What are the other Names for this Condition? (Also known as/Synonyms)

• Congenital Midline Hamartoma of Skin
• Cutaneous Rhabdomyomatous Mesenchymal Hamartoma
• Striated Muscle Hamartoma of Skin

What is Rhabdomyomatous Mesenchymal Hamartoma of Skin? (Definition/Background Information)

• Rhabdomyomatous Mesenchymal Hamartoma (RMH) of Skin is an extremely rare, benign tumor of the skeletal muscle fibers and skin. It is a hamartoma, meaning an abnormal growth, and is frequently observed in infants and young children
• The tumor is usually painless and solitary, and is generally present on the midline of the head and neck region including on the nose or chin. The size of the tumor may apparently change, as the baby cries or feeds
• Rhabdomyomatous Mesenchymal Hamartoma of Skin may be rarely associated with disorders such as Goldenhar syndrome, amniotic band syndrome, and Delleman syndrome. The cause of the condition is unidentified, but some researchers believe that it may be due to genetic factors
• A simple surgical excision of the tumor is considered curative. The prognosis for Rhabdomyomatous Mesenchymal Hamartoma of Skin is excellent with suitable treatment. In case of an underlying disorder, then the prognosis depends upon the severity of the same

Who gets Rhabdomyomatous Mesenchymal Hamartoma of Skin? (Age and Sex Distribution)

• Rhabdomyomatous Mesenchymal Hamartoma of Skin is mostly seen following birth of the baby or during early childhood. Infrequently, an adult manifestation of this tumor is known to take place
• RMH of Skin is a very rare kind of soft tissue tumor and less than 50 cases have been reported worldwide
• Both males and females are affected, though a preference for males is noted (2:1 male-female ratio)
• Individuals of all racial and ethnic background can be affected

What are the Risk Factors for Rhabdomyomatous Mesenchymal Hamartoma of Skin? (Predisposing Factors)

• Currently, no specific risk factors have been identified for the formation of Cutaneous Rhabdomyomatous Mesenchymal Hamartoma
• Isolated cases of tumor association with Goldenhar syndrome, amniotic band syndrome, and Delleman syndrome, has been recorded
• So far, a positive family history of the tumor has not been reported

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Rhabdomyomatous Mesenchymal Hamartoma of Skin? (Etiology)

The cause of development of Rhabdomyomatous Mesenchymal Hamartoma of Skin is presently unknown.

• Some scientists believe that these tumors are abnormal tissue development remnants from the fetal growth and development stage
• Some believe that the tumors develop due to a genetic abnormality

What are the Signs and Symptoms of Rhabdomyomatous Mesenchymal Hamartoma of Skin?

Most Rhabdomyomatous Mesenchymal Hamartomas of Skin are asymptomatic. In some, the signs and symptoms observed include:

• It usually occurs as a single, benign tumor on the skin
• The lesion may be dome-shaped or polyp-shaped in most cases; polypoid tumors may be pedunculated (a sac-like structure attached to the underlying skin by a narrow stalk)
• The lesion is usually seen on the midline of the head and neck region, mostly on the chin and nose. Due to this, the tumor is also known as Congenital Midline Hamartoma of Skin
• Other locations include the cheek, region around the ears, and forehead. Certain unusual tumor sites include the mouth and vagina
• Some RMH tumors may be nodular or sessile (attached to the skin and immobile)
• As the baby’s facial muscles or head moves, such as during crying or feeding, the tumor is known to temporarily shrink in size; this is known as ‘contractile motion’
• Rarely, multiple tumors may be observed along-with other genetic conditions. In such cases, the presence of signs and symptoms of the underlying condition, if any, may be noted

How is Rhabdomyomatous Mesenchymal Hamartoma of Skin Diagnosed?

A diagnosis of Rhabdomyomatous Mesenchymal Hamartoma of Skin may involve the following:

• A thorough medical history and physical examination
• Dermoscopy: It is a diagnostic tool where a dermatologist examines the skin using a special magnified lens
• Wood’s lamp examination: In this procedure, the healthcare provider examines the skin using ultraviolet light. It is performed to examine the change in skin pigmentation
• Tissue biopsy: A tissue biopsy is performed and sent to a laboratory for a pathological examination. The pathologist examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis
• A differential diagnosis may be necessary prior to establishing a definitive diagnosis, by excluding the following tumors:
  • Fibroepithelial polyp
  • Nevus lipomatosus
  • Embryonal rhabdomyosarcoma
  • Fibrous hamartoma of infancy
  • Benign triton tumor
  • Fetal rhabdomyoma

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Rhabdomyomatous Mesenchymal Hamartoma of Skin?

Rhabdomyomatous Mesenchymal Hamartomas of Skin generally do not cause any significant complications. However, the following factors may be a cause for concern:

• The presence of some tumors may result in cosmetic issues
• Complications due to the presence of other genetic disorders

How is Rhabdomyomatous Mesenchymal Hamartoma of Skin Treated?

The treatment of Rhabdomyomatous Mesenchymal Hamartoma of Skin may include the following:

• The removal of the tumor may not be necessary, unless it causes worrisome signs and symptoms such as cosmetic issues. The healthcare provider may undertake a ‘watchful waiting’ approach following a diagnosis of Cutaneous Rhabdomyomatous Mesenchymal Hamartoma
• However, the treatment of choice is a complete surgical excision, which can result in a cure
• Undertaking treatment for any underlying condition(s)

How can Rhabdomyomatous Mesenchymal Hamartoma of Skin be Prevented?

Currently, there are no known methods available to prevent the occurrence of Rhabdomyomatous Mesenchymal Hamartoma of Skin.

What is the Prognosis of Rhabdomyomatous Mesenchymal Hamartoma of Skin? (Outcomes/Resolutions)

• The prognosis for Rhabdomyomatous Mesenchymal Hamartoma of Skin is generally excellent with appropriate treatment, since it is a benign tumor
• Nevertheless, the overall prognosis also depends upon the presence of any underlying syndrome and the severity of the symptoms associated with it

Additional and Relevant Useful Information for Rhabdomyomatous Mesenchymal Hamartoma of Skin:

• There is no evidence to prove that oily foods and chocolate-based products have an influence on the condition
• Cleaning the skin too hard with strong chemicals or soaps may aggravate the skin condition. Care must be taken avoid strong soaps and chemicals that could potentially worsen the condition
• The presence of dirt on the body is not a causative factor for the condition. However, it helps to be clean and hygienic, which may help the condition from getting worse