Non-neoplastic glandular structures in a benign peripheral nerve sheath tumor.

It is a recognized fact that glandular structures sometimes occur in peripheral nerve sheath tumors (PNST). Reports indicate that epithelial potential could be expressed in malignant PNST, while the glands in most benign PNST could be trapped skin adnexa. We present a case of spindle cell tumor with glandular structures. The patient was a 55-year-old man who had a subcutaneous tumor excised. The spindle cell tumor had histological characteristics of neurofibroma. The glandular structures had a pattern of immunohistochemical staining that was similar to that of the secretory coils and excretory ducts of normal eccrine glands. Therefore, the glands were thought to be naturally existing eccrine glands. The glands were completely enclosed within the tumor and not connected to one another; a cluster formation was not observed. The upper portion of tumor included some glands of skin adnexa. The spindle cell tumor may have originated from the nerves distributed around the skin adnexa, and grown to the subcutaneous tissue. The glands may have been left behind rather than have been trapped in the tumor.