Rhabdoid papillary meningioma.

We have studied an uncommon case of rhabdoid papillary meningioma in a 15-year-old boy with a dura-based mass arising in the left posterior fossa. The patient exhibited prominent extracranial extension during the past 6 years, consisting of a mixture of both perivascular pseudopapillary growth and rhabdoid cytologic features of neoplastic meningothelial cells. The meningothelial features were evidenced by the focal whorl formation of tumor cells, coexpression of epithelial membrane antigen and vimentin, and ultrastructural findings of interdigitated cytoplasmic process and intercellular junction. However, the regional and histologic resemblances to ependymoma were further complicated by unexpected focal expression of glial fibrillary acidic protein, neurofilament, and alpha-smooth muscle actin of the tumor cells. The rhabdoid morphology was characterized by sheets of tumor cells with eccentric nuclei and abundant eosinophilic cytoplasm with often recognizable intracytoplasmic hyaline inclusions. These inclusions revealed ultrastructural paranuclear whorls of intermediate filaments, ruling out the other forms of intracytoplasmic eosinophilic inclusions resembling rhabdoid morphology. Diagnosis of an unusual rhabdoid papillary meningioma with aggressive behavior is resoluble by immunohistochemical and ultrastructural analyses.     

Prominent meningeal "tail sign" in a patient with a metastatic tumor

A prominent enhancement of the dura adjacent to meningiomas has been described as being pathognomonic of these tumors. We describe a case where a classic meningeal "tail sign" was associated with an extra-axial metastatic tumor attached to the tentorium. There was no tumor invasion of the dura. We conclude that this sign is nonspecific and can be seen with dural-based tumors other than meningiomas.     

Undifferentiated (embryonal) sarcoma of the liver. A tumor of uncertain histogenesis showing divergent differentiation.

Pathologic features of eight cases of undifferentiated (embryonal) sarcoma of the liver (USL) in childhood were studied. Light microscopic examination showed a diffuse growth of spindle cells with occasional polygonal cells and multinucleated giant cells and also revealed focal areas of storiform pattern in four tumors, cambium layer formation in one tumor, and alveolar arrangement in one tumor. Immunohistochemical study showed positive staining of proliferating cells for suggestive histiocytic markers (A1AT in 6/6, A1ACT in 5/6, lysozyme in 4/6, and KP1 in 4/6) and for muscle markers (desmin in 4/6 and HHF35 in 3/6). Ultrastructural examination demonstrated that the individual tumors were composed of a mixture of cells having fibroblastic, histiocytoid, fibrohistiocytoid, myofibroblastic, and undifferentiated (primitive mesenchymal) morphologies. Also identified were cells with definite myoblastic morphology in three tumors: leiomyoblastic in one and rhabdomyoblastic in two. In conclusion, the tumor cells in USL show phenotypical diversity comparable to those of malignant fibrous histiocytoma with or without additional rhabdomyosarcomatous or leiomyosarcomatous differentiation.     

Contralateral meningeal artery supply of paramedian meningiomas

BACKGROUND: When resecting at falcine or parasagittal portion of paramedian meningiomas, intraoperative hemostasis often is difficult despite effective management of ipsilateral meningeal arteries. We attribute such difficulties to meningeal artery blood supply from the contralateral side. We retrospectively studied feeding arteries from both sides in case of paramedian meningioma in terms of patient and tumor characteristics. METHODS: Forty-three patients with paramedian meningiomas underwent selective internal and external carotid angiography. We investigated how contralateral meningeal arterial feeders related to patient profiles and imaging, histopathologic, and immunohistochemical findings. RESULTS: Contralateral meningeal supply existed for 14 of 25 falcine meningiomas and 6 of 18 parasagittal meningiomas. Patients with contralateral feeders were 8.5 years younger than the others (P=.027) and were more likely to have larger tumors (P=.028). These were histopathologically malignant (P=.048), while showing more proliferation followed by monoclonal antibody against the Ki-67 antigen index (P=.012) and angiogenetic potential associated with vascular endothelial growth factor expression (P=.0085). CONCLUSIONS: Contralateral meningeal supply may reflect strong angiogenetic recruitment from rapid tumor growth followed by high expression of vascular endothelial growth factor. This angiographical feature may predict the aggressive growth of paramedian meningiomas.     

Leiomyosarcoma of soft tissue in children: clinicopathologic analysis of 20 cases.

Leiomyosarcoma in the pediatric age group is uncommon and incompletely characterized. A series of 20 primary leiomyosarcomas of soft tissue occurring in children younger than 16 years is presented. No significant gender predilection was observed (11 girls and 9 boys). Patient age ranged from 4 to 15 years (median, 12 years). Tumor size ranged from 0.5 to 13 cm (median, 2.5 cm); subcutaneous and deep locations were equally represented. Tumors were evenly distributed among the trunk (30%), head and neck (25%), lower limbs (25%), and upper limbs (20%). All lesions showed at least focally typical features of smooth muscle differentiation, principally in the form of fascicles of eosinophilic spindle cells with cigar-shaped nuclei. An unusual whorled growth pattern was seen in two cases. Morphologic variants including inflammatory leiomyosarcoma (one case), granular cell leiomyosarcoma (two cases), giant-cell rich leiomyosarcoma (two cases), and epithelioid leiomyosarcoma (one case) were seen. Dystrophic calcifications were present in two cases. Most lesions (85%) were low grade. Immunohistochemical staining showed positivity for alpha-smooth muscle actin in 89% of the cases, HHF-35 in 87%, and desmin in 61%. Positivity for cytokeratins, observed in 6 (43%) of 14 cases tested, was usually strong and was diffuse in two cases. Follow-up data, available in 15 (75%) patients (median duration, 49 months), showed late local recurrence in only two cases, one with progression to a higher grade lesion, and no metastasis. These results show that, although extremely rare, soft-tissue leiomyosarcomas do occur in children, in whom they usually present as small morphologically low-grade lesions that seem to behave in a relatively indolent fashion, although longer follow-up data are needed. Differential diagnosis in this setting includes infantile myofibromatosis, leiomyoma, monophasic synovial sarcoma, and spindle cell rhabdomyosarcoma.     

Primary synovial sarcomas of the mediastinum: a clinicopathologic, immunohistochemical, and ultrastructural study of 15 cases

A series of 15 cases of primary mediastinal neoplasms displaying histopathologic, immunohistochemical, and ultrastructural features of synovial sarcoma is presented. The patients' ages ranged from 3 to 83 years, with a male-to-female ratio of 2:1. Nine cases presented as anterior mediastinal masses with chest pain, shortness of breath, and pleural effusion, and 6 cases were in paravertebral location in the posterior mediastinum and presented with neck or back pain and pleural effusion. The tumors measured from 5 to 20 cm in greatest diameter and showed a tan white, soft to rubbery cut surface with areas of hemorrhage and necrosis and foci of gelatinous material. Four cases showed areas of cystic degeneration. In 7 cases, the tumors were well circumscribed; in 6 cases, the tumors grossly invaded the pleura, pericardium, heart, great vessels, chest wall, rib, and vertebra. Histologically, 5 cases displayed a biphasic growth pattern, with well-formed glandular elements admixed with a monotonous spindle cell population. Ten cases were exclusively composed of a monotonous atypical spindle cell proliferation. Immunohistochemical studies showed focal positivity of the tumor cells for cytokeratin and/or epithelial membrane antigen, and strong positivity for vimentin and bcl-2 in the spindle cells in all cases studied (10 of 10). Eight cases also showed focal positivity for CD99. Electron microscopic examination in 5 cases showed oval to spindle tumor cells with closely apposed cell membranes, abundant cytoplasmic intermediate filaments and rough endoplasmic reticulum, and immature desmosome-type cell junctions. Ten patients were treated by complete surgical excision and two by partial excision followed by radiation therapy. In 4 patients, the tumors were inoperable and treated with radiation therapy only. Clinical follow-up was available in 5 patients and showed local recurrence with metastases to lung, lymph nodes, and epidural space from 1 to 3 years in 4 cases and liver metastases and death due to tumor after 6 month in 1 case. Synovial sarcoma should be considered in the differential diagnosis of biphasic and monophasic spindle cell neoplasms of the mediastinum.     

Nodular Fasciitis of the Oral Cavity with Partial Spontaneous Regression (Nodular Fasciitis)

Nodular fasciitis is a lesion found in the subcutaneous fascia that micoscopically presents as a benign proliferation of fibroblasts and myofibroblasts, which may be mistaken for a sarcoma due to clinically rapid growth. Diagnosis is by histopathology and of the immunohistochemical profile. We describe a case of nodular fasciitis in the oral cavity that demonstrated partial spontaneous regression. The patient was a 32-year-old man with a buccal mucosal mass, which had grown rapidly for 45 days. On microscopic examination, the lesion displayed a well-delineated but not encapsulated proliferation of spindle cells, with a nodular growth pattern. Immunohistochemical analysis showed positivity of the spindle cells for the antibodies against smooth muscle actin and muscle-specific actin (HHF-35). Treatment of such lesions typically involves complete conservative excision, but the lesion may regress eventually in the absence of definitive treatment.     

A new subtype of meningioma

Three patients with small meningiomas presented with diffuse cerebral edema that was out of proportion to the size of tumors. All lesions were small and no brain invasion or unusual tumor vascularity or dural sinus involvement was noted in any of the three cases. Tumor material was subjected to conventional and immunohistochemical stains. All three tumors showed benign meningothelial components, prominent formation of hyaline inclusions (pseudopsammoma bodies), and striking vascular mural proliferation of small dark cells. All patients have remained asymptomatic without any evidence of tumor recurrence after a follow-up of 4-6 years. These tumors showed proliferation of pericytes in blood vessel walls and, therefore, represent a new subtype of meningothelial meningioma. In the study presented here, the location, size, histotype, and clinical findings that may influence the development of peritumoral brain edema are discussed in detail.     

Intracranial meningeal melanocytoma: a report of two cases and a review of the literature

Two rare cases of intracranial meningeal melanocytoma are reported with clinical, radiologic, and pathologic findings. In one of these the diagnosis was established by ultrastructural studies that showed premelanosomes and melanosomes in nonarachnoid-derived tumor cells. The other case was diagnosed retrospectively after a very long survival and is still alive 35 years after total excision and radiotherapy. The occurrence of these tumors in the cerebellopontine angle is rare as seen in our case.     

Meningiomas. Diagnostic value of immunoperoxidase staining for epithelial membrane antigen

Meningiomas are composed of cells which display both mesenchymal and epithelial features. To investigate the epithelial nature of these cells, we studied the distribution of epithelial membrane antigen (EMA) in 22 meningiomas; for comparison, we also studied eight central schwannomas, neoplasms with which meningiomas sometimes may be confused histologically. All 22 meningiomas (12 transitional, six meningotheliomatous, three fibroblastic, and one psammomatous) demonstrated immunoreactive EMA, whereas all eight schwannomas were EMA-negative. There was no consistent relationship between histologic growth pattern and nature of EMA staining in the meningiomas: meningothelial areas, spindle cell areas, and whorls all showed EMA immunoreactivity of varying degrees. We also evaluated the distribution of S-100 protein and keratin in these tumors. All schwannomas showed diffuse S-100 positivity, which was often more intense in the nuclei than in the cytoplasm. In nine meningiomas (41%), S-100 immunostaining was observed, but this was usually focal, and nuclear staining was never more intense than cytoplasmic staining. One meningioma, but none of the schwannomas, showed clusters of keratin-positive cells. We conclude the following: EMA immunoreactivity is a characteristic feature of meningiomas, regardless of pattern of growth, and the combination of immunoperoxidase staining for EMA and S-100 protein may be used to distinguish meningiomas from schwannomas in problematic cases.     

Intracranial meningeal hemangiopericytoma metastatic to the scapula

Meningeal hemangiopericytomas are rare vascular tumors that have a propensity for recurrence and metastasis. Intracranial hemangiopericytomas are rare vascular tumors. They account for 0.5% of primary central nervous system tumors and 2% of meningiomas. Unlike usual benign meningiomas, which rarely metastasize extracranially, meningeal hemangiopericytoma has a high rate of local recurrence and distant metastasis. The treatment paradigms for hemangiopericytomas and meningiomas differ based on their biological behaviors. Hemangiopericytomas have higher rates of recurrence and metastasis compared with meningiomas. Intracranial meningeal hemangiopericytoma is characterized by clinically repeated local recurrences at the primary site. Bone, liver, lung, central nervous system, and abdominal cavity are the most commonly reported sites of metastasis in hemangiopericytomas.This article describes a case of bone metastasis with extensive involvement of the scapula from intracranial hemangiopericytoma. Bone metastasis can be seen in a relatively late phase of the disease, with metastasis to other organs. Although radiation therapy is effective in controlling pain from bone metastases in unresectable disease and those with extensive visceral metastases, aggressive local surgical control of a solitary bone metastasis may be an option for patients with limited distant disease. The diagnosis may be initially confused with clear cell meningioma and benign meningiomas. The management of bone metastasis is not well reported in the orthopedic literature.     

Rhabdomyosarcoma of the duodenum: report of a case

This report presents a case of primary pleomorphic rhabdomyosarcoma arising in the duodenum. A 63-year-old male with persistent melena was referred for a solid tumor in his right upper abdomen detected using ultrasonography. Gastrofiberscopy revealed a protrusion in the upper part of the duodenum, with a large ulcer on the top of it. Enhanced computed tomography showed that the tumor extended to the pancreas. Pancreaticoduodenectomy was performed, despite the absence of malignant cells in the biopsy specimen, with a preoperative diagnosis of duodenal cancer. The tumor consisted of multiple cell types, and immunohistochemical staining was positive for desmin, HHF-35 and alpha smooth muscle actin. Electron microscopy revealed primitive Z-band structures in the tumor. The final diagnosis was pleomorphic rhabdomyosarcoma of the duodenum. This is the first report of primary rhabdomyosarcoma occurring in the duodenum, confirmed by immunohistochemical staining and electron microscopy.     

Meningioma, meningeal hemangiopericytoma (angioblastic meningioma), peripheral hemangiopericytoma, and acoustic schwannoma. A comparative immunohistochemical study

The relationship between meningeal hemangiopericytoma (angioblastic meningioma), meningiomas of meningothelial derivation, and peripheral hemangiopericytoma is controversial; and immunohistochemical studies have yielded conflicting results. Likewise, immunohistochemistry has been touted as a reliable means of differentiating fibrous meningioma from acoustic schwannoma. By the immunoperoxidase method, we studied 40 meningiomas (11 meningotheliomatous, four transitional, 11 fibrous, three secretory, four metaplastic, one xanthomatous, one papillary, four atypical, one malignant), five arachnoid granulations, 13 angioblastic meningiomas, nine peripheral hemangiopericytomas, and seven acoustic schwannomas. Antisera to vimentin, epithelial membrane antigen (EMA), keratin, S-100 protein, carcinoembryonic antigen (CEA), desmin, factor VIII, Ulex europeaus, and glial fibrillary acidic protein (GFAP) were utilized. All meningiomas and arachnoid granulations stained for vimentin and EMA; 15% and 12% of meningiomas were S-100 and keratin positive, respectively. The latter was noted primarily in areas of secretory (pseudopsammomatous) differentiation. In contrast, all angioblastic meningiomas stained for only vimentin. This profile of immunoreactivity was also seen in the peripheral hemangiopericytomas, with the exception of single cases that stained focally for EMA and S-100 protein, respectively. Acoustic schwannomas all stained positively for S-100 protein, vimentin, and were variably reactive for EMA, a pattern not distinct from meningioma. We conclude that (a) meningiomas express both epithelial and mesenchymal markers as do arachnoid granulations, (b) that angioblastic meningiomas demonstrate only mesenchymal markers, (c) that angioblastic meningiomas express identical markers to peripheral hemangiopericytoma and should thus be considered a variant thereof, (d) among meningiomas, CEA and keratin appear to be relatively specific markers for the "secretory" variant, and (e) because of overlap in S-100 and EMA reactivity, these markers are unreliable in differentiating meningioma from acoustic schwannoma.     

Early malignant transformation of a petroclival meningothelial meningioma

Although some authors have reported the malignant transformation of meningiomas, there has been no previous report describing that a meningothelial meningioma transformed into an atypical meningioma within 1 year. This report documents a 57-year-old woman who presented with right hearing disturbance. Magnetic resonance imaging revealed a right petroclival meningioma. The tumor was subtotally removed and was diagnosed to be a meningothelial meningioma. Seven months after surgery, a recurrence of the tumor was confirmed. The diagnosis of this recurrent tumor was an atypical meningioma. The MIB-1 index and the percent of p53 protein-positive cells in the primary tumor were 4.6% and 35.4%, respectively, whereas those of the recurrent tumor were 34.7% and 33.1%, respectively. A chromosomal DNA copy number loss was observed on 1p, 6q, 10, 14q, and −22q detected in both the primary and the recurrent tumors. These results suggest that the present case had a potentially malignant tumor in the early stage, although it had the histological features of benign meningiomas. An evaluation of the MIB-1 index, as well as the expression of p53 and chromosomal aberrations, may be useful for predicting the malignant transformation of meningiomas.     

Inflammatory myofibroblastic tumor of the rectum in a 13-month-old girl: a case report

Inflammatory myofibroblastic tumor is a rare benign neoplasm. It is common in children and has been reported in various locations throughout the body but rarely in the rectum. A 13-month-old girl presented with a short history of a painless anal mass and no hematochezia. The mass was completely excised, and histologic examination of the initial biopsy showed fascicles of spindle cells in a mixed inflammatory background with predominance of plasma cells, typical of an inflammatory pseudotumor. The spindle cells were positive for smooth muscle actin and anaplastic lymphoma kinase staining. There is no evidence of recurrence or metastasis after a follow-up of 4.5 years.     

Spindle epithelial tumor with thymus-like differentiation (SETTLE) of the thyroid

BACKGROUND: Tumors of the so-called intrathyroidal epithelial thymoma type are a rare group of thyroid neoplasm tumors. Of this type of tumor, spindle epithelial tumor with thymus like differentiation (SETTLE) has been reported only 17 times in English literature. METHODS: An 18-year-old woman was initially seen with a 6-cm left thyroid mass that was resected with a left thyroidectomy. Histopathologic features of the excised left thyroid tumor together with an immunohistochemistry and electron microscopy led us to a diagnosis of SETTLE. RESULTS: Most of the specimen was composed of highly cellular spindle cells that formed intersecting and streaming fascicles. The spindle cells showed both vimentin immunoreactivity and cytokeratin immunoreactivity but no immunoreactivity for thyroglobulin or calcitonin. Electron microscopic examination of the spindle cells demonstrated prominent cytoplasmic tonofilaments, desmosomes, and basal lamina consistent with epithelial cell origin. DNA content analysis by flow cytometry revealed DNA diploidy. CONCLUSIONS: SETTLE of thyroid gland is an extremely rare entity. A review of the literature reveals that SETTLE has distinctive morphologic features and an immunohistochemical profile.     

Secretory meningioma. A distinct subtype of meningioma

Six meningiomas with abundant hyaline inclusions (pseudopsammoma bodies) were studied. As seen by light and electron microscopy, hyaline inclusions are composed of material of varying structures located in intracellular lumina lined by microvilli. A remarkable pericytic proliferation within the vessel walls was found in five cases. In all six cases, immunohistochemical examination for multiple antigens showed positive staining for carcinoembryonic antigen and epithelial membrane antigen in inclusions and surrounding cells. Weak positivity was found for keratin and secretory component in five cases and for alpha-1-antitrypsin and IgM in four cases. It is concluded that secretory meningioma is a distinct type of meningioma, usually meningothelial in type. It shows characteristic light-microscopic, ultrastructural, and immunohistochemical features of epithelial and secretory differentiation with accumulation of secretory material in the form of hyaline inclusions; marked vascular pericytic proliferation is also frequently present.     

Recurrence in meningeal hemangiopericytomas

BACKGROUND Meningeal hemangiopericytomas are more aggressive than typical meningiomas, with a high rate of recurrence and distant metastases. The question of whether a correlation exists between prognosis and histologic features remains controversial.

CASE DESCRIPTION

We report two cases of recurrent meningeal hemangiopericytomas. Although local growth control of the tumor was obtained by tumor removal and irradiation in a 38-year-old male patient (Case 1) with a recurrent tentorial tumor, the tumor disseminated and metastasized extracranially within a short period after treatment, leading to rapid deterioration. Another 38-year-old female patient (Case 2) with a recurrent orbital tumor had a favorable outcome after tumor removal. The Ki-67 proliferative index using the MIB-1 monoclonal antibody increased as the tumor recurred in Case 1 (2.5%, 7.9%, and 15.7%), but did not change between primary and recurrent tumors of Case 2 (4.2%, 3.1%). Immunostaining for p53 protein in Case 1 was negative at the first resection, and became positive at the second and third resections, whereas in Case 2, it was negative in both the primary and recurrent tumors.

CONCLUSIONS Our results suggest that p53 protein accumulation with a high proliferative potential is a useful marker to estimate malignant progression in meningeal hemangiopericytomas.     

Meningiomas of the Internal Auditory Canal: Two Case Reports

Meningiomas represent 3 to 12% of the tumors that involve the cerebellopontine angle and internal auditory canal (IAC). Intracanalicular meningiomas, however, are rare. Only 10 well-documented cases have been reported in the English literature. The differential diagnosis includes acoustic neuromas, facial nerve neuromas, hemangiomas, lipomas, and meningiomas. We report two new cases of intracanalicular meningioma. Both patients had unilateral tinnitus. In case 1, the patient also experienced sensorineural hearing loss with unilateral tinnitus. In case 1, the lesion appeared hyperintense on T1-weighted and hypointense on T2-weighted magnetic resonance images. In case 2, the patient had an enhancing lesion in the right IAC. The tumors were moderately cellular, and meningeal whorls and meningothelial inclusions were present. Immunohistochemical staining revealed the tumors to be positive for epithelial membrane antigen (EMA) and negative for S-100 protein. The radiologic findings that help distinguish a meningioma from other lesions are reviewed.     

Expression of BCL-2 oncoprotein on tumor cells and tumor-infiltrating lymphocytes (TIL) in meningiomas

The Expression of the antiapoptotic oncoprotein BCL-2 and its correlation to tumor grade in 62 meningiomas (48 classic, 9 atypical, and 5 anaplastic) using single and double immunohistochemistry was investigated. BCL-2 expression was found in two different cell populations identified as lymphocytes (BCL-2+CD3+) and tumor cells (BCL+/CD3–). Tumor-infiltrating lymphocytes (TIL) (CD3+) were found within classic (9.5% of cells), atypical (2.4% of cells), and anaplastic (1.8% of cells) meningiomas. In classic meningiomas, 66.5% of TIL were BCL-2-positive, in atypical meningiomas 79.2%, and in anaplastic meningiomas 37.9%. In 33 (68.8%) of the classic meningiomas, medium to high counts of BCL-2+ tumor cells were detected. Atypical meningiomas showed nearly equal percentages of high (two patients), medium (five patients), and low (two patients) BCL-2+ tumor cell counts, whereas anaplastic meningiomas showed only medium (two patients) and low (three patients) BCL-2 tumor cell counts or were BCL-2-negative (one patient). In summary, a significant inverse correlation between the number of BCL-2-positive tumor cells and tumor grade in meningiomas was found. These findings support the hypothesis of cell survival prolongation by the antiapoptotic ability of BCL-2 proto- oncogenes and demonstrate the prognostic relevance of BCL-2 immunoreactivity in meningiomas. Received: 10 June 1998 / Accepted: 23 February 1999