Cutaneous metastases are uncommon dermatologic manifestations, occurring in 0.7–0.9% of cancer patients. They typically originate from malignancies of the breast, lung, or gastrointestinal tract, with only a few reported cases arising from malignant cardiac tumors. Herein, we present a rare case of cutaneous metastasis from a primary cardiac myxofibrosarcoma (MFS). Based on available literature, this is the first documented case in the Philippines.

A 26-year-old man presented with rapidly enlarging nodules on the mandible and left thigh following the early recurrence of a previously excised cardiac myxoma. A biopsy of the skin lesions demonstrated a bottom-heavy distribution of atypical spindle cells in a myxoid stroma, raising suspicion of either a primary spindle cell neoplasm or cutaneous metastasis. This prompted a multidisciplinary investigation into the underlying malignancy. Histopathology and immunohistochemical staining of both the cardiac mass and skin lesions confirmed a diagnosis of cardiac MFS with cutaneous metastasis. The aggressive nature of MFS, combined with the presence of metastasis and the patient’s decision to decline further treatment, led to rapid clinical deterioration and ultimately, death.

Cutaneous metastasis from cardiac tumors is exceedingly rare and difficult to diagnose given the paucity of reported cases. This case highlights the pivotal role of dermatologists in recognizing these dermatologic manifestations, prompting further investigation into the underlying malignancy. Dermatologists must maintain a high index of suspicion when evaluating skin lesions of patients with a history of malignancy, given the significant treatment and prognostic implications.