Rhabdomyomatous (Mesenchymal) Hamartoma Presenting as Haemangioma on the Upper Lip: A Case Report with Immunohistochemical Analysis and Treatment with High-Power Lasers

Abstract

Rhabdomyomatous hamartoma is a rare disease that occurs predominantly in the skin. This paper describes a congenital lesion in a 17-year-old male, who came to our clinic presenting a circumscribed swelling involving the oral mucosa and vermillion border of the upper lip, purplish in color, and blanching under pressure. The patient reported that he had had lesion since his birth. A clinical diagnosis was of congenital haemangioma, and the patient was treated by photocoagulation using diode laser. When the lesion became smaller, by having its blood content reduced, the upper portion of the lesion was sliced off with CO2 laser and the tissue was sent for microscopic analysis. Histopathological examination showed an oral mucosa fragment with proliferation of striated muscle bundles admixed with small blood vessels, collagen, and nerve fibres. A supplementary analysis with immunohistochemistry demonstrated positivity for desmin, HHF35, smooth muscle actin, S-100, and CD34. Based on these findings, the lesion was diagnosed as rhabdomyomatous hamartoma. The aesthetic result has been very satisfactory after a 14-month followup.

Rhabdomyomatous mesenchymal hamartoma presenting as a sacral skin tag in two neonates with spinal dysraphism

“…Rhabdomyomatous mesenchymal hamartoma (RMH) is a rare malformation with 62 reported cases through 2014 . It was first described in 1986 by Hendrick et al as a striated muscle hamartoma and was later termed RMH by Mills et al in 1989 .…”

Combined cutaneous smooth muscle hamartoma and nevus flammeus

“…There is also a recent publication in the oral medicine literature regarding a rhabdomyomatous hamartoma combined with a hemangioma on the upper lip . However, in this case, the bundles were made of striated muscle instead of smooth muscle.…”

Rhabdomyomatous mesenchymal hamartoma presenting as a big subcutaneous mass on the neck: a case report

“…RMH occurs most commonly in areas where there is superficial striated muscle, such as the nose or chin, followed by the periorbital and anterior neck areas. Most cases have been described in young patients on the head and neck [ 1 ], such as periorbital [ 5 ], nasal alae [ 6 ], lip [ 7 ], chin [ 8 ], tongue and tonsil [ 9 ], and sternoclavicular area [ 10 ]. There is no apparent sex predilection.…”