Antoni Type Research Articles

A CASE OF RETROPERITONEAL NEURINOMA ARISING IN THE CELIAC PLEXUS

A 50-year-old asymptomatic woman was detected having an abdominal tumor at a medical checkup. abdominal ultrasonography revealed a 3cm-sized circular and internally heterogenous hypoechoic picture at the retropancreatic region and in the right front of the aorta. Abdominal CT visualized a circular, homogenous, and well-defined low density area adjacent to the retropancreatic region and the liver, excepting a part of the center of the area. Angiography showed a stenosis in the left gastric artery and displacement at the root of SMA. ERCP revealed no abnormalities in the bile and pancreatic ducts. The patient was diagnosed as having a retroperitoneal tumor and was operated on. The tumor adhered to the common hepatic artery and celiac artery, where both the tumor and celiac artery existed in a condition enclosed in the plexus. With exposure of the arterial wall the tumor was freed from the artery and excised. The excised tumor was 25×23×20mm in size, elastic soft, encapsulated and well-defined. The section was yellowish brown with hemorrhage in the center. Histopathologically it was Antoni type A neurinoma. No malignancy was detected. Based on intraoperative findings, the tumor appeared to be arised in the celiac plexus.

Schwannomas in Rainbow Smelt

Three rainbow smelt Osmerus mordax with subcutaneous tumors were caught in estuaries at two locations in Nova Scotia and one location off Prince Edward Island. The tumors consisted of a well-circumscribed nodule or series of nodules surrounded by a thin layer of connective tissue containing melanocytes. The surrounding skeletal muscle fibers were often compressed. The tumors were identified as schwannomas, composed of spindle cells arranged in palisades, forming Antoni type A tissue, and less cellular Antoni type B tissue. In one case the nerves of origin of the tumor were compressed to one side of the tumor.

Lectin histochemistry of normal and neoplastic peripheral nerve sheath. 2. Lectin binding patterns of schwannoma and neurofibroma.

Lectin binding patterns of 31 schwannomas and 6 neurofibromas were examined using 12 lectins, and the results were compared with those of normal peripheral nerves. Tumors obtained from 10 cases of neurofibromatosis and 4 recurrent schwannomas were included. Changes of glycoconjugates were observed in association with a neoplastic transformation of Schwann cells; Arachis hypogaea (PNA) staining after neuraminidase treatment seen in normal Schwann cells was reduced in schwannoma of Antoni type A, and bindings with Glycine max (SBA) and Helix pomatia (HPA) after sialic acid removal, which were not seen in normal Schwann cells, appeared in schwannoma cells. Intensities of staining of tumor cells with each lectin were higher in Antoni type B than those in Antoni type A. No differences in lectin binding patterns were observed between schwannomas in patients with neurofibromatosis or recurrent schwannomas and ordinary, primary schwannomas in patients without stigmata of neurofibromatosis. Lectin binding patterns of Schwann cells and perineurial cells in neurofibroma were almost similar to those in normal peripheral nerves with an exception of faint stain of Schwann cells with HPA after neuraminidase pretreatment. This result suggests differences in extent of differentiation between schwannoma cells and neoplastic Schwann cells in neurofibroma. Specific PNA binding to perineurial cells in neurofibroma indicates the significance of this lectin as a marker of these cells.

A Case of a Giant Schwannoma on the Extremities

A 52-year-old Japanese female with a human head sized lump on the medial femoral region of her right thigh is described. The histopathological diagnosis after the excision of the tumor was an ordinary type of schwannoma composed of two types of tissue, Antoni types A and B. The tumor was 20 x 15 x 12 cm in size and 2250 g in weight; this is probably the biggest of all the reported cases of schwannoma on the extremities in Japan.

Histology and neuro-imaging in cystic acoustic neuromas.

Tumor configuration and attenuation on CT scan with contrast enhancement or gadolinium-DTPA-enhanced MR depends upon tumor histology. Various elements are responsible for the density on CT or MR, e.g. blood vessels, fatty tissue, connective tissue, calcium, necrotic tissue, hemorrhage and intra- or extratumoral cyst formation. In a series of 571 acoustic neuromas we found 23 cystic tumors. The diagnosis was based on neuro-imaging examination, confirmed at surgery and finally verified histologically. Eight tumors with small or large cysts were diagnosed by CT or MR scan as intratumoral, and 15 with large cysts were diagnosed as extratumoral. We found a good correlation between the histology of cystic acoustic neuromas and the CT or MR scans. The tumors were predominantly hypodense, corresponding to the cystic areas, but also iso- or hyperdense areas were observed, corresponding to other tissue types. Antoni type B tissue and xanthomatous areas were found in all 23 cases.

舌根部神経鞘腫例

Neurilemmoma at the base of tongue is relatively rare.A 28-year-old female with a tumor at the base of her tongue visited our clinic in February, 1992.Under general anesthesia by oral intubation, the tumor was completely removed extracapsularly through the oral approach. The histopathological diagnosis was Antoni type A neurilemmoma.She has no lingual paralysis or taste loss after the operation, so the origin of the neurilemmoma could not be identified.

Intradural schwannomas of the spine: MR findings with emphasis on contrast-enhancement characteristics.

Intradural extramedullary schwannomas are nerve sheath neoplasms that consist of focal proliferations of Schwann cells involving a spinal nerve. We reviewed the MR findings in seven patients with pathologically proved intradural schwannomas. The contrast-enhancement characteristics on MR images were determined and compared with the histologic features of the tumor. Six lesions were variably hyperintense on T2-weighted images and one was uniformly hypointense compared with the signal intensity of the spinal cord. Signal on T1-weighted images ranged from hypointense to isointense. All seven tumors showed heterogeneous enhancement; in five, the enhancement involved only the periphery of the lesion. The pattern of enhancement did not correlate with the signal characteristics noted on unenhanced T1- and T2-weighted images. Pathologically, hyaline thickening of vessel walls and cyst formation were prevalent in the peripherally enhancing lesions. However, enhancement did not correlate with the relative proportion of Antoni type A and type B tissue. Recognition of the MR characteristics of intradural extramedullary schwannomas may be helpful in the differential diagnosis of spinal tumors. In particular, peripheral contrast enhancement of an intradural extramedullary tumor on MR images should suggest the diagnosis of schwannoma.

Vascular permeability changes in tumours of the peripheral nervous system.

Vascular permeability changes were examined in 34 tumours of the peripheral nervous system by immunohistochemical demonstration of serum proteins as endogenous tracers. The blood-tumour barrier was impaired in the reticular (Antoni type B) portions of neurinomas (Schwannomas) and in cutaneous neurofibromas but was similar to the normal blood-nerve barrier in fibrillary (Antoni type A) neurinomas, in most neurofibromas, in ganglioneuromas and in anaplastic tumours. These differences in permeability are discussed in relation to aspects of pathological tumour vascularization, the histogenesis of microcystic changes, and systemic therapeutic approaches.

頭蓋内に進展した副咽頭腔舌下神経鞘腫例

A 51-year-old male with a history of palsy and atrophy of the right side of the tongue was admitted to our clinic in April, 1991. General physical examination revealed nothing remarkable, and no cafe au lait spots were found. Ultrasound examinations delineated the size and boundary of the neck mass and its relationship to the great vessels. MRI in short spin echo revealed a low density tumor mass. A 3-dimension CT scan showed destruction and enlargement of the jugular foramen and hypoglossal canal. CAG demonstrated a hypovascular mass and no tumor stain. A biopsy was performed via the oral cavity, and the histopathological report was Antoni type B neurinoma, without malignancy.On July 1991, mastoidectomy and suboccipital craniotomy were performed with a staged extracervical approach. The 10th and 11th cranial nerves were intact, but the 12th nerve was involved in a massive cystic tumor which extended intracranially through the enlarged jugular foramen and hypoglossal canal of the skull base. The extracranial 9th nerve was cut because it was involved in the neck mass. Intracranial hypoglossal neurinoma is a rare lesion, and its dumbbell-like extension to the neck is even more rare.The best treatment of this tumor is total removal. However when it is strongly adherent to the medulla, subtotal removal is essential because of the risk of brain damage, since this tumor is benign.

A CASE REPORT OF SCHWANNOMA OF THE RECTUM

Schwannomas of the digestive tract are rare, especially in the rectum. Recently we experienced a case of rectal schwannoma. A 56-year-old female was admitted to our department with the chief complaints of on coccygeal mass and flat stool. The patient was diagnosed as having an extramurally growing neurofibroma of the rectum by Ba-enema, colon fiber, CT, and needle biopsy. The operation was done.Intraoperative frozen section diagnosis disclosed no malignancy, and simple resection of the tumor was carried out. The resected tumor, with dumbell-like shape, was pathologically diagnosed as schwanmoma. Histologically Antoni type A mixed with the type B was identified without malignancy.

Intraocular and Orbital Malignant Schwannomas in F344 Rats

Intraocular and orbital malignant Schwannomas in two F344 rats are presented. The two Schwannomas were identified among approximately 60,000 male and 60,000 female F344 rats. The intraocular malignant Schwannoma occurred in the iris, invading the corneal stroma through the destroyed Descemet membrane. The malignant orbital Schwannoma occurred in the left orbit, invading the contralateral orbit along the optic nerve. Histologically, the intraocular Schwannoma consisted predominantly of a perivascular fascicular pattern of plump spindle cells associated with marked cytoplasmic vacuolization. The orbital Schwannoma consisted of Antoni type A and B pattern, but Antoni B tissues predominated. Antoni A tissues consisted of closely packed, elongated spindle cells arranged in interlacing fascicles, while Antoni B tissues were highly cellular and consisted of anaplastic, small cells associated with marked cyst formation. Immunohistochemically, the intraocular Schwannoma had a positive immunoreactivity for S-100 protein, while the orbital Schwannoma had a negative immunoreactivity. Ultrastructurally, the cells of both intraocular and orbital Schwannomas had long, thin cell processes and pericytoplasmic basal laminae. Particularly, the plump spindle cells of the intraocular Schwannoma were most strikingly characterized by the well developed, extremely attenuated cell processes arranged in a lamellar or spiral pattern. These cell processes and cell bodies were associated with numerous desmosomes. Intracytoplasmic filamentous granules and bodies, consisting of intermediate filaments approximately 7 nm in width, were additional characteristics of the plump spindle cells.

下顎骨中心性神経鞘腫の１例

A 35-year-old man was referred to our hospital with a radiolucency area in the anterior mandibular body on roentogenogram but had no subjective symptoms. Histopathologically there were mild pleomorphism, increased cellurarity and existence of a few mitosis in 100 high power field of biopsy specimen.Partial resection of the mandible was performed. Final histopathological diagnosis was schwannoma Antoni type A intermingled type B of central mandibular body.

Intestinal schwannoma in a rhesus monkey

An intestinal schwannoma (neurilemmoma) was found in an aged female rhesus monkey culled from a research colony. The neoplasm was characterized principally by palisades of spindle-shaped cells (Antoni type A) surrounded by thick argyrophilic fibres, while plump cells with areas of vacuolation (Antoni type B) were observed to a lesser extent. Thick hyalinized perivascular cuffs were prominent and multifocal thromboses were present in cavernous vascular channels. Electron microscopic examination of the intercellular matrix between Antoni type A cells revealed long-spacing (100 to 120 nm) collagen fibrils. Although the mass had expanded beyond the confines of the muscularis externa, the cytological features of the neoplasm appeared benign.

神経鞘腫の５例

Five cases reported as neurilemmoma of the oral cavity in the Second Department of Oral Surgery, Kyushu Dental College Hospital, during the period from 1974 to 1986, were clinically analyzed.1. Five cases of neurilemmoma had been reported. Its incidence was seen in 1.8% of the 247 patients who had undergone incisional biopsy in our clinic.2. Of the five cases, one was located on the lingual dorsum, one in the parapharyngeal space, two on the gingiva near the mental foramen, and the other on the lower lip.3. As to shape of the tumors, all were oval or spherical, and size was between red bean and thumb tip.4. All of five cases occurred in females.5. Histopathologically, all cases were found to be Antoni type A.6. Treatment was performed in all cases by total enucleation and no recurrence was observed up to now.

TWO CASES OF VAGUS NEURINOMA OF THE NECK

We describe two cases of vagus neurinoma of the neck, together with a discussion of therapeutic problems arising from a review of 56 cases reported in Japan. Case 1 was a 27-year-old male who complained of a tumor on the left side of the neck. Palpation revealed a 5×3 cm, smooth surface, elastic-hard, and unmovable tumor at the anterior margin of sternocleidomastoid muscle of the neck. Under general anesthesia enucleation was carried out. During the operation, both upper and lower poles of the tumor were found to present with chordal structures and to be connected to the vagus nerve, and aftet by dividing the vagus nerve, the tumor was extripated. Histologically it was a neurinoma having Antoni type A and B. Immediately after surgery the patient became irreversively hoarse due to recurrent nerve paralysis. Case 2 was a 31-year-old male complaining of a right cervical tumor. Perioperatively, it was definitely diagnosed as vagus neurinoma. The tumor was very small and was presumed to have little possibility of malignancy. Accordingly only partial biopsy was carried out to avoid postopeative complications. In the treatment of vagus neurinoma of the neck, total or subcapsular extirpation should be applied as a rule. However, it may be appropriate for a case without malignancy to avoid extirpation and observe the course.

A CASE OF SCHWANNOMA OF THE MESENTERIUM

We have recently encountered a case of schwannoma of the mesenterium. A 22-year-old woman was admitted with the complaint of an abdominal mass. Ultrasonography and CT scan and CT scan showed a solid mass measuring 10×7cm. Superior mesenterial angiography revealed that the tumor was fed by the jejunal arteries and stained in late phase. It was diagnosed as a solid tumor of the mesenterium of the small intestine. At laparotomy, the tumor was found to be a benign schwannoma of the mesenterium and tumor excision was performed. Histologically, the greater part of the tumor showed Antoni type A, but some part showed Antoni type B. The benign schwannoma of the mesenterium is a rare disease and in Japan only 4 reports have been available including this case. Age, sex, symptoms, diagnosis and treatment were discussed.

Schwannoma of the tongue: Report of a case

Schwannoma occurs in all parts of the body, but occurrence in the oral and maxillofacial regions is relatively rare.Recently we experienced a case of Schwannoma located in the tongue. The patient, a 30-year-old man, visited our hospital with a chief complaint of mass formation in the left side of the tongue. After excision of the tumor under local anesthesia, it was found to be multinodule. Under light microscopy, it showed the picture of Antoni type A. In addition, by an immunohistochemical study using the antibody of S-100 protein, the reactivity in the tumor cell was positive. From electron microscopic findings the tumor consisted of Schwann cells.There was no evidence of recurrence for 7 months after the operation.

The proliferative activity of neurilemomas

Twenty-one patients with neurilemomas (15 intracranial and 6 intraspinal) received a 1-hour intravenous infusion of 5-bromodeoxyuridine (BrdU), 200 mg/m 2 before tumor removal, to label S-phase tumor cells. Excised tumor specimens were stained by the indirect immunoperoxidase method with anti-BrdU monoclonal antibodies to determine the BrdU labeling index, or percentage of Sphase cells. The BrdU labeling index ranged from 0.1% to 3.1% (mean, 0.9%). The BrdU labeling index was >1.5% in four of the 21 tumors (three trigeminal and one spinal). One acoustic tumor in a patient with neurofibromatosis type 1 had a labeling index of 1.3%, which was the highest among the acoustic tumors. The BrdU labeling indices did not correlate with the patient's age, tumor size, or the duration of signs and symptoms. There was no significant difference between the BrdU labeling indices of Antoni type A and Antoni type B tissue. The low BrdU labeling index of most of the intracranial neurilemomas coincides well with the slow growth of these tumors. As the BrdU labeling index may reflect growth potential of individual tumors, it could be used to guide the follow-up of patients with incompletely resected tumor.

口腔領域に発症した神経原性腫ようの２例

It is well known that neurilemmoma and neurofibroma are neurogenic tumors. So those tumors occur where ever neural tissue exists, but are rarely observed in the oral region.Here, we report two cases of neurogenic tumors.Case 1: A 4-year-old boy had a pea size tumor at the lingual side gingiva from B to B in the mandible. Tumor was excised and diagnosed as plexiform neurofibroma.Case 2: A 11-year-old boy had a pea size tumor at the right lower lip. The lesion was diagnosed as a neurilemmoma (Antoni Type A).

Massive Hemorrhage within an Acoustic Neurinoma

A 39-year-old male experienced unilateral right hearing loss and tinnitus for 7 years and was hospitalized after he suddenly developed severe headache, vertigo, and right facial paralysis. Computed tomography (CT) showed a round, high-density are in the right cerebellopontine angle. Magnetic resonance (MR) imaging demonstrated a crescent-shaped region of high signal intensity, representing hemorrhage, in the superior aspect of the tumor, surrounded by edema. The right internal auditory canal was enlarged. Four-vessel angiography disclosed neither an aneurysm nor an arteriovenous malformation. A right suboccipital craniectomy revealed an encapsulated mass 3 cm in diameter in the right cerebellopontine angle. The tumor was totally removed. Histological examination revealed a typical neurinoma composed of Antoni type A and B cells. After undergoing anastomosis of the right hypoglossal and facial nerves, the patient was discharged in good condition. In this case MR imaging demonstrated intratumoral hemorrhage (which is rare in cases of acoustic neurinoma) and the surrounding tissue more clearly than did CT scanning.