A Rare Case of Spindle Cell Rhabdomyosarcoma of the Diaphragm in Adult with Thoracoabdominal Extension

Figure 1. Chest radiograph (PA view) showing an elevated right hemidiaphragm with a well-defined right lower thoracic opacity obscuring the right cardio-phrenic and blunting of costophrenic angle

Figure 2. Contrast-enhanced computed tomography demonstrating a large lobulated, heterogeneously enhancing soft-tissue mass centered on the right hemidiaphragm. Axial images (a-d) Shows extension into thoracic and abdominal compartments with compression of the intrahepatic and intrathoracic IVC and a few necrotic areas within. Coronal reformatted images (e-g) Shows transdiaphragmatic spread, with the supradiaphragmatic portion abutting the right atrium and the subdiaphragmatic portion infiltrating hepatic segments VII and VIII, causing irregular diaphragmatic thickening and mild perilesional fluid. Sagittal reformatted image (h) Shows continuity of supra- and subdiaphragmatic components centered on right dome of diaphragm. Maximum intensity projection image (i) Demonstrates arterial supply from the right inferior phrenic artery (white arrow)

Figure 3. T2-weighted MRI images demonstrating a large lobulated mass of right diaphragmatic origin. (a) Coronal image: Shows transdiaphragmatic extension into thoracic and abdominal compartments. (b) Sagittal image: Depicts continuity of the lesion across the right hemidiaphragm with associated diaphragmatic thickening and minimal pleural effusion

Figure 4. Histopathological study shows a spindle-shaped malignant neoplasm in interlacing fascicles, showing marked nuclear atypia, prominent nucleoli

Figure 5. Immunohistochemistry shows intense positivity for myogenin and MyoD1 Magnification value (400x)