Mesenchymal, non-meningothelial tumors of the central nervous system

[Recommendations for the organ donation from patients with brain or medullary primitive tumors on behalf of the Association of the Neuro-oncologists of French Expression (ANOCEF) and the Club of Neuro-oncology of the French Society of Neurosurgery]

Requests of organs to be transplanted increase. As a matter of urgency, it is not always easy to decide if a patient carrier of a brain tumor can be candidate in the donation. After a review of the literature, the members of the Association of the Neuro-oncologists of French Expression (ANOCEF) and the Club of Neuro-oncology of the French Society of Neurosurgery propose consensual recommendations in case of donor carrier of primitive tumor intra-cranial or intra-medullary. A contact with the neuro-oncologist/neurosurgeon will allow to discuss the indication in case of glioma of grade I/II/III, according to the grade, the current status (absence of progressive disease), the number of surgeries and of lines of treatment. The taking is disadvised in case of glioma of grade IV (glioblastoma), of lymphoma or meningioma of grade III. No contraindication for the meningiomas of grade I, and individual discussion for the meningiomas of grade II. It is advisable to remain careful in case of hemangiopericytoma and of meningeal solitary fibrous tumor. The patients in first complete remission of a medulloblastoma or intra-cranial primitive germinoma seem good candidates for the taking of organ if the follow-up is of at least 10 years (3 years for non germinomas). In every case, a multidisciplinary discussion is desirable when it is materially possible.

Meningeal hemangiopericytoma only diagnosed at the time of late bone metastasis

Hemangiopericytoma is a rare neoplasm. Primary meningeal hemangiopericytomas account for 1 to 7% of all meningeal tumors. In the literature, meningeal hemangiopericytomas are mainly case reports, which confirm an aggressive behavior with a high rate of local recurrence and extracranial metastasis. Metastasis can be seen many years after initial surgical excision of the primary tumor, and the most common sites include the bone, liver and lung. We present a pathological study of four meningeal hemangiopericytomas with bone metastases. All patients are male with a mean age of 46.5 years. Metastases only involved bone. Three out of four lesions were initially misdiagnosed as meningiomas. Only one case was initially correctly diagnosed as meningeal hemangiopericytoma. All patients underwent surgery with complete resection. Only the patient immediately diagnosed with meningeal hemangiopericytoma received postoperative radiation therapy. Three patients had bone metastases without local recurrence including the one who received radiation therapy. One patient recurred locally after 7 years, and bone metastasis was found at the same time. Our cases confirm that meningeal hemangiopericytomas are a separate entity and have a high recurrence rate despite complete surgical resection, with extracranial metastases, mainly to bone, even after long intervals.

Meningial perineurioma: a benign peripheral nerve sheath tumor in a previously unrecognized central nervous system location, mimicking meningioma

Perineurioma is an uncommon, mostly benign, spindle-cell tumor of peripheral nerve sheath origin with a predilection for the soft tissues. Although increasing awareness points to the sites of involvement by perineurioma possibly being as ubiquitous as those frequented by schwannian tumors, only one intracerebral example has been described to date. We report on a surgically resected perineurioma of the falx cerebri in an 86-year-old woman. Preoperative imaging showed an enhancing extraaxial mass of 6 cm × 5.7 cm × 3.7 cm. Histologically, the tumor consisted of a proliferation of spindle cells interwoven by a lattice of basal lamina. Alongside a prevailing soft tissue perineurioma pattern, sclerosing and reticular areas were seen as well. Tumor cells coexpressed EMA and GLUT-1, and a minority immunoreacted for smooth muscle actin. Pericellular basal lamina was decorated with collagen type IV. No staining for S100 protein was detected. Mitotic activity was virtually absent, and the MIB1 labeling index averaged 2%. Ultrastructural examination revealed abundant pinocytotic vesicles within and conspicuous tight junctions between slender cytoplasmic processes which, in turn, were encased by discontinuous basal lamina. FISH analysis confirmed loss of at least part of one chromosome 22q. This observation calls attention to perineurioma as a novel item in the repertoire of low-grade meningial spindle cell neoplasms, in the differential diagnostic context of which it is apt to being misconstrued as either meningioma, solitary fibrous tumor, or neurofibroma. Confusion with the latter bears the risk of overgrading innocuous features of perineurioma as criteria for malignancy.

Primary sarcomas of the brain and spinal cord: a study of 18 cases

Primary sarcomas of the central nervous system are exceedingly rare. We reviewed the clinicopathologic features of 18 primary central nervous system sarcomas diagnosed from 1959 through 1999. Median age at diagnosis of the nine female and nine male patients was 28 years (range 3-63 years). Median tumor size was 4 cm (range 1.3-8 cm). Fifteen tumors arose in the cerebrum (83%), two in the cerebellum, and one in the spinal cord. Histopathologically, the most common tumor types included fibrosarcoma (six), malignant fibrous histiocytoma (five), and undifferentiated sarcoma (three). Immunohistochemical and ultrastructural studies supported the histologic diagnosis in 17 and six cases, respectively. All patients had subtotal to gross total tumor resection; 16 also received radiotherapy and/or chemotherapy. Twelve tumors (67%) were high-grade. Follow-up was obtained in all instances (median 2.3 years). Nine patients died of the disease, eight with high-grade tumors. Survival at 5 years for patients with high-grade tumors was 28% compared with 83% for those with low-grade neoplasms (p = 0.03). Primary central nervous system sarcomas most often affect young and middle-aged adults. Most involve the cerebrum and show fibrous, "fibrohistiocytic," or no specific differentiation. The prognosis for high-grade sarcomas seems better than that for glioblastoma multiforme.

Large solitary fibrous tumor of the kidney: report of two cases and review of the literature

Solitary fibrous tumors are spindle cell neoplasms frequently arising in the serosal surface as well as a variety of other sites. We report two cases of large solitary fibrous tumor arising in the kidney, clinically thought to be renal cell carcinoma, in 41- and 72-year-old men. Although large in size (13.0 and 14.0 cm in greatest dimension, respectively), both lesions were well circumscribed and composed of a mixture of spindle cells and dense collagenous bands with no areas of necrosis or cystic changes noted macroscopically or microscopically. Immunohistochemical studies revealed reactivity for vimentin, CD34, collagen IV, and bcl-2 protein in both cases, with no staining for keratin, S-100 protein, or muscle markers, confirming the diagnosis of solitary fibrous tumor of the kidney. Solitary fibrous tumor of the kidney is rare but may present as a large mass that may be clinically confused with carcinoma or sarcoma.

Primary meningeal sarcomas in two children

Primary meningeal sarcomas are rare but highly aggressive tumors predominantly affecting children. The clinical course, imaging characteristics and histopathological features of meningeal sarcomas in two pediatric patients are presented. Furthermore, we critically discuss the new WHO classification of these entities comparing them to older descriptions. In a 6-year-old girl, a cranial computed tomography (CT) scan was performed, after a mild head trauma, showing a parieto-occipital hemorrhage. One month later, a circumscribed mass adhering to the meninges and with central areas of hemorrhage was evident on magnetic resonance imaging (MRI) scans. Brain biopsy revealed a polymorphocellular sarcoma originating from the leptomeninges and infiltrating the brain. In an 8-year-old girl, who presented with headaches and vomiting, several MRI-examinations were inconspicuous for nearly one year until the latest MR-scan revealed a diffuse contrast enhancement of the leptomeninges of the whole brain and spinal canal. After open biopsy, primary leptomeningeal sarcomatosis was diagnosed. Although CT and MRI did not allow a specific diagnosis in both cases the exact visualization of the extent of the tumor and/or meningeal involvement was possible. Since there are no specific imaging criteria to differentiate meningeal sarcoma from other solid brain tumors or from other tumoral or inflammatory meningioses brain biopsy is indispensable. In order to avoid misinterpretations and delays of therapy, early open brain biopsy or surgical resection of the lesion is necessary in cases of unclear brain masses, especially of unclear meningeal processes. Due to the low number of cases published so far, the biological behavior and clinical management of this tumor entity still awaits further investigation.

Primary Langerhans' cell histiocytosis of the central nervous system with fatal outcome. Case report

An unusual case of primary parenchymal Langerhans' cell histiocytosis of the central nervous system is reported. The definitive diagnosis was obtained by ultrastructural detection of Birbeck granules and by immunohistochemical evidence of CD1a expression. Despite complete surgical resection, there was an early recurrence with multiple central nervous system metastases leading to a fatal outcome.

Solitary fibrous tumor involving the renal capsule

Solitary fibrous tumors are spindle-cell neoplasms that originally were described in the pleura but that can occur in a large variety of sites. We report a well-circumscribed tumor, apparently involving the renal capsule, clinically thought to be a renal-cell carcinoma or oncocytoma. It was composed of bland spindle-shaped cells with a patchy lymphoplasmacytic infiltrate, suggesting sarcomatoid renal-cell carcinoma, inflammatory myofibroblastic tumor, or solitary fibrous tumor; however, immunohistochemical stains were negative for keratin, alpha-smooth-muscle actin, and desmin but strongly positive for CD34. Ultrastructural examination revealed fibroblast-like cells without myofibroblastic or epithelial differentiation. The combined findings favor a diagnosis of a solitary fibrous tumor involving the renal capsule. To our knowledge, this lesion has not been reported in this location.

Intradural extramedullary xanthoma of the spine: a rare lesion arising from the dura mater of the spine: case report

OBJECTIVE AND IMPORTANCE

Xanthomatous tumors of the central nervous system are occasionally found in several unrelated diseases such as Hand-Schüller-Christian disease, Weber-Christian disease, histiocytosis X, malignant fibrous histiocytoma, and a complication of metabolic or storage diseases. However, a solitary xanthoma without systemic disease is rare. We present an unusual case of a solitary and benign xanthoma arising in the spinal leptomeninges without systemic diseases or metabolic abnormality, including a lipid profile.

CLINICAL PRESENTATION

A 16-month-old male patient was admitted with a complaint of spastic paraparesis. His magnetic resonance images revealed an intradural extramedullary tumor that showed isosignal intensity on T1-weighted images and high signal intensity on T2-weighted images with homogenous gadolinium enhancement.

INTERVENTION

The tumor arising from the spinal meninges was totally removed. Histological findings and immunochemical studies positive for CD68 and lysozyme stain showed abundant histiocytic cells with foamy cytoplasm. Negative S-100 protein in the immunohistochemical study and the absence of Birbeck granules on an electromicroscopic study excluded the possibility of Langerhan's histiocytosis. These findings corresponded to xanthoma. The patient had no abnormality of lipid metabolism or familial history of xanthoma.

CONCLUSION

The patient improved enough to walk by himself 3 months after the operation.

Primary osteosarcoma of the cerebrum with immunohistochemical and ultrastructural studies: report of a case

A 57-year-old woman with primary intracerebral osteosarcoma is reported. The tumor was identified by computed tomography as a mass with hemorrhage in the right parietal lobe. The surgical and pathological examinations confirmed an osteosarcoma of intracerebral origin. She suffered from repeated local recurrence of the tumor and died about 1 year after the onset. The pathological findings showed features of osteoblastic osteosarcoma with numerous osteoclast-like multinucleated giant cells. Immunohistochemically, tumor cells were positive for vimentin, and partially for actin. Multinucleated giant cells were reactive with vimentin and CD68 antibodies. Ultrastructurally, tumor cells were rich with rough endoplasmic reticulum. These findings are consistent with the histological features of skeletal or extraskeletal osteosarcoma. This is the third case of primary intracerebral osteosarcoma reported in the literature and the first one analyzed ultrastructurally.

Sclerosing fibrous tumor of the cauda equina: a fibroblastic variant of peripheral nerve tumors?

The case of a 43-year-old man with an unusual mesenchymal tumor of the cauda equina is presented. A well-circumscribed firm tumor was found in the lower spinal canal at L1 level. Although a nerve root was involved, the adjacent dura mater or filum terminale was unrelated to the tumor. Microscopically, the tumor was rich in collagen and made up of irregularly intertwining fascicles of fibroblastic spindle cells lacking in nuclear atypia or mitotic activity. Partial broad hyalinization of collagen was another histological feature of the tumor. Histological and immunohistochemical studies failed to reveal any findings that suggested known fibrous neoplasms, such as schwannoma, neurofibroma and meningioma, originating in the nervous system. Ultrastructural features of the tumor cells were consistent with those of fibroblasts. Hence, the present tumor is regarded as a unique pure fibroblastic tumor (fibroma) derived from the interstitium of a nerve root in the cauda equina.

Primary intracranial sarcomas: histopathological features of 19 cases

Nineteen primary intracranial sarcomas out of a total of about 25,000 brain tumour biopsies are reported. Subtypes included malignant fibrous histiocytoma (6 cases), leiomyosarcoma (3), rhabdomyosarcoma (2), angiosarcoma (2), and one case each of fibrosarcoma, low-grade fibromyxoid sarcoma, malignant ectomesenchymoma, mesenchymal chondrosarcoma, differentiated chondrosarcoma and Ewing's sarcoma. Histological and immunohistochemical features corresponded to those of extracranial sarcomas. Nests of pleomorphic astrocytes mimicking glioma were detected in the five storiform-pleomorphic malignant fibrous histiocytomas. Our results indicate that intracranial sarcomas can be classified like their extracranial counterparts. The low incidence compared with earlier series is related to changes in classification and progress in histogenetic clarification.