Large small cell carcinoma of anorectal canal.

Neurofibromatosis type-1 (NF1), also known as Von Recklinghausen disease, is an autosomal dominant disorder with incidence of one per 4000. Neurofibromas are benign, heterogeneous, peripheral nerve sheath tumors coming up from the connective tissue of peripheral nerve sheaths, particularly the endoneurium. Visceral involvement in disseminated neurofibromatosis is considered rare.