Having great healthy skin can mean a lot to a person. It can make a person be confident of themselves and may also make them attractive. A healthy skin can also make a person look younger than their real age. The journey of having a healthy skin can seem different to one person and another. Some may have this even without the need to get treatment but reality speaking, to have a healthy skin often need treatment or extra care. There are many skin disorders that can deteriorate skin health. In this DoctorOnCall’s article, we will be learning about one of the many skin disorders known as lipoma.
Lipoma are soft and fatty lumps that grow under the skin. It is a benign lump and not cancerous. It is formed due to an overgrowth of fat cells. Lipoma is not the same as liposarcomas. Liposarcomas are cancerous tumours for the fat cells and a type of soft tissue sarcoma. When lipoma arises inside the muscle, it is known as intramuscular lipomas. From here on, we will be focusing on intramuscular lipoma.
Intramuscular lipoma is uncommon making it difficult to know how many are truly affected by the condition. It is also known as a very rare form of lipoma. Furthermore, intramuscular lipoma is often put together with other deep-seated and superficial lipomas. Relatively, intramuscular lipomas account for 1.8% of all tumours of adipose (fat) cells and less than 1% of all lipomas. While lipomas are estimated to be multiple in 5-15% of patients, most intramuscular lipomas are located within a single muscle with only a few cases involving 2 or more muscles. Intramuscular lipomas may occur in all ages but the majority occur between the age 40 to 70 years old.
Intramuscular lipomas primarily occur in the large muscles of the limbs and trunk, but can occur in almost any muscle of the body. The most common location was the thigh followed by shoulder. 47% of intramuscular lipomas arose in the upper limb or chest wall. Intramuscular lipomas of the hand and foot are rare.
The exact cause of intramuscular lipomas are not known. Similar to other lipoma subtypes, intramuscular lipomas most likely have the same nature of disease as neoplasm or tumour originating from multipotential mesenchymal cells. The uncontrolled growth of lipomas that suggest to play a role in development of intramuscular lipomas are said to be associated with factors such as trauma, long-term irritation, obesity, developmental disorder, endocrine and genetic factors.
There are few types of intramuscular lipomas such as infiltrating intramuscular lipomas, well-defined (well-circumscribed) intramuscular lipomas and mixed intramuscular lipomas. To know which types of intramuscular lipomas, microscopy tests are needed to seek for its cell and tissue structures (histological features). Cytology tests can help determine the gene responsible for the changes in the intramuscular lipomas.
Intramuscular lipomas most often initially be presented as slowly growing mass or swelling with no symptoms. The mass is also unable to be detected through touch (no palpable mass). Pain is uncommon and even if it does occur, it is usually late. Pain may be resulted from the deep and very large lipomas that have put pressure or expand to the nearby soft tissues or compress the nerve. Since it may affect the nerve, it can cause an abnormal sensation known as paraesthesia which is often described as burning, prickling, tingling or numbness and often painless. Affected nerves may also cause nerve problems such as movement issues due to nerve impingement. Some patients may complain of occasional cramping. Symptoms may vary from months to years before it is able to be diagnosed. Symptoms vary greatly according to the site affected and can mimic other more common diseases. For example, intramuscular lipoma around the pectoralis muscle may mimic breast cancer and when in muscle of the arm, may be similar to impingement syndrome.
In most cases of intramuscular lipomas, the patient does not receive treatment. Small lipomas that do not cause problems in a patient’s life, only need observation by doctors. Hence, there is no need to remove it unless the condition has caused symptoms such as pain or other problems. In such a case, the patient might need surgery to remove it. Surgery is commonly done through excision. In general, treatment depends on the location of the mass, size and symptoms caused by the lesion. It is important to note that intramuscular lipoma may come again even after treatment, especially in case of incomplete removal of the lipomas during surgery. The lipomas can develop again years after excision.
It can be concluded that intramuscular lipomas are relatively the uncommon subtype of lipomas. It is still a rare condition, making it difficult to be identified soon and often misdiagnosed with other conditions. Thus, patients that show symptoms should always seek medical advice to ensure doctors can do careful assessment and all the tests needed to identify the issue. This will help to provide patients with the best treatment and hopefully favourable outcome.
