Primary Leiomyoma of the Visceral Pleura: An Unexpected Occurrence

Leiomyoma is a rare benign tumor originating from smooth muscle fibres. In the respiratory tract, these tumors are rare and in the pleura, cases are exceptional, with only a few reported so far. This is the main reason we decided to present this case of primary leiomyoma of the visceral pleura.

We present a case of a 51-year-old asymptomatic patient who, during a routine medical examination using standard chest radiography, presented with a 3 by 2 cm homogenous mass in the right superior pulmonary area, tangent to the chest wall (same level with the 3^rd rib). Further investigation using computed tomography (CT) in the chest confirmed the presence of a 31/18 mm solid mass in the right upper lobe, in contact with the parietal pleura. Surgery was performed for two reasons: i) removal of the tumoral mass and ii) establishing a histopathological diagnosis. Intraoperatively, a well-defined, homogenous, ivory white non-infiltrating mass was discovered in the right upper lobe on the visceral pleura and in close proximity to the minor fissure. The mass was removed with negative surgical margins and was left with healthy tissue. Histopathological examination and immunohistochemistry came as a surprise, establishing our diagnosis of leiomyoma.

Primitive pleural leiomyoma must remain a possibility when considering the differential diagnosis of pleural tumors. The main course of treatment is complete surgical resection. In our case, long-term follow up did not present any local recurrence.