Rhabdomyosarcoma is a rare malignant tumor that can present in the oral cavity These fast-growing, ulcerative lesions may present with bleeding Associated signs and symptoms are usually attributed to the mass lesion or obstructive sequelae Other malignancies such as fibrosarcoma, epidermoid carcinoma, carcinoma of the parotid, minor salivary gland malignancies, osteosarcoma, histiocytosis, and lymphoma may also present as intraoral mass lesions Mucosal neuromas can be a presenting sign of multiple endocrine neoplasia type 2B FIGURE 52.4 Melanotic neuroectodermal tumor of infancy Oral Lesions Associated With Systemic Disease Stevens–Johnson syndrome is a potentially life-threatening illness involving necrosis and detachment of the epidermis of skin and mucous membranes It is most commonly triggered by medications, although infection may also be implicated Oral lesions include erythema, erosions, scabs, and pseudomembranes often preceded by fever, malaise, and dysphagia Removal of the offending medication is key, followed by intensive supportive care Erythema multiforme, classically presenting with polychromatic target lesions, can also demonstrate mucosal involvement, including erythema, erosions, or bullae It is commonly triggered by infections, including herpes simplex virus or Mycoplasma