basis of typical x-ray absorption and location. Only dermoid cysts and teratomas may produce a similar CT appearance. In cases of intracranial lipoma, a direct surgical approach is seldom necessary, although in certain locations, lipomas may cause blockage of cerebrospinal fluid pathways and require a shunt operation.

Epidermoid tumors. Review of the literature

Reports of epidermoid tumors from 1965 through 1986 were reviewed with emphasis on new and unusual findings. Clinical data considered were rapid onset, rare symptoms, size and rate of growth, and complications. Uncommon locations included multiple sites in one patient and the anterior fontanelle. The radiologic data from computed tomography were the main contributors to diagnosis. An immunohistochemical test disclosed that cells of craniopharyngiomas are keratin-positive. Histologically benign epidermoids can behave as highly malignant tumors, and can become carcinomatous. Postoperative results for benign tumors were often excellent. Evidence was presented of the close relation among epidermoid and dermoid tumor, craniopharyngioma, ameloblastoma (adamantinoma), Rathke's cleft cyst, and aural cholesteatoma.

CT and MRI of ruptured intracranial dermoids

Two patients with ruptured intracranial dermoids, examined with both CT and MRI are reported. Clinical presentation was transient cerebral ischemia in one patient and acute meningeal signs in the other. CT scan showed typical fat density of the tumor and the subarachnoid space. On MRI both the tumor and the subarachnoid fat, were strongly hyperintense on T1-weighted images.

Craniofacial dermoids

Thirty-two patients with nasal dermal sinuses and cysts were treated during the 10-year period from 1978 to 1987. These patients presented with midline cysts (N = 18) or sinus ostia (N = 14). Only 6 of the 32 patients manifested intracranial extension (19 percent). All the patients with intracranial extension exhibited an intracranial mass on preoperative CT scans. Ten patients with no CT evidence of intracranial mass were noted to have only a fibrous cord extending to the base of the foramen cecum. In 4 of these 10 patients, craniotomy confirmed that there was no intracranial extension of the dermoid. Four other patients presented with sinus ostia at the base of the columella. None of these 4 patients had intracranial extension. Clinical examination and preoperative CT scans provide most of the information needed to determine the nature, course, and extent of these lesions.

Diagnosis of epidermoid tumor by computed tomography. Analysis and evaluation of findings

Primary intracranial intradural extraventricular epidermoid tumor may be suggested by the findings on computed tomography (CT), which is also useful during the follow-up period. Epidermoid tumors may exhibit minimal symptoms and have usually spread far beyond their original site by the time they are found. Early detection, delineation, and characterization are possible with CT.

Supratentorial dermoid cysts

Supratentorial dermoid cysts are rare lesions. In eight cases presented here, the lack of recurrence after subtotal removal of the capsule and the good long-term prognosis are emphasized. This finding is in agreement with the literature. The frequent relationship of these lesions with the cavernous sinus suggests a vascular genesis in the development of intracranial dermoid cysts.

Intraventricular mass lesions

Determining the precise etiology of an intraventricular mass can be a difficult diagnostic problem. CT and angiographic findings were reviewed in a series of 73 patients who had intraventricular masses. The histologic diagnosis can be suggested preoperatively by an analysis of the frequency of lesions occurring at a given ventricular location, lesion density before and after administration of contrast material, age and sex of the patient, morphologic appearance of the mass, and presence or absence of hydrocephalus. Angiography is useful when meningioma, choroid plexus papilloma and carcinoma, or arteriovenous malformation are considered. The differential features of each diagnostic entity are discussed.

Craniocerebral epidermoid and dermoid tumours: a review of 32 cases

We reviewed 22 epidermoid and 10 dermoid tumours of the skull and brain from patients operated on consecutively at Henry Ford Hospital between 1975 and 1991. There were 19 intradural (16 epidermoid, 3 dermoid) and 13 extradural (6 epidermoid, 7 dermoid) lesions. The average age at presentation was 35 years for patients with epidermoids and 15 years for those with dermoids. Common clinical presentations for patients with intradural lesions included headache, visual deficits, and seizures, whereas patients with extradural lesions harbored asymptomatic scalp masses. All patients with intradural lesions were investigated with computed tomography (CT) and cerebral angiography, and 8 patients underwent magnetic resonance imaging (MRI). Total resection was possible in 12 (92%) of 13 extradural tumours, all with excellent outcomes. Eight (42%) of the intradural tumours were completely resected. Overall, with the intradural tumours we had good to excellent results in 17 patients (90%), poor results in 1 (5%), and 1 death (5%). Re-operation was needed in 5 intradural recurrences (26%) with deterioration in only one patient's neurologic status postoperatively. From a review of ours and others' data, we conclude that 1) these tumours have an insidious onset despite significant size and mass effect as demonstrated by imaging studies; 2) CT, angiography, and particularly MRI help to define the extent of subarachnoid tumour spread and involvement of neurovascular structures, thus permitting better surgical planning; 3) a significant number of intradural tumours are difficult to excise because of their adherence to neurovascular structures, and thus are related to higher morbidity and mortality; and 4) because of extremely slow growth, complete tumour resection should not be the goal at the risk of injury to neurovascular structures.

Cranial epidermoid tumors: diagnosis by computed tomography

Using seven illustrative cases, the authors discuss the computerized tomographic (CT) appearance of cranial epidermoid tumors. These tumors are of low density (-2 to +10 EMI units), seldom show calcification, and do not enhance with contrast medium. Their differentiation from dermoid tumors and craniopharyngiomas is also discussed.

The variable sonographic appearances of ovarian teratomas: correlation with CT

To better understand how the internal composition of ovarian teratomas influences their sonographic features, we compared their sonographic and CT appearances in 23 cases. Sixteen lesions had a mixed echo texture, with hypoechoic as well as echogenic components; two were anechoic and five were entirely echogenic. Correlation with the CT images showed that the fat present in most teratomas had variable sonographic appearances. Pure sebum was anechoic or hypoechoic, but fat intermixed with hair strands was echogenic and often attenuated the sound beam because of the numerous tissue interfaces created within the mass. The hypoechoic component of the teratoma corresponded, on CT, to low-attenuation fat in 12 tumors and to fluid in five. Most teratomas contained a dermoid plug, a protuberance arising from the tumor wall and containing hair follicles and often fragments of bone or teeth. On sonography, all dermoid plugs were seen as an echogenic mass, often associated with distal acoustic shadowing and protruding into the hypoechoic portion of the teratoma. When the dermoid plug was large and occupied most of the tumor, the entire teratoma appeared echogenic, with no discernible anechoic component. We found that three factors greatly affected the sonographic appearance of ovarian teratomas: the size of the dermoid plug, the presence and location of calcified elements, and the histologic composition of the fatty component.

Scalp and calvarial masses of infants and children

Review of 70 children presenting with a solitary nontraumatic lump on the head revealed that 61% of the lesions were dermoid tumor, 9% were cephalhematoma deformans, 7% were eosinophilic granuloma, and 4% were occult meningoceles and encephaloceles. Most of the dermoid cysts occurred along sutural lines, but some did not. One of the eosinophilic granulomas was located over the sagittal suture. Seventeen per cent of the "lumps" had significant intracranial extension. An additional 20% of the lumps extended intracranially, but only to the dura mater. Work-up of these lesions should include initial plain skull roentgenograms to assess multiplicity and appropriate computed tomographic scans to assess possible intracranial extension.

CT of benign cystic teratomas

The computed tomographic (CT) findings in nine benign cystic teratomas are presented and compared with radiographic, sonographic, and pathologic data. CT rendered a specific diagnosis in six cases and was highly suggestive in two, with results superior to other imaging methods. In each instance, CT was successful in predicting or excluding invasion of adjacent structures, but was not reliable in predicting or excluding adherence to them. Specific CT characteristics of benign cystic teratomas are predominantly fatty mass with a denser dependent element and globular calcification, bone, or teeth in a solid protuberance into the cyst cavity. Suggestive patterns include fatty mass with rim calcification and water density mass with globular calcification and solid tissue elements. Illustrated for the first time are the CT appearances of the different calcifications seen in benign cystic teratomas.

Transnasal endoscopic excision of midline nasal dermoid from the anterior cranial base

We recommend that every patient with a midline nasal dermoid be evaluated preoperatively by fine-cut CT scan, in the axial and coronal planes, using both bone and soft-tissue algorithms. Because of CT limitations for assessing soft tissue at the cranial base, a complementary thin-section, high-resolution, multiplanar MRI scan should be considered. Transnasal endoscopic excision of midline nasal dermoid should be used if the dermoid is located within the nasal cavity, and there is minimal or no cutaneous involvement. This approach can be combined with a short vertical midline lenticular excision of a cutaneous punctum. Vertical cutaneous excision should be limited; the best location is the nasal tip. Vertical nasal scars over the bony pyramid invariably widen no matter what intradermal suture is used. Endoscopic removal should be considered even if preoperative radiologic studies show extension to the anterior cranial fossa. Endoscopic excision could also be used to resect a dermoid extending between the dural leaves of anterior fossa. However, a combined intra-extracranial approach is necessary if the dermoid is in the falx cerebri. We agree with other authors that frozen sectioning the superior margin of the specimen should be done to ensure that there is no intracranial extension. Valsalva maneuver during endoscopic visualization of the cranial base is a valuable means of ruling out a cerebral spinal fluid leak.

Parenchymal cysts of the lower neck

We report on the appearance of parathyroid, thyroid, and cervical thymic cysts on computed tomography (CT) scans. The differential diagnostic considerations include thyroglossal and branchial cleft cysts, cystic hygromas, primary and metastatic tumors, dermoids, teratomas, choristomas, tracheoesophageal and cervical bronchogenic cysts, as well as cystic neuromas, abscesses, and lipomas. Most cannot be differentiated using CT alone and require clinical observations, laboratory testing, and surgical and histologic findings for definitive diagnosis. Our experience with these rare lesions is reported, and the differential diagnoses are discussed.

Conservative management of ovarian cystic teratoma during pregnancy and labor

OBJECTIVE

Our goal was to evaluate the adequacy of conservative management during pregnancy and labor in women with an ultrasonographically diagnosed ovarian cystic teratoma.

STUDY DESIGN

Forty-nine women with ultrasonographically diagnosed ovarian cystic teratoma <6 cm were followed for detection of possible complications through pregnancy and labor. Serial ultrasonographic examinations before pregnancy, during pregnancy, and after delivery were performed to detect changes in the size of the cystic teratoma.

RESULTS

In a group of 49 women with dermoid cysts (mean age, 30 years), 68 pregnancies resulted. Of the 68 pregnancies, 4 ended in miscarriages, 1 was electively terminated, and in the remaining 63 pregnancies, a total of 64 healthy infants were delivered. Five patients needed treatment with assisted reproductive techniques. Fifty-five pregnancies ended in normal vaginal deliveries and 8 were delivered by cesarean (cesarean delivery rate of 16%). None of the classical complications attributed to dermoid cysts such as torsion, dystocia, or rupture occurred in the study group. In a follow-up of 56 dermoid cysts throughout pregnancy, cyst size remained unchanged.

CONCLUSIONS

Ovarian dermoid cysts <6 cm are not expected to grow during pregnancy or to cause complications in pregnancy and labor.

Cranial computed tomography of epidermoid and congenital fatty tumors of maldevelopmental origin

The computed tomographic and clinical findings in 17 patients with fatty intracranial tumors and in 10 patients with epidermoid tumors, all of maldevelopmental origin, are presented. Fat was found in lipomas (the most frequent), dermoids, and teratomas. Differentiation between these tumors is discussed on the basis of density, calcification, location, and symptomatology.

The characterization of common ovarian cysts in premenopausal women

OBJECTIVES

The evaluation of the predictive value of transvaginal ultrasound in the assessment of benign adnexal pathology in premenopausal women, based on the recognition of characteristic morphologic patterns particular to endometriotic and dermoid ovarian cysts.

METHODS

This was a prospective study. All premenopausal women undergoing surgery for a suspected ovarian cyst underwent a transvaginal ultrasound examination in the week prior to surgery. Between June 1997 and January 2000, 132 women underwent surgery for a suspected ovarian endometrioma or dermoid cyst. The endpoints were either the direct visualization of the cyst wall and contents at surgery, or the histologic evaluation of removed tissues.

RESULTS

Of 83 suspected endometriomas (11 bilateral), 80 were confirmed at surgery and of 68 suspected benign cystic teratomas (eight bilateral), 66 were confirmed by histology. The positive predictive value of transvaginal ultrasonography for the diagnosis of endometrioma and dermoid cysts was 96.4% and 97.1%, respectively. The false positive rates were 3.8% and 3.0%, respectively. There were no malignancies in either group.

CONCLUSIONS

Based on the recognition of characteristic ultrasound patterns alone, the positive predictive value of transvaginal ultrasonography for the diagnosis of these common, benign cysts in premenopausal women is very high and can be used reliably to select women for appropriate surgery.