Cutaneous Angiosarcoma Mimicking Masson’s Tumor in an Elderly Male: A Diagnostic Challenge and Treatment Failure

Figures

• 

  Figure 1. An initial biopsy from a nodule showed prominent papillary endothelial proliferation within a vascular space, with thickened hyperplastic endothelium forming non-encapsulated papillary structures infiltrating the stroma, consistent with Masson’s tumor (low magnification x4, with hematoxylin & eosin stain).

• 

  Figure 2. Under higher magnification, papillary structures were lined by flattened endothelial cells with mild atypia and no significant mitotic activity. Vascular channels contained red blood cells and minimal fibrin deposits, with early thrombosis noted in some areas (intermediate magnification x10, with hematoxylin & eosin stain).

• 

  Figure 3. The lesion’s intravascular location showed multiple small, rounded papillae covered by hyperplastic endothelial cells, projecting into the lumen of an existing blood vessel, without destructive growth or significant atypia, supporting a benign nature (high magnification x40, with hematoxylin & eosin stain).

• 

  Figure 4. Several vascular channels lined by mildly reactive endothelial cells appeared partially occluded by organized thrombi undergoing recanalization—a hallmark of Masson’s tumor. The surrounding tissue had low cellularity and mild inflammation (high magnification x100, with hematoxylin & eosin stain).

• 

  Figure 5. Extensive endothelial proliferation nearly occluded the vascular lumen, with endothelial cells showing a slightly increased nucleus-to-cytoplasm ratio but maintaining a benign appearance. Focal fibrin deposits and early thrombus organization were critical diagnostic features (high magnification x100, with hematoxylin & eosin stain).

• 

  Figure 6. The facial lesion consists of multifocal, indurated nodules with a violaceous hue, primarily affecting the cheeks, nasal bridge, and periocular areas, with signs of superficial ulceration and crusting.

• 

  Figure 7. The second biopsy showed a highly cellular tumor infiltrating the dermal and subcutaneous layers, with irregular, blood-filled channels lined by atypical endothelial cells, indicating neovascularization. The cells displayed pleomorphism and hyperchromasia, with rudimentary lumen formation in some areas. Sparse inflammatory infiltrates were present in the reactive stroma (low magnification x4, with hematoxylin & eosin stain).

• 

  Figure 8. At higher magnification, the tumor’s aggressiveness was evident, with significant nuclear atypia, numerous mitotic figures, and disorganized vascular channels disrupting the collagenous stroma—indicating malignant invasion into adjacent tissues (intermediate magnification x10, with hematoxylin & eosin stain).

• 

  Figure 9. Spindle-shaped endothelial cells with irregular nuclei and visible nucleoli were embedded within a myxoid stroma, alongside sporadic multinucleated giant cells (high magnification x40, with hematoxylin & eosin stain).

• 

  Figure 10. Higher magnification of Figure 9 showing spindle-shaped endothelial cells with irregular nuclei and prominent nucleoli within myxoid stroma, accompanied by occasional multinucleated giant cells. These features aligned more closely with cutaneous angiosarcoma than with Masson’s tumor (high magnification x100, with hematoxylin & eosin stain).