Meningioma of the scalp: a case report with immunohistological features

Cutaneous meningioma

Cutaneous meningioma is a rare tumor that most commonly occurs on the scalp and occurs in both congenital and acquired forms. It invokes a wide clinical differential diagnosis, but diagnosis is based on characteristic histologic and cytologic findings. Congenital lesions can often present years after birth and even in adult patients. Acquired lesions occur in adulthood. We review histologic, cytologic, and electron microscopic findings and explore how these are used to separate this entity from other entities in the differential diagnosis. While ultrastructural and cytologic findings are similar to those of more common intracranial meningiomas, these tumors exhibit a range of histologic differences. A lack of awareness of this entity precludes correct diagnosis.

Large, papillomatous, pedunculated nevus sebaceus: a new phenotype

We present five cases of an unusual phenotype of nevus sebaceus characterized by large, pink, exophytic nodules. In all cases, no evidence of extracutaneous disease or associated syndromes was observed. We review the clinical presentation of nevus sebaceus, the differential diagnosis of exophytic scalp tumors in the newborn, as well as management of these lesions.

Primary intra-diploic meningioma in a child

BACKGROUND

Primary intra-diploic meningiomas are uncommon in childhood and, at the clinical onset, may be confused with other and more frequent bone tumours because they lack specific clinical and radiological characteristics. Surgery is indicated not only to remove the lesion but also to obtain an accurate histological diagnosis.

CASE REPORT

We report the case of a young girl who presented with a recently developed subcutaneous hard mass in the left pterional region. Neuroradiological investigations revealed an intra-osseous lytic mass with a sclerotic reaction. Diagnosis was possible only after the total removal of the tumour and its histological examination.

Meningioma of the mandible: imaging with CT

We present the first description of CT of a meningioma of the mandible in the literature. Extracranial meningiomas are exceedingly rare. There have been 3 cases of meningioma of the mandible described in the literature, but none characterized with cross-sectional imaging. We describe the clinical and CT features used to establish the diagnosis as well as how to differentiate this lesion from other pathology of the mandible.

Dural involvement in primary extradural meningiomas of the cranial vault

Object

The authors retrospectively analyzed a consecutive series of patients with cranial vault primary extradural meningioma (PEM), with particular regard to the tumor’s dural involvement. The pertinent literature was reviewed.

Methods

Clinical data were retrospectively obtained in a consecutive series of 16 patients treated for a PEM at two institutions between 1992 and 2004. The authors created a classification system based on dural involvement of the tumors.

Nine women and six men (mean age 55 years) presented with a painless, slowly progressive swelling. Preoperative magnetic resonance (MR) imaging revealed dural enhancement at the site of tumor in 11 patients. On surgical inspection, the tumor infiltrated the dura in all but three patients. Histological examination of tissue samples demonstrated tumor infiltration of the dura in all 14 patients in whom the dura had been resected. Three recurrent tumors were observed on follow-up examination during a mean period of 5.8 years (range 1.5–13 years) and required extirpation. In addition to one patient in whom there was histological evidence of malignancy, the other two cases involved two patients in whom no apparent dural involvement was observed during the first surgery. In a review of the literature, the authors found that histological examination showed dural involvement in 22%; the dura was not histologically evaluated in the remaining patients (78%). Postoperative follow-up data exceeding 2 years were only provided in two of the reported cases.

Conclusions

Tumor infiltration of the dura should be assumed in PEMs of the cranial vault, and resection of the dura at the site of craniotomy is recommended to prevent tumor recurrence.

Primary extradural meningiomas: a report on nine cases and review of the literature from the era of computerized tomography scanning

OBJECT

Primary meningiomas arising outside the intracranial compartment (primary extradural meningiomas [PEMs]) are rare tumors. To develop a better understanding of these tumors and to establish a comprehensive classification scheme for them, the authors analyzed a series of patients treated at the M. D. Anderson Cancer Center (MDACC) and reviewed all cases reported in the English-language literature since the inception of the use of computerized tomography (CT) scanning.

METHODS

Clinical records, results of radiographic studies, and histological slides were reviewed for all cases of PEM at MDACC. Demographic features, symptoms, tumor location, histological grade, and patient outcome were assessed in all cases. A comprehensive literature search identified 168 PEMs in 142 patients reported during the CT era. These reports were also analyzed for common features. Tumors for both data sets were classified as purely extracalvarial (Type I), purely calvarial (Type II), and calvarial with extracalvarial extension (Type III). Type II and Type III tumors were further categorized as convexity (C) or skull base (B) lesions. The incidence of PEMs at MDACC was 1.6%, which was consistent with the rate reported in the literature. In both data sets, the male/female ratio was nearly 1:1. The most common presenting symptom was a gradually expanding mass. The age of patients at diagnosis of PEM was bimodal, peaking during the second decade and during the fifth to seventh decades. In all MDACC cases and in 90% of those reported in the literature the PEMs were located in the head and neck. The majority of tumors originated in the skull (70%). In the MDACC series and in the literature review, the majority (67% and 89%, respectively) of tumors were histologically benign. Although fewer PEMs were malignant or atypical (33% at MDACC and 11% in the literature), their incidence was higher than that observed for primary intracranial meningiomas. Distant metastasis was not a common feature reported for patients with PEMs (6% in the literature). Outcome data were available in 96 of the cases culled from the CT-era literature. The combination of the MDACC data and the data obtained from the literature demonstrated that patients with benign Type IIB or Type IIIB lesions were more likely to experience recurrence than patients with benign Type IIC or Type IIIC tumors (26% compared with 0%, p < 0.05). The more aggressive atypical and malignant tumors were associated with a statistically significant higher death rate (29%) relative to benign tumors (4.8% death rate, p < 0.004).

CONCLUSIONS

Defining a tumor as a PEM is dependent on the tumor's relation to the dura mater and the extent and direction of its growth. Classification of PEMs as calvarial or extracalvarial and as convexity or skull base lesions correlates well with clinical outcome.

Retroperitoneal malignant meningioma. A light microscopic, immunohistochemical, and ultrastructural study

Malignant meningiomas are uncommon and rarely occur outside the central nervous system. We describe herein a morphologically unusual malignant neoplasm that arose in the retroperitoneum of a 25-year-old woman. The tumor was composed of sheets of epithelioid cells that were frequently arranged in prominent whorls. By electron microscopy, the neoplastic cells had long, tapering cell processes that formed numerous interdigitations; many junctions including desmosomes; and abundant intermediate filaments. Immunohistochemistry showed that the tumor cells expressed vimentin, keratin, and epithelial membrane antigen. Based on these findings, the neoplasm was classified as a malignant meningioma. According to our review of the literature, this is the first reported occurrence of a primary retroperitoneal meningothelial neoplasm and the second reported case of an ectopic meningioma that was malignant.

Primary cutaneous meningioma associated with von Recklinghausen's disease

Cutaneous meningeal tumors are rare and can pose a diagnostic problem. We present a case of a 12-year-old girl with a family history of von Recklinghausen's disease. The patient was asymptomatic until the age of 11, when she developed two lesions on the head, both diagnosed as plexiform neurofibroma. Subsequently, she presented with a subcutaneous nodule on the left posterior occipital scalp which was excised. On histology, the tumor was composed of spindle-shaped cells with diffuse and nested patterns. A whorled configuration of the cells, with occasional giant cells and psammoma bodies, was present. There was no evidence of connection between the tumor and the underlying tissues. Immunohistochemical studies were positive for epithelial membrane antigen, vimentin, and weakly for neuron-specific enolase. Cytokeratin, S-100 protein, and muscle markers were negative. Based on these features, the diagnosis of cutaneous meningioma was made. An MRI examination failed to detect any communication between the tumor site and the meninges; however, asymptomatic bilateral acoustic neuromas were identified. This case, besides being of interest as a primary cutaneous meningioma, also documents a unique combination of findings, i.e., plexiform neurofibroma, meningioma, and cerebellopontine acoustic neuromas, which should alert the clinician to a forme fruste presentation of von Recklinghausen's disease.

Perineurioma (storiform perineurial fibroma): clinico-pathological analysis of four cases

Four cases of perineurioma (storiform perineurial fibroma) arising in the dermis, subcutis, or deep soft tissue have been studied. Two patients were female and two were male with ages ranging from 19 to 45 years. One lesion each arose on the chest wall, shoulder, neck, and elbow. Follow-up information in three patients revealed no recurrence. Histologically, the neoplasms were circumscribed but non-encapsulated lesions and were composed of spindle cells with elongated bipolar cytoplasmic processes, inconspicuous fusiform nuclei and well-defined palely eosinophilic cytoplasm. These cells were arranged in whorls or lamellar-like structures and often demonstrated a storiform growth pattern. In areas, the tumour cells appeared larger with more rounded nuclei. Immunohistochemically, most of the tumour cells stained positive for epithelial membrane antigen and vimentin, but failed to stain for S-100 protein, neurofilament, desmoplakin, and CD34. Ultrastructurally, two cases showed fusiform tumour cells with long, thin cell processes separated by abundant collagen bundles. Tumour cells were covered by discontinuous external lamina, showed many pinocytic vesicles and occasionally desmosome-like structures. The morphology and EMA immunopositivity of perineurioma are similar to meningioma, especially to cutaneous meningioma type II. We believe that perineurioma and meningioma are closely related, but morphologically distinguishable, neoplasms.

Cutaneous meningioma underlying congenital localized hypertrichosis

A 28-year-old man had a circumscribed hypertrichotic area on the left lumbar region since birth. A biopsy specimen showed numerous normal-appearing hair follicles and arrector pili muscles. In the subcutaneous layer a mass of dense collagenous connective tissue formed the background in which ill-defined foci of meningothelial cells in nests and pseudovascular spaces were seen. Collagenous structures (pseudopsammoma bodies), some of which showed calcification (psammoma bodies), were also seen. A diagnosis of cutaneous meningioma was made.

Malignant meningioma of the scalp

A nodule from the scalp of a 14-year-old boy was diagnosed by light and electron microscopy as a meningioma. There was no evidence of an intracranial lesion or involvement of the bone of the skull. The tumor was excised but recurred and metastasized to lung and chest wall.

Meningeal hamartoma of the scalp. A variant of primary cutaneous meningioma

A case of meningeal hamartoma of the scalp is reported. A 15-year-old girl was admitted complaining of scalp nodules in the midline occipital region. A midline skull defect was found under the nodular lesions. Histologically, the mass had a fibrocollagenous tract extending to the dura and showed an admixture of mature adipose tissue, small vessels, strands of fibrocollagenous tissue, and scattered foci of meningocytes. Immunohistochemically, the meningocytes desmosomes, interdigitating processes, and intermediate filaments. The patient's brother also had the meningeal hamartoma of the scalp. Meningeal hamartoma as a variant of primary cutaneous meningioma is extremely rare, and this is the first report of such a case in Japan.

An unusual benign neural tumour with stellate-cell morphology

We report a stellate-cell dermal tumour which was studied by immunohistochemistry and electron microscopy. The stellate morphology of the tumour cells appeared to be due to retraction of their cytoplasm resulting in the emergence of intercellular spaces. Results of the immunohistochemical investigations were consistent with a neural tumour, but we could not assign it to any particular category of the known neural tumours. Therefore we have designated this tumour as an unusual, benign, neural-tumour with stellate-cell morphology.

Rudimentary meningocele of the skin. Clinicopathologic features and differential diagnosis

Although "rudimentary meningocele" (RM) or "meningothelial hamartoma" of the skin is a seemingly recently described entity, it has been included in past reports as a variant of primary cutaneous meningioma. We document our experience with four such lesions and compare the histologic and immunohistochemical features of these cases with those of seven classic meningoceles (CM) and four giant cell fibroblastomas (GCF). Although all of these entities share significant points of microscopic similarity, RM and CM are lesions composed of meningothelial cells, whereas GCF is probably of myofibroblastic origin. Rudimentary and classic meningoceles demonstrate cellular immunoreactivity for vimentin and epithelial membrane antigen, whereas the cells of GCF lack the latter determinant and may express muscle-specific actin. Our observations suggest that RM and CM represent closely related developmental malformations; however, RM becomes clinically apparent in a somewhat older patient population than CM and is not associated with major skeletal anomalies as may be found with CM. The distinction between various cutaneous meningothelial proliferations has prognostic importance, as does their separation from GCF. RM and CM are adequately treated by simple excision, whereas GCF, a probable form of fibromatosis, has the potential for local recurrence.

Cutaneous heterotopic meningeal nodules

The clinical, light microscopic and immunohistochemical features of six cutaneous heterotopic meningeal nodules (primary, or type I, cutaneous meningiomas) are described. These are rare lesions of the scalp and back which generally present at birth or in childhood. They appear as small subcutaneous fibrous nodules, with no specific clinical features although they can be associated with abnormalities of spinal closure. Microscopically, they show a variable architecture but have similar cytological features. Important diagnostic features include psammoma and small collagenous bodies. An intimate relationship to nerves is seen in some cases, and this may be of significance with regard to the development of these lesions. As with intracranial meningiomas, there is widespread vimentin expression, and most cases show epithelial membrane antigen expression.

Rudimentary meningocele: a variant of "primary cutaneous meningioma"

We studied 5 primary cutaneous meningiomas. All were congenital. Four were nodules or plaques on the scalp, and one was a lumbar polyp. Two were alopecic. A skull defect was present deep to one lesion, and the lumbar polyp was attached to dura. The tumors were concentrated in the subcutis, where strands of meningocytes were embedded in dense collageous tissue. Meningocytes wrapped around collagenous fibers, producing "collagen bodies". These formed the nidus for calcification that included psammoma bodies. Meningocytes also dissected between collagenous fibers, creating anastomosing spaces that mimicked a vascular tumor. Meningothelial-lined clefts, several milimeters in length, were present in 4 cases. Two lesions extended through dermal defects into the superficial dermis, where adnexa were reduced or absent. The meningocytes contained vimentin and epithelial membrane antigen. They lacked cytokeratin, S100 protein, and endothelial markers. The meningothelial lesions described herein lack the nodular and sheet-like growth patterns that typify meningiomas of the central nervous system and most primary ectopic meningiomas, including some that develop within the skin. They appear closely related to meningoceles and should be viewed as developmental abnormalities rather than neoplasms. The term "rudimentary meningocele" seems appropriate for these lesions.