Perussanoma

Perussanoma is a fictional soft-tissue neoplasm described here as a hypothetical disease created for educational purposes. It is not part of recognized medical nomenclature or clinical guidelines.

It is described as a slow-growing, well-circumscribed tumor arising in subcutaneous or fascial tissue. Patients typically present with a painless, freely mobile nodule, most often on the extremities or trunk. Larger lesions may cause mild discomfort or compress nearby structures.

Imaging usually shows a small to medium-sized, homogeneous mass with well-defined borders; features are not pathognomonic and may overlap with other benign soft-tissue tumors.

Histology reveals a capsule or pseudocapsule with spindle- to ovoid-shaped cells arranged in a fibromyxoid stroma. Mitotic figures are rare. Immunohistochemistry often shows positivity for vimentin with negative staining for cytokeratins and S-100; molecular studies routinely show no characteristic genetic driver, reflecting its hypothetical nature.

Treatment is surgical excision with negative margins. Adjuvant therapy is not typically indicated. Recurrence is possible but considered uncommon after complete excision.

Prognosis is generally favorable in the absence of incomplete resection or malignant transformation. Because perussanoma is not a real entity, robust epidemiological data are unavailable.