IPMs are diagnosed by examination of the tissue by a pathologist. They have a rim of peripheral lymphoid tissue (remnant of a lymph node) and consist of spindle cells with nuclear palisading. Red blood cell extravasation is common and blood vessels surrounded by collagen with (fine) peripheral spokes (amianthoid fibers) are usually seen. Immunostains for smooth muscle actin and cyclin D1 are characteristically positive. The main histologic differential diagnosis is schwannoma. Image:<unk>  - low mag. Low mag. Image:<unk>  - high mag. High mag.
Intranodal palisaded myofibroblastoma
Mammary-type myofibroblastoma
Folliculosebaceous cystic hamartoma
Basaloid follicular hamartoma
Germ cell neoplasia in situ
Lipofibromatosis-like neural tumor
Solitary cutaneous leiomyoma
In situ lymphoid neoplasia