Cutaneous meningioma

Posttraumatic Cutaneous Meningioma with a "Meningiolipoma" Pattern Presenting as a Nasal Bridge Mass

Meningiomas are tumors originating from arachnoid meningothelial cells. Occasionally, meningiomas are identified outside the central nervous system, and are referred to as extracranial meningiomas (EMs). The vast majority of EMs are an extension from an intracranial or intraspinal tumor. However, primary EMs may arise from extracranial sites with the most common sites being the skin and scalp subcutis, which are further categorized as cutaneous meningiomas (CMs). CMs are rare cutaneous tumors with similar ultrastructural and cytologic findings compared to those of intracranial meningiomas, but with a wide range of histologic differences. Therefore, an assessment using a panel of investigative tools, including imaging, histopathology, and immunohistochemistry, is required to determine the diagnosis of CMs. Here, we report the case of a 64-year-old gentleman presenting with a posttraumatic well-circumscribed superficial mass overlying the right nasal bridge. We are unable to identify other cases arising in the nasal bridge.

Extracranial Meningioma in the Scalp with Concurrent Steatocystoma

This report documents a rare case of an extracranial meningioma on the posterior scalp without apparent dural connection. Additionally, a sebaceous steatocystoma of the anterior scalp presented alongside the meningioma. A steatocystoma localized to the scalp is also remarkably rare. To our knowledge, this is the first report documenting both an extracranial meningioma and a steatocystoma presenting concurrently on the scalp. A male patient in his thirties presented with a mass lesion on the scalp. A CT scan revealed one posterior scalp mass with no intracranial abnormalities. Post excision histologic examination confirmed an extracranial meningioma (meningothelial variant, WHO Grade I). A second anterior scalp mass, not revealed by CT scan, was discovered during surgery. It was excised and diagnosed as a steatocystoma. Meningiomas predominantly occur intracranially but, in some instances, may present as a standalone extracranial tumor without intracranial abnormalities. Because extracranial meningioma is uncommon, it may be overlooked during clinical diagnosis of scalp masses. We recommend that this neoplasm be routinely considered in the differential diagnosis of extracranial tumors. The discovery of another rare tumor—a steatocystoma located in immediate proximity on the scalp—is further remarkable. We briefly review relevant case reports and etiologies and consider a potential relationship between the two neoplasms. However, it remains more likely that the concurrence of these tumors in our patient was simply coincidental.

Epithelioid Cutaneous Mesenchymal Neoplasms: A Practical Diagnostic Approach

Epithelioid cells are rounded or polygonal cells with abundant eosinophilic or clear cytoplasm and ovoid to round nuclei, superficially resembling epithelial cells. Cutaneous mesenchymal neoplasms composed predominantly or exclusively of epithelioid cells are relatively uncommon and can cause considerable diagnostic difficulties due to overlapping histologic features among heterogeneous groups of tumors. Familiarity with practical diagnostic approaches and recognition of key histopathologic features are important for correct diagnosis and management. This review summarizes the histologic features of epithelioid cutaneous mesenchymal neoplasms and discusses their differential diagnoses from malignant melanomas and carcinomas.

Meningioma-like Tumor of the Skin Revisited: A Distinct CD34+ Dermal Tumor With an Expanded Histologic Spectrum

The term meningioma-like tumor of the skin (MLTS) was coined in 1993 to designate a particular whorled spindle cell superficial cutaneous tumor. No additional confirmed cases of this entity have been reported to date. Some authors have speculated that these cases might be cellular neurothekeomas. In order to delineate the histologic spectrum and the immunophenotype of this unusual tumor, we studied 5 cases, 2 previously unreported and the 3 original cases. The immunohistochemical findings of case 5, however, were limited to those from the original study. Clinically, the tumor presented as a reddish papule, plaque, or nodule, located in the extremities or trunk. The patient often referred to a recent growth of a longstanding lesion. Histologically, the characteristic whorled spindle and stellate dendritic cell population, commonly in a perivascular arrangement, and variable myxoid component, were consistently found in all cases. A prominent microvasculature was also a constant finding. The presence of large deciduoid cells was conspicuous in one case. A reticular pattern of multivacuolated cells giving a chordoma-like appearance was evident in another case. Tumor cells were diffusely positive for CD34 in all 4 cases studied, and negative for S-100, EMA, NKI-C3, CD68, and smooth muscle markers. No complete loss of retinoblastoma protein was found. No brachyury immunostaining was found in the case with chordoid features. No EWSR1 or NAB2-STAT6 gene fusions were found. From these findings, we demonstrate that MLTS is a distinct CD34 spindle cell benign dermal tumor, unrelated to cellular neurothekeoma, and exhibiting myxoid, deciduoid, or chordoma-like features.

Rudimentary Meningocele of the Scalp: A Pitfall in the Diagnosis of Vascular Neoplasms

We present a case of sequestrated meningocele in a 1-year-old girl, who presented with a 1x1cm occipital swelling since birth. CT brain revealed the soft tissue swelling to be extracranial. She underwent surgical excision of the specimen and the excised mass was sent for histopathological examination. The specimen consisted of skin and subcutaneous tissue measuring 2 x 1 x 1 cm. The entire tissue was paraffin processed. Multiple sections studied from the lesion showed an ill circumscribed locally infiltrative dermal lesion. The lesion was composed of whorled proliferations of meningothelial cells enclosing pseudovascular spaces. Immunohistochemically the lesion was positive for EMA, Desmin, and negative for endothelial markers. The present case was documented as a rare case of a rudimentary meningocele.

Hamartomas of skin and soft tissue

Hamartomas are benign lesions composed of aberrant disorganized growth of mature tissues. Choristomas are similar, except that they are composed of tissues not normally found at the anatomic site in which the lesion is arising. A wide range of hamartomas and choristomas can arise in the skin and soft tissue. Some of these may cause diagnostic difficulty and potentially be mistaken for neoplasms. Some neoplasms may resemble hamaratomas. Here we review the current clinical and pathologic features of these lesions, both common and rare, and discuss how to distinguish them from other entities in the differential diagnosis.

Primary Type I Cutaneous Meningioma of the Scalp: Cytohistological and Immunohistochemical Features of a Rare Neoplasm

Primary cutaneous meningioma of scalp is a rare lesion and often clinically misdiagnosed. As clinical features are nonspecific, the diagnosis is often perplexing in this exceptional site. We report a case of a 7-year-old girl presenting with a nodule over occipital region of scalp since birth. No bony defect was noted on X-ray. On fine needle aspiration cytology, smears were cellular consisting mostly cohesive clusters of cells having pale pink granular cytoplasm, round to oval nuclei with unassuming nucleoli along with psammomatous calcification suggestive of cutaneous meningioma. Histology and immunohistochemistry with epithelial membrane antigen (EMA) confirmed the diagnosis. Histological sections revealed a proliferation of a spindle-shaped cell in the dermis, arranged in whorls or individually amid collagen fibers and psammoma bodies. Immunohistochemical study revealed positivity for EMA. A diagnosis of Type I cutaneous meningioma was finally rendered based on characteristic clinical, intraoperative, morphological, and immunohistochemical observations.

Cutaneous Meningioma: A Cytomorphological Diagnosis

Cutaneous meningiomas are rare tumors. These are ectopic meningothelial cells located in the dermis and subcutis, and are usually seen on the scalp. Here, we report the case of a 40-year-old woman who presented with a slowly growing asymptomatic mass over the scalp in the right parieto-occipital region. The lesion was firm, adherent to underlying structures, and covered by normal appearing skin. The cytomorphological features along with histological and immunohistochemical studies showing positivity for epithelial membrane antigen, Vimentin, and S100 helped in making a definitive diagnosis of cutaneous meningioma. No evidence of intracranial meningioma was noted in contrast-enhanced computed tomography of the brain.

Recurrent meningioma of the scalp after 13 years

Meningiomas represent some of the most common types of tumour of the central nervous system. They are considered benign, with ∼1 in 1000 known to metastasise. We report a case of recurrent meningioma of the scalp 13 years following craniotomy to treat the primary. The recurrent tumour of the scalp was eventually excised 5 years later and the defect closed with an anterolateral thigh free flap in a joint procedure between the neurosurgeons and plastic surgeons. Histology of the scalp lesion confirmed a WHO grade I meningioma. Although a number of explanations for recurrent scalp meningiomas exist, the precise role of isolated genetic defects in scalp meningiomas is incomplete. The scalp meningioma in this case consisted of a complex karyotype suggestive of more aggressive disease. This case emphasises that cytogenetics may play a greater role in identifying more aggressive tumours than histology alone.

Frontal cutaneous meningioma--Case report

Cutaneous meningiomas are rare tumors most commonly located on the scalp. We report the case of a 55-year-old male who presented with a 2 x 3 cm tumoral lesion on the forehead. The lesion was hard, adherent and covered by normal skin. Incisional biopsy revealed a proliferation of monomorphic round cells, organized in nests and focally forming pseudovascular spaces. Immunohistochemical study revealed positivity for epithelial antigen membrane and vimentin. Vascular markers, cytokeratins and S100 protein were negative. A brain CT scan did not show any evidence of intracranial meningioma. The authors describe the case of a cutaneous frontal meningioma in probable relation with previous cranioencephalic trauma.

Meningioma presenting as temporal region swelling: Diagnosis by cytopathology and immunohistochemical confirmation on cell block preparation

Meningiomas are common intracranial neoplasms. Meningomas are rarely subjected to fine-needle aspiration (FNA) studies. However, intraoperative squash preparations are commonly done. FNA of meningiomas are usually performed incidentally for cases with a clinical suspicion of some other disease such as metastatic carcinoma. We are reporting two cases, which were referred to our center with a diagnosis of metastatic carcinoma on FNA from swelling of the temporal region. We are discussing the characteristic cytomorphological features, which help in diagnosing meningiomas, the common cytological differentials, and the utility of immunohistochemistry (IHC) on cell block preparations in confirming the diagnosis, especially when there is a clinical differential diagnosis.

Periocular extracranial cutaneous meningiomas in two dogs

Cutaneous meningiomas are rare tumors in human beings and animals. Two canine cases of cutaneous meningiomas affecting the eyelid are described in the current study: the first from a 5-week-old female Springer Spaniel dog with an 8 cm in diameter congenital mass expanding the left upper eyelid and medial canthus; the second from a 10-year-old female spayed Maltese-Poodle mix dog with 3 firm subcutaneous nodules affecting the right upper eyelid. All masses were removed surgically. Histologically, tumors were composed of spindle-to-epithelioid cells arranged in small lobules forming solid concentric whorls. Neoplastic cells were positive for vimentin and S100 and negative for pancytokeratin, glial fibrillar acid protein, and neurofilament. Transmission electron microscopy revealed meningothelial cells with convoluted interdigitating processes, desmosomes, and hemidesmosomes, and moderate numbers of cytoplasmic microfilaments. None of the cases presented a primary neuroaxial meningioma. The first case presents clinicopathological features consistent with human type I (congenital) cutaneous meningioma. The second case is consistent with a type II (acquired ectopic) tumor, and both are hypothesized to arise from ectopic arachnoid cells displaced during development.

Cytopathology of extracranial ectopic and metastatic meningiomas

INTRODUCTION

Extracranial meningiomas may infrequently be encountered as ectopic or metastatic tumors. Their rarity and unique cytomorphology often pose significant diagnostic dilemmas. The aim of this study was to report our experience with a series of ectopic and metastatic meningiomas, characterizing their cytomorphology with histological correlation.

MATERIALS AND METHODS

A retrospective analysis involving 13 patients with cytological preparations from extracranial meningiomas was performed. Cytology cases were correlated with available surgical resection specimens. Data regarding clinical findings, tumor information, cytomorphology, follow-up histological features and immunohistochemistry were recorded and analyzed.

RESULTS

There were 5 cases with metastases and 8 ectopic meningiomas. Metastases occurred in the scalp/skull, lung, paraspinal soft tissue and liver. Primary ectopic meningiomas were located in the paranasal sinuses and ear, orbit and neck. Cytomorphological features characteristic of meningiomas were identified in the majority of samples including tightly cohesive clusters of spindled cells, whorls, intranuclear inclusions, nuclear grooves and psammomatous calcification. Unusual cytomorphological features identified in only a few cases included epithelioid cell predominance, abundant inflammatory cells, small-cell change, papillary structures and pseudoacinar growth. Metastatic tumors exhibited more nuclear atypia and occasionally mitoses or necrosis. Meningiomas were shown to be immunoreactive for epithelial membrane antigen, pancytokeratin and vimentin.

CONCLUSION

Although rare, extracranial meningiomas can be encountered in cytologic specimens and should be included in the differential diagnosis when characteristic morphological features of meningiomas are seen. Cytopathologists should be aware that these lesions could be mistaken for other tumors, especially when confounded by atypia and unusual cytomorphological features.