Primary Smooth Muscle Tumor of the Pleura: A Clinicopathological Case Report with Ultrastructural Observations and a Review of the Literature

Abstract

Primary smooth muscle tumor of the pleura is exceptionally rare. The authors describe a primary smooth muscle tumor of the pleura that was discovered incidentally on chest X-ray in a 73-year-old man. Magnetic resonance imaging demonstrated a 12 x 18 x 15-cm pleura-based mass arising from the posterior mediastinum. Computerized tomography (CT) guided needle cores from the pleura showed a primary smooth muscle tumor of undetermined malignant potential. Further excision of the whole tumor showed an intimate relation to pleura, and the diagnosis of leiomyosarcoma was made. The clinical, radiological, histopathological, immunohistochemical, and ultrastuctural findings were consistent with a primary smooth muscle tumor of the pleura. This is the seventh case in the literature of a primary smooth muscle tumor of the pleura, which, to the best of the authors' knowledge, is the first such case of the pleura to be diagnosed on CT-guided needle biopsy. In conclusion, this method of investigation is recommended since it is minimally invasive but has a rewarding yield in providing the most likely diagnosis, predicting prognosis, and management planning.

Primary pleural leiomyosarcoma presenting as multiple pleural masses

“…Leiomyosarcomas are nearly uniformly positive for smooth muscle actin, desmin, and vimentin, and negative for calretinin, carcinoembryologic antigen, cytokeratin, leukocyte common antigen, neuroendocrine filament, and CD-117. [3,4] The histological and immunohistochemical characteristics of the lesions in this case demonstrated a PL.…”

“…[2] Most PLs are metastatic from uterus, gastrointestinal tract, and retroperitoneum. [3] It is named PPL if the pleura is the primary site. [2][3][4][5] The pathological examination of diaphragmatic masses in our case demonstrated a PL.…”

“…[3] It is named PPL if the pleura is the primary site. [2][3][4][5] The pathological examination of diaphragmatic masses in our case demonstrated a PL. The positron emission tomography demonstrated no other primary focus than the apical lesion, thus the final diagnosis was PPL.…”

“…[4,5] The tumor very rarely encases the lung like mesothelioma, but mostly forms a mass with or without pleural effusion. [2][3][4][5] Our case had three separate masses in the parietal pleura, and to the best of our knowledge, this is the first reported case of PPL with multiple foci in the English literature. It is known that leiomyosarcomas mostly spread to the body via hematogenous metastasis.…”

“…The need for adjuvant radiotherapy or chemotherapy depends on the tumor grade and the clinical stage of the patient. [3][4][5] Chemotherapy is indicated in case of a locally advanced or metastatic disease. [1] The most important factor affecting overall survival is margin status.…”