A Rare Entity: Primary Pulmonary Meningioma
Aynur BAŞ1, Elgün VALIYEV2, Nur DILVIN ÖZKAN2, İsmail TOMBUL2, Selcen YONAT3, Muhammet SAYAN2, İsmail Cüneyt KURUL2
1Basaksehir Cam and Sakura City Hospital, Department of Thoracic Surgery, ISTANBUL, TURKEY
2Gazi University, School of Medicine, Department of Thoracic Surgery, ANKARA, TURKEY
3Gazi University, School of Medicine, Department of Pathology, ANKARA, TURKEY
Meningioma is the most common tumor of the central
nervous system (CNS). Except for the CNS, it can be
detected at a rate of 1-2% in the head and neck region.
Primary pulmonary meningiomas (PPM) are extremely
rare. They are detected incidentally as a solitary pulmonary
nodule during radiological examinations. On computerized
tomography (CT), the lesions are generally seen as a
uniform and homogeneous mass. Although they are usually
benign and the prognosis is excellent, they may be subject
to misdiagnosis and overtreatment. 1-3. Here we have
aimed to present a case of primary pulmonary meningioma
that appeared as a solitary pulmonary nodule and to discuss
its clinical and pathological features.
A 57-year-old male patient with cough had been on
follow-up for five years. His medical history included 30
pack-year smoking history, hypertension, arrhythmia, and
hypercholesterolemia. In 2015, a well-circumscribed lesion
10 mm in diameter had been detected in the subpleural
area of the left lower lobe with thorax CT. There was no
pathological uptake of 18F-FDG on PET-CT. The patient
was put on radiological follow-up. There was no change
in the nature of the nodule during the 3-year follow-up
period and in the control thorax CT obtained in 2018, and
the follow-up was continued with chest x-rays. During
follow-up in January 2020, it was determined that the chest
nodule had a similar appearance with the previous followups,
but there was a slight increase in density, and a newly
developing nodule with a size of 7 mm had appeared in the
neighboring parenchyma (Figure 1). Based on the available
findings, a decision was made for surgery to enable
histopathological confirmation. A frozen section was sent
following wedge resection for both lesions in the lower left
lobe. The operation was terminated when the lesion 11 mm
in diameter was reported as pulmonary meningioma as a
result of frozen section analysis. The other nodule was a
parenchymal lymph node and the surgical margins were
tumor free. In the final histopathological analysis, it was
reported that the 8 mm nodule diagnosed with PPM was
immunohistochemically positive for vimentin, EMA, and
progesterone receptors. Psammoma bodies were seen but
mitosis and necrosis were not observed (Figure 2A,B,3A,B).
The patient was evaluated with MRI for possible central
nervous system meningioma but no meningioma was
detected. The patient was discharged without any
complications in the postoperative period.
Click Here to Zoom
|Figure 1: Thorax CT depicting a well-circumscribed lesion 10 cm
in diameter in the subpleural area of the left lower lobe (arrow).
Click Here to Zoom
|Figure 2: A) Microscopic
examination showed spindle
to round cells with whorl
formation (H&E; x100).
B) The tumor cells showed
positive staining with vimentin
Click Here to Zoom
|Figure 3: Immunohistochemical
examination showed positive
staining with A) progesterone
receptor (IHC; x100) and
B) EMA (IHC; x200).
PPMs are usually asymptomatic lesions that appear
incidentally. However, patients with large tumors may have symptoms related to the localization, such as chest
pain and cough. It has been reported that the lesion is
generally detected between the ages of 40 and 60. Since
the first case-report by Kemnitz in 1982, about 60 cases of
PPM were published in the English literature 1. Our case
was 57 years old, in accordance with the literature. Many
benign PPMs have been reported to be misdiagnosed and
consequently undergone extensive pulmonary resections
and/or chemotherapy 4. In 2008, it was reported that 32%
of patients who underwent major surgical resection and
received chemotherapy had been misdiagnosed 4. In the
literature, it is widely accepted that a wedge resection with
tumor-free margins is sufficient for the treatment of benign
PPM. The prognosis is reported to be excellent and extended
resections are not required 3-5. In accordance with the
literature, we performed wedge resection in the case. The
definitive diagnosis of PPM was made histopathologically
and immunohistochemically. Epithelial, transitional
and fibrous types are possible. Immunohistochemically,
vimentin and EMA are expressed together in most cases 3.
Our patient also had a positive reaction for vimentin and
EMA. The absence of necrosis and mitosis also supports
the diagnosis of benign PPM. It has been reported that the
prognosis of PPM is excellent and there was a case that has
been followed for more than 20 years 5.
In conclusion, PPMs mostly appear radiologically in the
form of pulmonary nodules, are usually benign, and have
a good prognosis. PPM should also be kept in mind in the
differential diagnosis of SPN.
CONFLICT of INTEREST
The authors declare no conflicts of interest.
1) Vaideeswar P, Chaudhari J. Primary pulmonary meningioma.
Indian J Pathol Microbiol. 2019;62:486-7.
2) Huang S, Chen L, Mao Y, Tong H. Primary pulmonary
meningioma: A case report. Medicine (Baltimore). 2017;96:e6474.
3) Xu KK, Tian F, Cui Y. Primary pulmonary meningioma
presenting as a micro solid nodule: A rare case report. Thorac
4) Incarbone M, Ceresoli GL, Di Tommaso L, Cappuzzo F, Inzirillo F,
Infante M, Alloisio M. Primary pulmonary meningioma: Report
of a case and review of the literature. Lung Cancer. 2008;62:401-7.
5) Satoh Y, Ishikawa Y. Multiple primary pulmonary meningiomas:
20-year follow-up findings for a first reported case confirming a
benign biological nature. Int J Surg Case Rep. 2017;31:58-60.