Cutaneous Meningioma: A Cytomorphological Diagnosis

Humps and bumps of head: review of meningiomas of the scalp

Meningiomas are a type of tumor that arises from meningothelial cells and primarily develops in intracranial space, being some of the most common benign tumors of the central nervous system. However, meningiomas can rarely occur on the scalp and are called primary cutaneous meningiomas. Since the pathogenesis of these lesions is still uncertain, these tumors still pose challenges in terms of histopathological diagnosis. In this review, we will discuss the main cases of scalp meningiomas in the literature, their classification, pathological and immunohistochemical diagnosis, differential diagnosis with other scalp lesions and the most effective treatment. This study highlights the importance of immunohistochemistry in the differential diagnosis of skin lesions located on the scalp.

CT features of primary pleural gritty meningioma: A case report and review of the literature

Primary ectopic meningiomas, although widely reported in multiple sites of the body, are particularly rare in the pleura. Here, we report a 35-year-old asymptomatic woman who was found to have a large mass in the right pleural area on physical examination chest radiography. Chest CT scan showed a large irregular mass from the right second anterior costal pleura to the right supradiaphragm, in which calcified plaques of varying sizes were widely and heterogeneously distributed. The mass was connected to the pleura (anterior rib pleura, mediastinal pleura, diaphragmatic pleura) in a wide base, with oblique "Z" changes in the coronal view. After the contrast agent injection, the mass exhibited mild enhancement on both arterial and venous phase scans. Furthermore, a linear enhancement that was indicative of "pleural tail sign" changes in the pleura adjacent to the mass was observed. The disease was preoperatively misdiagnosed as malignant pleural mesothelioma, and the postoperative pathological diagnosis was right pleural meningioma (gritty type). Therefore, we carefully analyzed its imaging features and differential diagnosis by consulting relevant literature.

Primary ectopic meningiomas: Report of 6 cases with emphasis on atypical morphology and exploratory immunohistochemistry

AIMS

To investigate the histological and immunohistochemical features of primary ectopic meningiomas (PEMs), especially those of primary ectopic atypical meningiomas (PEAMs).

METHODS AND RESULTS

We examined 6 cases of PEM, including 2 PEAM cases, which occurred separately in left nasal cavity, left lower lung, right neck, left orbit, right upper lung, and left upper lung by histological and immunohistochemical analysis. In general, of the 6 PEM cases analyzed, 4 cases exhibited morphology of Grade Ⅰ, including 1 fibrous, 1 meningothelial, and 2 transitional variant. The remaining 2 cases shared similar atypical morphology of Grade Ⅱ. The tumors were distributed in sheet-like patterns with loss of architecture of classic meningiomas. Significant hypercellularity, multi-focal necrosis, and thin-walled blood vessels were identified. The mitotic figures were estimated at 6 per 10 high-power fields in one case, and 8 mitotic figures in another. Immunohistochemically, the 6 PEM cases were all positive for Vimentin and EMA, while none showed immunostaining for CKpan, S-100, CD34, STAT6, SMA, Syn or Bcl-2. 4 PEM cases of Grade Ⅰ were immunoreactive for PR but negative for P53, while the 2 PEAM cases displayed negative staining for PR but positivity for P53. As for Ki-67, the positive staining of 4 Grade Ⅰ cases was no greater than 2%, while the positive rates of the 2 PEAM cases were 10% and 20%.

CONCLUSIONS

Our study has expanded cases of PEMs, especially the 2 PEAM cases in rare sites. Our study has also further summarized the pathological features of PEMs, focusing on the histological features of PEAMs, and the immunohistochemical features worthy of further investigations.

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.

Co-expression of CD34 and h-caldesmon in a benign meningioma-like dermal neoplasm, a case report

Meningioma-like dermal tumor with diffuse coexpression of CD34 and hcaldesmon is rarely reported. Herein, we report a case of a 58-years-old woman who complained of a solitary dome-shaped papule on the left hand. An ellipse of skin measuring 1 x 0.5 x 0.5 cm was excised and sent for histopathological evaluation. Upon sectioning, the specimen showed a whitish firm dermal nodule measuring 3 mm in its greatest dimension. Microscopic examination revealed a well-circumscribed barely encapsulated dermal lesion showing compact round whorled sheets formed of round to ovoid uniform cells with abundant pink cytoplasm. Occasional intranuclear vacuoles were seen. A minor capillary-sized vascular component was seen in the background. Immunohistochemical (IHC) study revealed a diffuse positivity of tumor cells to CD34 and h-caldesmon along with faint reaction to Smooth Muscle Actin (SMA) and ER. However, Desmin, S100, HMB45, EMA, Pan Cytokeratin, and Chromogranin were all negative. Ki67 was very low (1%). The main differential diagnoses of the current lesion are meningioma and glomus family tumors. While the current lesion is morphologically reminiscent of cutaneous meningioma; neither the location nor the IHC stains support that diagnosis. The glomus family is highly suggestive. However, the location, the compact nature of the proliferation, and the positivity of CD34, all are unusual in such entities.

A contemporary and a historical patient with an ectopic meningioma

Introduction: Ectopic meningiomas are rare tumors which can be encountered by all surgical specialties. Patients and methods: We report on two different cases, a contemporary one and a historical one, highlighting the diversity of clinical presentations and prognoses of these lesions. Furthermore epidemiological aspects, clinical features, and diagnostic and therapeutic work-up in patients with an ectopic meningioma are reviewed. Results: Typically, ectopic meningiomas present as gradually expanding lesions, causing a variety of symptoms by their mass effect. Diagnosis is based on histological characteristics, which are similar to those of intracranial meningiomas. Treatment is primarily surgical. Conclusions: The cases we report are at different ends of the clinical and prognostic spectrum. Therapeutic options for different clinical scenarios are discussed.