Pseudolymphomatous Cutaneous Angiosarcoma Presenting With Persistent Firm Facial Edema in a Patient With Systemic Sclerosis.

Pseudolymphomatous cutaneous angiosarcoma (cAS) is a rare subtype characterized by a prominent lymphocytic infiltrate, posing diagnostic challenges due to its resemblance to lymphoid neoplastic processes. We present a novel case highlighting the clinical and histopathological features, notably its association with persistent firm facial edema in a patient with systemic sclerosis (SSc). A 47-year-old woman with a 21-year history of SSc presented with firm palpebral edema evolving to involve the entire face and cervical region over six months. Diagnostic imaging revealed inflammatory changes in orbital regions, supradiaphragmatic lymphadenopathies, and lytic lesions. Skin biopsy demonstrated a diffuse neoplasm with vascular channels and solid areas, accompanied by dense lymphocytic proliferation. Pseudolymphomatous cutaneous angiosarcoma, a rare malignant neoplasm, exhibits variable clinical presentations and rapid progression. Histologically, it manifests as irregularly shaped vascular channels lined by prominent endothelial cells. Immunohistochemistry, particularly markers such as v-ets erythroblastosis virus E26 oncogene homolog (avian) (ERG), aids in diagnosis. Notably, this case marks the first presentation of cAS with persistent facial edema in SSc, highlighting the association between SSc and cancer risk. This case underscores the diagnostic challenges posed by cAS and emphasizes the importance of early detection for optimal patient outcomes. Further understanding of its association with autoimmune disorders such as SSc is crucial for comprehensive management strategies.