Cytology of primary pulmonary meningioma. Report of the first multiple case

Primary pulmonary meningioma with associated multiple micronodules: a case report and literature review

Primary pulmonary meningioma (PPM) is a rare and benign slow growing tumor with good prognosis. It often presents as an asymptomatic, well-circumscribed, solitary pulmonary nodule. Wedge resection is the management of choice for both diagnosis and treatment. Here, we report one case of PPM with increased fluorodeoxyglucose (FDG) uptake and associated micronodules, which was clinically suspicious for malignancy. The patient was a 60-year-old female who presented with persistent shortness of breath for 1 year. Chest computed tomography showed a 1.5-cm well-circumscribed homogenous nodule in the left upper lobe with increased FDG uptake and multiple smaller well-circumscribed micronodules scattered in both lungs. Left upper lobe wedge resection confirmed the diagnosis of PPM. PPM can deceptively mimic malignancy, so recognizing this rare entity and including it in the differential diagnoses of pulmonary nodules, especially with avid uptake of FDG, is crucial to avoid misdiagnosis and overtreatment.

Primary pulmonary meningioma: A case report and review of the literature

BACKGROUND

Primary pulmonary meningioma (PPM) is a rare disease that is usually benign. The most common presentation of PPM is isolated pulmonary nodules or masses, so the disease can mimic any other lung tumor on imaging, especially lung cancer or metastasis.

CASE SUMMARY

A 47-year-old asymptomatic woman presented with a well-defined, lobulated pulmonary mass with calcification in the left lower lobe. The mass measured 69 mm × 57 mm × 61 mm and was found during a chest computed tomography (CT) performed for physical examination. Contrast-enhanced CT and positron emission tomography (PET)/CT revealed mild enhancement of the mass, with accumulation of 18-fluoro-2-deoxy-D-glucose (¹⁸F-FDG). Transbronchial biopsy suggested a provisional diagnosis of low-grade neuroendocrine tumor. Subsequent enhanced head magnetic resonance imaging revealed no positive lesions. An open cuff resection of the left lower lobe and wedge resection of the lingual segment were performed. Histopathological and immunohistochemical examination revealed that the mass was a PPM.

CONCLUSION

PPM should be considered in the differential diagnosis of isolated pulmonary masses found incidentally on CT and should be diagnosed based on a combination of radiological and histological features. Surgical resection is currently the main treatment strategy. No recurrence of benign PPMs has been reported after complete resection.

Primary pulmonary meningioma presenting as multiple lung nodules: A case report

Primary pulmonary meningioma (PPM) is a very rare and mostly benign disease. Although PPM is incidentally detected as a solitary pulmonary nodule on X-ray or chest computed tomography, it does not have unique radiological characteristics; thus, it is difficult to differentiate it from other lung tumors. A healthy 54-year-old man visited our hospital because of multiple variable-sized lung nodules. He had no contributive medical history and no abnormality that was suggestive of extrapulmonary malignancy. Video-assisted thoracoscopic wedge resection was undertaken for diagnosis, and the tumor cells were histopathologically confirmed as PPM. Brain magnetic resonance imaging revealed no intracranial tumor. The patient has been well and without any progression of the remaining lesions over 24 months. Here, we present the clinicopathological features of this case in which the patient's nodules were mistaken for multiple metastatic lung nodules.

[A pulmonary tumor that racks our brains!]

We report the case of a 74-year-old woman who, as part of the follow-up for two breast cancers, presented a 2cm long lung nodule. A microscopic examination of the biopsy under a scanner showed a proliferation of epithelial appearance but whose immunophenotypic profile did not permit a precise diagnosis (negativity of CK7, GATA3, TTF1, negative estrogen receptors but positive progesterone receptors). Wedge resection surgery was performed. Extemporaneous and definitive microscopic examination showed a well-defined lesion made up of lobules of cohesive-looking cells, frequently forming coils. The tumor cells showed some intranuclear inclusions and a few psammomas while the immunohistochemical study showed diffuse expression of EMA, SSTR2A and progesterone receptor markers and a low proliferation index. A diagnosis of a pulmonary localization of a meningioma was proposed. The radiological assessment of the entire neuraxis did not show any other lesion leading to the final diagnosis of primary intra-pulmonary meningioma. This is an exceptional tumor with a difficult histopathological diagnosis of biopsy material, which must familiar to the pathologists. It is associated with an excellent prognosis. Our observation aims to illustrate the macroscopic and microscopic aspects and to present the data from the recent literature review.

Primary pulmonary meningiomas: report of two cases and review of the literature

BACKGROUND

Meningiomas rarely occur outside the skull, and primary pulmonary meningiomas (PPMs) are more rare. Only a few cases have been reported in the literature. The clinicopathological characteristics are not clear and it is easy to be misdiagnosed, so it is very important to master its diagnosis and differential diagnosis.

METHODS

We report two women with primary pulmonary meningioma. At the time of physical examination, the small solitary pulmonary nodules were detected on chest radiograph, and wedge resection was performed by Video-assisted Thoracoscope Surgery(VATS), and histologic evaluation showed that the lesions were benign PPMs. The clinicopathological features, immunophenotype and differential diagnosis of PPMs were analyzed, with a review of the cases published in the literature.

RESULTS

The study group comprised of 40 patients, 14 males and 26 females. The median age was 56.5 years (range 18-108). Thirty patients who underwent routine screening studies were asymptomatic but had a pulmonary nodule detected on chest X-ray. Nine patients had respiratory symptoms. Only 1 patient had non-specific symptoms. Most of the PPMs were benign, only 3 cases were malignant. Benign PPMs ranged from 0.6 cm to 6 cm in diameter (median 2 cm). The 3 malignant PPMs were 5 cm, 6.5 cm and 15 cm in diameter. The prognosis of benign PPM resection is good, with almost no recurrence or metastasis. But the two of three malignant PPMs relapsed.

CONCLUSIONS

PPM is very rare. It needs to be diagnosed by combining histology and immunohistochemistry. Diseases that need to be identified include spindle cell mesothelioma, spindle cell thymoma, spindle cell carcinoma, metastatic tumor, etc.

Multiple primary pulmonary meningiomas: 20-year follow-up findings for a first reported case confirming a benign biological nature

INTRODUCTION

Primary pulmonary meningiomas (PPMs) are very rare neoplasms, and we reported the first multiple case of PPMs in 1998. Usually, PPMs are slow-growing tumors with a good prognosis. Herein, we reported a rare multiple case of PPMs with an extremely long clinical course.

PRESENTATION OF THE CASE

An 84-year-old Japanese woman with a history of multiple PPMs histologically confirmed as having a right-sided slowly growing lung nodule for 20 years. In 2010, we also reported the additional clinical course in the initial case 10 years after surgery implying a benign biological nature. Subsequent to that report, new lesions appeared in the bilateral lung fields with quite a slow growth rate. She was asymptomatic, and no tumor was observed in the cranial cavity during the course of her disease.

DISCUSSION AND CONCLUSION

This case illustrates rare multiple PPMs and highlights their biological behavior with very slow progression from a most likely benign tumor over a 20-year period.

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.

Multiple Pulmonary Metastases following Total Removal of a Bilateral Parasagittal Meningioma with Complete Occlusion of the Superior Sagittal Sinus: Report of a Case

Pulmonary metastases of benign meningiomas are extremely rare. The case of a 34-year-old man with bilateral parasagittal meningioma who developed pulmonary metastases is described. The meningioma was an enormous hypervascular tumor with invasion of the superior sagittal sinus. The tumor was resected completely and histologically diagnosed as transitional meningioma. The Ki-67 labeling index was 5%. Four months after operation, the patient subsequently developed bilateral multiple lung lesions later identified as metastases. The lung lesions were partially removed surgically and histologically diagnosed as meningothelial meningioma WHO grade I. The Ki-67 labeling index was 2%. The histological findings demonstrated that the tumor occupied the arterial lumen and the perivascular space, suggesting that pulmonary tumors might metastasize via the vascular route. The histopathological features and mechanisms of metastasizing meningiomas are reviewed and discussed.

Primary pulmonary meningioma: report of a case and review of the literature

Primary pulmonary meningioma (PPM) is a rare disease and usually presents as a solitary pulmonary nodule (SPN). These lesions are mostly benign, but malignant PPMs have been reported, and primary lung cancer or metastasis may be suspected on imaging. We report one case of benign PPM, with a review of 37 cases published in the literature. Diagnostic work-up included radiological chest study and in 3 cases positron emission tomography (PET) showing increased uptake, highly suspicious for malignancy. After exclusion of 13 cases lacking radiological studies of the central nervous system (CNS), 25 patients with radiological data and histological assessment confirming PPM were considered in the analysis. All patients underwent surgical resection except for 1 case with diagnosis at autopsy. Histological assessment revealed benign PPMs in 23 cases (including all 3 cases with positive PET) and malignant PPMs in 2 cases. No recurrence was observed in long-term follow-up of patients with benign PPMs, but the two malignant PPMs relapsed. PPM is an uncommon SPN, so that it can be misdiagnosed and its management unsuited. Indeed, 8 patients (32%) were overtreated with major thoracic surgical resection or with chemotherapy. When feasible, pulmonary wedge resection by video-assisted thoracic surgery (VATS) including intra-operative histological examination is the most suitable approach to determine the diagnosis and the volume of pulmonary resection.

Primary chordoid meningioma of lung

Primary meningiomas of the lung are rare. Most pulmonary meningiomas are typical syncytial or transitional meningiomas with smaller numbers of fibrous-type tumors. Herein, we report an unusual pulmonary tumor with the microscopic, immunohistochemical, and ultrastructural characteristics of a chordoid meningioma. The tumor was composed of cords and fascicles of small- to medium-sized spindle and epithelioid cells with eosinophilic cytoplasm and round nuclei with finely dispersed chromatin. The tumor cells were surrounded by an abundant mucoid, vacuolated stroma. The periphery of the tumor was enveloped by a significant lymphoplasmacytic infiltrate. The neoplastic cells were positive for vimentin and epithelial membrane antigen only. The unusual morphology of the tumor caused significant diagnostic difficulties. The differential diagnosis included inflammatory myofibroblastic tumor, spindle cell myoepithelioma, and extraskeletal myxoid chondrosarcoma. To the best of our knowledge, this is possibly the first description of an extracranial or intrapulmonary chordoid meningioma.

Ectopic neural and neuroendocrine neoplasms

Although neural and neuroendocrine tissues are distributed virtually ubiquitously throughout the body, the occurrence of selected neoplasms related to those lineages is extremely uncommon in some topographic sites. This review considers the clinicopathologic characteristics of heterotopic pituitary adenomas; neuroendocrine carcinomas in non-organ-based locations; ectopic (extraneuraxial) meningiomas and gliomas; visceral neuroblastic neoplasms and primitive neuroectodermal tumors; and paragangliomas arising outside the sympathoadrenal neural network. Practical approaches to differential diagnosis are emphasized.