Benign triton tumor Q87.-

Markel and Enzinger (1982)

Benign Triton tumor (BTT), also known as neuromuscular hamartoma, is a rare hamartoma occurring in a tumor form and consisting of mature neural as well as well-differentiated striated muscle elements (see also Triton tumor, malignant).

Mostly early childhood onset. Also in adolescents (Amita K et al. 2013). Occurrence in adulthood is an exceptional rarity (Bae DH et al. 2014).

The tumor formations primarily affect the major central cranial nerves and cause respective deficits (visual and auditory disturbances; facialis palsies- Bae DH et al. 2014; Gersdorff MC et al.1996; Corrales CE et al. 2010). Furthermore, they can occur as intracranial or as tumor masses of the spinal cord (Chapon F et al. 1991). In peripheral localization (peripheral nerves are affected), they may appear as asymptomatic cutaneous or subcutaneous nodules or nodules or as circumscribed swellings (see also case report).

Mixture of normally matured nerve trunks as well as striated and smooth muscles.

The name Triton tumor originated from studies of Triton salamanders in which supernumerary extremities grew with bone and muscle after implantation of sciatic nerves in the back.

Reported was the case of a 14-year-old boy who presented with an asymptomatic swelling of the chin over a period of 18 months which gradually increased and involved the left side of the lower lip. Clinically, a diagnosis of neurofibroma was made. An excisional biopsy confirmed the diagnosis of a "benign triton tumor" (Amita K et al. 2013).

1. Amita K et al (2013) Benign triton tumor: a rare entity in head and neck region. Korean J Pathol 47:74-76.
2. Bae DH et al (2014) Adulthood benign triton tumor developed in the orbit. J Korean Neurosurg Soc 56:146-148.
3. Chapon F et al. (1991) Lipome spinal associé à un hamartome neuromusculaire. A propos d'un cas. Ann Pathol11:345-348.
4. Corrales CE et al. (2010) Facial and vestibulocochlear nerve avulsion at the fundus of the internal auditory canal in a child without a temporal bone fracture. Otol Neurotol. 31:1508-1510.
5. Gersdorff MC et al.(1996) Neuromuscular hamartoma of the internal auditory canal. Eur Arch Otorhinolaryngol 253:440-442.
6. Markel SF et al. (1982) Neuromuscular hamartoma--a benign "triton tumor" composed of mature neural and striated muscle elements. Cancer 49:140-144.