Meningothelial Elements Research Articles

Angiomatous meningioma: A rare case report

Angiomatous meningioma is a rare subtype of meningioma that accounts for 2.1-2.59% of all meningiomas. Microscopically, it shows numerous vascular spaces in addition to the normal meningothelial elements. Here, we are presenting a case of 41 years old female who presented with history of bilateral loss of vision, headache, loss of consciousness, seizures, giddiness and vomiting and was diagnosed as angiomatous meningioma on histopathological examination. Despite the availability of neuroimaging diagnostic modalities, histological examination and immunohistochemistry remain the gold standard for final diagnosis.

Type I cutaneous meningioma of dorsal thoracic spine (Rudimentary Meningocele): A rare entity at an unusual site

Cutaneous meningiomas (CM) are rare variants of meningiomas which are further classified into three subtypes. Type I CM (TICM) or Rudimentary meningocele (RM) is an uncommon developmental anomaly in which meningothelial elements are displaced into the skin and soft tissue. We present a case of 11 year boy with an upper back swelling since early childhood. His MRI spine showed a lesion at T4-T7 level with a fistulous tract connecting it to dural sac. Histopathology revealed clusters of oval to spindle cells arranged in whorls amidst collagen bundles and psammoma bodies. On immunohistochemistry these cells expressed EMA and Vimentin. A diagnosis of TICM was rendered based on these characteristic clinico-radiological & histopathological features. TICM pose a diagnostic challenge clinically and histopathologically and have an excellent prognosis. This is the 4 Indian case of RM and the 1 case of RM to be located in the spine in the Indian literature.

THE “-OMAS” and “-OPIAS”: Targeted and Philosophical Considerations Regarding Hamartomas, Choristomas, Teratomas, Ectopias, and Heterotopias in Pediatric Otorhinolaryngologic Pathology

The spectrum of "developmental" lesions that occur in the head and neck predominantly congenital in origin and arising at birth and/or discovered in childhood is broad and fascinating. These have been grouped into categories such as "ectopias", "heterotopias", "hamartomas", and "choristomas". On a philosophical and consequently systematic level, these lesions, mostly benign tumors seem to lack a true understanding of the pathogenetic foundation on which to base a more unified taxonomic designation. In this review, we will consider some of these select tumors as they represent syndromic associations (nasal chondromesenchymal hamartoma and DICER1 syndrome), the lingual choristoma from the perspective of its nomenclature and classification, lesions with ectopic meningothelial elements, and teratomas and the enigmatic "hairy polyp" in reference to a broader discussion of pathogenesis and pluripotent cells in the head and neck. A consistent thread will be how these lesions are designated with some final thoughts on future directions regarding the investigation of their pathogenesis and taxonomic nomenclature.

Cutaneous Heterotopic Brain Tissue (Neuroglial Choristoma) with Dysplastic Features in a Kitten

A 3-month-old, male European shorthair kitten exhibited an ill-defined, soft mass on the skin of the frontal head, which was present since birth. The surgically resected tissue was representative of a discrete dermal and subcutaneous mass comprising islands of neurons, glial and meningothelial elements, sometimes atypical or dysplastic, separated by dense collagenous connective tissue. There was no evident connection between this tissue and the brain. Immunohistochemical examination confirmed the presence of neurons and a pleocellular glial population, supporting a diagnosis of cutaneous neuroglial choristoma believed to be secondary to sequestered (resolved) meningoencephalocoele. Ectopic brain tissue is very rare in small animals. Some atypical features displayed by this tissue may be misdiagnosed as neoplasia. Communication between surgeon and pathologist to clarify the relationship of the lesion to surrounding structures is helpful to avoid misdiagnosis.

Rudimentary Myelomeningocele: A Rare Case Report and Literature Review

Rudimentary meningocele, in which meningothelial elements occupy most of a solid skin-covered mass, is extremely rare. Most reported rudimentary meningocele were on the midline scalp, preferentially involving the occiput and vertex. A 10 yearold child who presented with rudimentary myelomeningocele in the midline at the level of T7-T8 is reported. We believe this is the first reported case of a rudimentary myelomeningocele at this site.Journal of Nepalgunj Medical College Vol.12(1) 2014: 39-40

Sequestrated meningocoele within a naevus sebaceous of Jadassohn on the scalp of a child

Sequestrated meningocoele is an uncommon developmental anomaly in which meningothelial elements are found in the skin or subcutaneous tissue without underlying bony defect. By contrast, naevus sebaceous of Jadassohn (NSJ) is a circumscribed hamartomatous lesion occurring in about 0.3% of newborns. We report a child with a histologically confirmed sequestrated meningocoele within an NSJ on his scalp vertex. Such an occurrence has not been reported previously.

Meningothelial Hamartoma Associated with Nevus Sebaceus

Meningothelial hamartoma is a rare lesion of ectopic meningothelial elements that usually presents on the scalp at birth or in early childhood. The characteristic spindle cells infiltrate through collagen and stain positively for epithelial membrane antigen and vimentin but are negative for CD31 and CD34. This distinguishes meningothelial hamartoma from vascular tumors. Nevus sebaceus is a fairly common lesion that has been associated with several different benign tumors, including trichoblastoma and syringocystadenoma papilliferum. We describe the case of a 17-month-old girl who presented with a meningothelial hamartoma in association with a nevus sebaceus. To the best of our knowledge, this is the second case reported.

Lymphoplasmacyte-rich meningioma: a case report of a rare neoplasm

Lymphoplasmacyte-rich meningioma (LPM) is a rare variant of meningioma, which is characterized by massive inflammatory cell infiltration and rare meningothelial elements. The authors report the clinicopathological features of a LPM located at the right parietal convexity in a patient with generalized tonic-clonic seizures and paresthesia in the left arm. The surgical specimen consisted of a gray nodule measuring 3.5 × 3 × 1.8 cm. At microscopy, a few epithelioid cells associated with numerous lymphocytes/plasma cells were identified. Positive immunoexpression for epithelial membrane antigen (EMA) and progesterone receptor was found in the epithelioid cells, and positive staining for CD3, CD5 and CD20 in the inflammatory cells. Thus, the diagnosis of LPM was established.

Malignant Meningiomas With Epithelial (Adenocarcinoma-Like) Metaplasia: A Study of 3 Cases

Meningiomas exhibit a wide range of histomorphologic features, including variable mesenchymal and epithelioid phenotypes. Meningiomas also represent the most common host tumors for systemic metastases, particularly carcinomas. Recently, however, 3 unique dural-based neoplasms were encountered, wherein malignant-appearing gland-like structures were intermixed with meningothelial elements, yet genetic data suggested epithelial metaplasia rather than metastatic carcinoma. To describe and characterize a rare meningioma pattern with potential diagnostic pitfalls. In addition to routine clinical, radiologic, and histopathological analyses, cases were studied with immunohistochemistry and fluorescence in situ hybridization (FISH) to elucidate the origins of 2 seemingly disparate tumoral components. Immunohistochemistry confirmed an epithelial ontogeny of gland-like structures, with extensive CK7 positivity suggesting possible lung or breast primaries. However, identical losses of chromosomes 1p, 14q, and 22q in meningothelial and epithelial components were identified by FISH, an observation consistent with a monoclonal derivation and supporting the diagnosis of malignant meningioma with adenocarcinoma-like metaplasia. Although this phenomenon was reminiscent of gland-like metaplasia in secretory meningioma, it differed in that the gland-forming cells were cytologically malignant, formed extracellular rather than intracellular lumina, and were unassociated with pseudopsammoma bodies. Nevertheless, intermingled secretory and adenocarcinoma-like features were seen in one case, suggesting some relationship between these 2 forms of epithelial metaplasia. Recognition of adenocarcinoma-like metaplasia in meningiomas can prevent a misdiagnosis of metastatic carcinoma, with all its associated implications for patient management.

Case Report: Meningothelial Hamartoma of the Scalp in a 9‐Year‐Old Child

Meningothelial hamartomas represent a collection of meningothelial elements in an ectopic location. Lesions are histologically characterized as a proliferation of connective tissue elements and small- and medium-sized vessels admixed with meningothelial elements. Lesions are most often located on the scalp, present at birth, and do not extend past the subcutis. We discuss the case of a 9-year-old African American girl presenting with one such lesion on the parietal aspect of the scalp.

Anaplastic Meningioma Arising From a Radiologically Diagnosed Arachnoid Cyst

We report the first example of an anaplastic meningioma arising from an intracranial arachnoid cyst and discuss the diagnostic challenges of this case, including the useful role of genetic markers. A 72-year-old man presented with transient episodes of expressive dysphasia and focal motor seizures, superimposed on a 6-month history of worsening headaches and dizziness. His past history was significant for a previously drained left-sided chronic subdural hematoma and a radiologically diagnosed left middle fossa arachnoid cyst. Magnetic resonance imaging on admission showed variable wall thickening of the arachnoid cyst with mild mass effect on the left frontotemporal lobes. The patient underwent decompression of the arachnoid cyst and biopsy of the cyst wall. Histologic and immunohistochemical studies of the thickened portion initially suggested a metastatic carcinosarcoma, but fluorescence in situ hybridization (FISH) studies confirmed the diagnosis of anaplastic meningioma based on characteristic chromosomal deletions. The patient returned 2 months later with progressive disease, leading to his death 6 weeks later despite repeat surgery for tumor debulking. Malignant transformation of meningothelial elements in arachnoid cysts is an exceptionally rare complication that poses considerable diagnostic challenges. Genetic markers may be particularly helpful in such cases.

Rare growth of a psammomatous meningioma in a mature ovarian Teratoma: A case report

The presence of meningothelial elements along with abundant psammoma bodies indicates the presence of a benign meningioma within a teratoma. Recognition of meningioma arising in the setting of a teratoma is of prognostic significance, depending on the nature of this component and its spread beyond the organ of origin. We report a case of psammomatous meningioma in which meningothelial cells and psammoma bodies were both abundant and diffuse, allowing for the diagnosis of a meningioma.

Angiomatous meningioma: A diagnostic dilemma

Angiomatous meningioma accounts for 2.1% of all meningiomas. It has features of a typical benign meningioma with many small or large vascular channels which may predominate over its meningothelial elements. We present here a series of three cases of angiomatous meningioma, which posed diagnostic difficulty to clinicians, radiologists, and pathologists. All the three cases showed a tumor entirely composed of thin-walled vascular channels and cells with bland morphology in the background. The diagnosis was confirmed by immunohistochemistry. We present series of three cases to highlight the histomorphological features of this uncommon variant of meningioma that could help in distinguishing it from hemangioblastoma and hemangiopericytoma.

Congenital Hamartoma of the Scalp With Meningothelial, Sebaceus, Muscular, and Immature Glandular Components

A 4-month-old boy presented with a congenital, solitary, yellowish-red, eroded tumor on the scalp, histologically characterized by an ectopic proliferation of vascular and meningothelial elements intimately admixed with mature connective-tissue elements, adipose tissue, and smooth-muscular fibers. In addition, the presence of characteristic histopathological features of a nevus sebaceus and areas with immature glandular differentiation were observed. The diagnosis of a congenital hamartoma of the scalp with meningothelial, sebaceus, immature glandular, and muscular components was established. We review the heterogeneous group of cutaneous lesions with meningothelial elements and their pathogenesis.

Ectopic Meningothelial Hamartoma of the Scalp

A 7‐month‐old male infant presented with a 2 month history of a solitary, well circumscribed, 1.2 cm right parietal scalp lesion. An MRI excluded intracranial extension of the lesion. Grossly the excised lesion was tan‐grey, soft to rubbery with focal areas of hemorrhage. On histology, the lesion demonstrated elongated strands of haphazardly arranged fibrous tissue and meningothelial elements with clusters of plump, cuboidal epitheloid cells extending along connective tissue planes in the dermis and subcutaneous tissue. The meningothelial elements were intimately admixed with mature adipose tissue and proliferation of small to medium sized vessels. The overlying epidermis was unremarkable. No mitotic figures or areas of necrosis were identified. The meningothelial cells were positive for Vimentin and Epithelial Membrane Antigen. S‐100 protein was negative and CD‐34 was positive only in the endothelial cells. The gross, histologic and immunohistochemical features are consistent with ectopic meningothelial hamartoma of the scalp. The meningothelial elements characteristic of this entity are believed to arise from displaced, ectopic meningothelial rests in the scalp and are thus regarded as simply representing a proliferation of the hamartomatous process.

Meningothelial hamartoma of the scalp: two case reports and literature review

Meningothelial hamartomas are rare congenital scalp lesions composed of an admixture of cells including the meningothelial cell type. Histologically they are characterized as lesions with proliferative connective tissue, epitheloid cells forming interanastamosing vascular channels, and meningothelial elements. Lopez first described these lesions in 1974 and since that time a total of 32 cases have been reported [3]. In previous reports, they have been referred to as hamartomas with ectopic meningothelial elements, sequestered or rudimentary meningocele, and ectopic meningioma [1, 3, 5]. Two additional cases of meningothelial hamartomas are discussed as to their clinical presentation, work up, pathological findings at excision, and outcome. A persistent connection with the central nervous system remains a primary concern and mandates adequate preoperative testing to exclude this possibility.

Oropharyngeal hairy polyp with meningothelial elements

The so-called hairy or teratoid polyp is a rare lesion of bigerminal origin that comprises elements derived from both ectodermal and mesodermal cell lines. In this article we report the presence of meningothelial elements in a hairy polyp, a previously undescribed component of this entity. The lesion was characterized by a pedunculated outgrowth from the hard palate. The surface of the outgrowth was covered by squamous epithelium and a central core of fibroadipose tissue, pilosebaceous glands, cleftlike pseudovascular spaces, and groups of epithelioid cells. These reticulated and cellular foci had the immunohistochemical and ultrastructural features of meningothelial tissue.

Rudimentary Meningocele Presenting With a Scalp Hair Tuft

Rudimentary meningoceles represent a developmental anomaly in which meningothelial elements are found in the skin. The majority of rudimentary meningoceles occur on the scalp over the occiput or along cranial suture lines. They are usually recognized at birth and present as a pink papule or nodule or an area of alopecia. We present two patients who presented with a scalp hair tuft at birth over a rudimentary meningocele. This finding has not been previously reported. Rudimentary meningoceles are uncommon developmental anomalies that are of clinical importance due to the occasional presence of connection to the central nervous system. Due to this potential for central nervous system connection, any midline lesion in an infant, including midline hair tufts, deserves careful preoperative evaluation including imaging studies.

Hamartoma of the Scalp with Ectopic Meningothelial Elements

Five cases of a distinctive benign soft tissue lesion of the scalp in patients ranging from 4 months to 40 years of age are described. Clinically, the lesions appeared as solitary, subcutaneous nodules suggestive of a cystic vascular malformation or other benign condition. Histologically, however, the lesions were characterized by a monotonous, pseudoinfiltrative proliferation of cuboidal epithelioid cells arranged in clusters within the dermis and subcutaneous tissue in intimate association with vessels, adipose tissue, and other connective tissue elements. A prominent feature in all cases was the presence of areas simulating freely anastomosing vascular channels lined by round to spindle-shaped, slightly hyperchromatic epithelioid cells reminiscent of angiosarcoma. Immunohistochemically, these cells were negative for factor VIII-related antigen and Ulex europaeus lectin but were strongly positive with vimentin and epithelial membrane antigen antibodies, this latter being in keeping with the immunohistochemical profile of meningothelial cells. The meningothelial nature of these cells was supported by the electron microscopic demonstration in one case of cells with complex, interdigitating cytoplasmic processes that were joined by scattered cell junctions and contained abundant intracytoplasmic intermediate filaments. The intimate admixture of meningothelial elements with haphazardly arranged connective tissue elements sets these lesions apart from cutaneous meningiomas and warrants their designation as hamartomas with an ectopic meningothelial component.