Rhabdomyosarcoma

Japanese: 横紋筋肉腫 - おうもんきんにくしゅ（英語表記）Rhabdomyosarcoma

What is the disease?

This is a sarcoma that shares common characteristics with skeletal muscle (striated muscle) in terms of the microscopic findings of the tumor and the proteins expressed in the tumor cells. It is one of the most common malignant tumors that occur in children, with two-thirds of cases occurring in children under the age of 10. It used to be one of the malignant tumors that was difficult to treat and had a poor prognosis, but today more than 70% of patients are able to overcome the disease. However, it is still true that there are still cases that are difficult to treat.

They can occur anywhere on the body, but most commonly around the eyes. Eye socket ( Cancer ) )or Parameningeal ( I'm so bored ) The head and neck area, such as near the surface of the brain, accounts for about 35% of the total. bladder ( Bladder ) It occurs in the urogenital organs such as the breast and prostate, and then in the hands and feet (limbs).

Based on the findings of tissue examination under a microscope, Alveolar type ( Report type ) It is classified into specific types, such as rhabdomyosarcoma and pleomorphic rhabdomyosarcoma, and each type has different genetic backgrounds, susceptible ages, and treatment outcomes.

What is the cause?

It is caused by complex genetic abnormalities, and the details are not yet known.

However, many cases classified as alveolar rhabdomyosarcoma have abnormalities in the sequence of certain chromosomes. In addition, in children, the disease is originally caused by genetic abnormalities. Neurofibromatosis ( New scientist ) It has been reported that this condition is more likely to occur in people with chronic kidney disease or Li-Fraumeni syndrome.

How symptoms manifest

Rapid growth Mass ( Production ) It develops as. Tumor ( Hump ) can be painful.

As a result of the growth of the aneurysm, the tumor may put pressure on the surrounding organs, causing symptoms. For example, if a tumor in the head grows and puts pressure on the brain or nerves, symptoms of nerve damage such as visual impairment, hearing impairment, decreased eye movement function, swallowing problems, and impaired consciousness may occur.

Testing and diagnosis

Diagnosis requires actual tissue samples to be examined under a microscope and, in some cases, specialized genetic testing.

In order to perform surgery with a low recurrence rate, the initial tissue collection method must also be planned, so MRI is taken to observe the local spread of the disease.

When the disease was discovered, CT scans of the chest and regional lymph nodes, bone scans, Bone marrow aspiration ( Kotsui Senshi ) Or we may do tests such as a bone marrow biopsy to see how far the disease has spread throughout the body, because treatment for this disease is planned based on how far the disease has spread throughout the body.

Treatment methods

The standard treatment is a combination of surgery, anticancer drugs and radiation therapy. Even if the image does not clearly show metastasis (the spread of malignant cells from the site where the disease first occurred to other organs via the blood or lymph flow), malignant cells often have spread throughout the body, so it is common to first perform anticancer drug treatment prior to surgery.

Anticancer drugs are an extremely effective treatment, and since their use began, treatment outcomes have improved dramatically. The five-year cumulative survival rate for this disease used to be around 25%, making it quite difficult to treat, but it is now around 70%.

When it occurs in the limbs, it is common to treat it without amputating the limb by using a surgical technique called wide resection, in which a large amount of normal tissue around the tumor is attached to the tumor. Amputation, which was once performed, is no longer necessary in most cases.

Radiation therapy may be used when a tumor remains in the body making surgery difficult or when there is lymph node metastasis.

What to do if you notice an illness

Treatment is required at specialized facilities such as cancer centers and university hospitals. Treatment is provided jointly by pediatricians, otolaryngologists, urologists, orthopedic surgeons, oncologists (chemotherapy), radiation therapists, and pathologists, each of whom brings together their specialized knowledge.

Kenji Morii

Source: Houken “Sixth Edition Family Medicine Encyclopedia” Information about the Sixth Edition Family Medicine Encyclopedia

Japanese:

どんな病気か

　腫瘍の顕微鏡所見や、腫瘍細胞に発現している蛋白質が、骨格筋（横紋筋）と共通の性質をもつ肉腫です。小児に発生する代表的な悪性腫瘍のひとつで、3分の2の症例は10歳以下に発生します。かつては治療が難しく、予後不良な悪性腫瘍のひとつでしたが、今日では70％以上の患者さんが病気を克服できるようになりました。とはいえ、今でも治療の難しい症例があるのも事実です。

　体中のあらゆる部分に発生しますが、最も多いのは眼のまわり（眼窩(がんか)）や傍髄膜(ぼうずいまく)と呼ばれる脳の表面近くなど頭頸部で、全体の約35％を占めます。その他、膀胱(ぼうこう)や前立腺などの泌尿生殖器、次いで手足（四肢）に発生します。

　顕微鏡で組織を観察した所見によって、胎児型横紋筋肉腫、胞巣型(ほうそうがた)横紋筋肉腫、多形型横紋筋肉腫などの細かいタイプに分類され、それぞれ遺伝子的背景、なりやすい年齢や治療成績が異なります。