Isolated Ectopic Cutaneous Atypical Meningioma of the Scalp: Another Mimicker of Primary Adnexal Tumor

Recurrent subcutaneous metastasis of a convexity meningioma: a case report and literature review

Subcutaneous metastasis in the operative route after intracranial meningioma resection is extremely rare. Here we describe the case of a 69-year-old male who was operated on in our department for a convexity meningioma that spread a few years after surgery in the soft tissues next to the craniotomy site. Twenty-one other cases have been found in the medical literature. In this article, we discuss mechanisms of growth, presentation and management of subcutaneous meningiomas.

Aplasia Cutis Congenita With Cutaneous Meningioma: A Rare Case

ABSTRACT

Cutaneous meningioma, characterized by ectopic meningothelial cells in the dermis or subcutis, is a rare neoplasm. Generally, the most common location for cutaneous meningioma is the scalp. We report a case of cutaneous meningioma presenting as soft, light red, atrophic, and smooth patches with central blue spots. On histological examination, the tumor consisted largely of epithelioid cells, whorls, nests, and syncytial sheets of meningothelial cells. HMB-45, Melan-A, and S100 were negative; epithelial membrane antigen and somatostatin receptor 2 were positive. Ultimately, histopathologic examination and immunohistochemistry results supported a diagnosis of cutaneous meningioma. In addition, dermal dysplasia was observed above the tumor, manifested by thinning of the dermis and loss of appendages. No abnormalities were found on brain magnetic resonance imaging. Cutaneous meningioma is an extremely rare tumor, and its manifestation as an atrophic patch is even rarer. There have been mainly clinical reports of cutaneous meningioma. This was a rare case of focal aplasia cutis congenita with cutaneous meningioma. For cutaneous meningioma to be diagnosed earlier, there needs to be greater public awareness about the condition.

Type III Cutaneous Atypical Meningioma of the Scalp

Cutaneous meningiomas can be a diagnostic challenge, as they are not only found very rarely in extracranial sites, including the skin, but also because of the histopathologic overlap with several other spindle cell tumors. Cutaneous meningiomas are divided into type I (congenital), type II (ectopic) and type III (via a direct extension) lesions. We present a rare case of atypical meningioma of the skin in a 71-year-old female. A patient presented with a painful and enlarging lesion on the left central frontal scalp. Biopsy showed bone and soft tissue with involvement of a spindle cell neoplasm, consisting of whorled nests with atypical features, including variably increased mitotic index, areas of hypercellularity, and sheeted architecture. The overall findings were consistent with an atypical meningioma (WHO grade 2). Atypical meningiomas constitute only 5 - 15% of all meningiomas. A skull MRI was later performed, which demonstrated a left frontal tumor consistent with an atypical meningioma that had eroded through the skull. Dermatopathologists should consider cutaneous meningioma as a differential diagnosis of spindle cell neoplasms of the skin and subcutaneous tissue in head and neck. This article is protected by copyright. All rights reserved.