Benign metastasizing leiomyoma is a rare condition characterized by the growth of uterine leiomyoma in the other regions especially the lungs.

Mesenchymal neoplasms of the gallbladder are rare and in particular leiomyomas of the gallbladder have been rarely reported, all of them in patients with immune system disorders. Although, recently, a case was reported in absence of associated immunodeficiency at Monash Hospital in Melbourne Australia in a healthy 39-year-old woman with no symptoms.

Leiomyoma is the most common benign mesenchymal tumor of esophagus and second most common benign tumor of the small bowel (with gastrointestinal stromal tumor as most common). Although leiomyoma is the most common benign esophageal tumor, malignant carcinoma is still 50 times more likely. Approximately 50% of cases are found in the jejunum, followed by the ileum in 31% of cases. Almost one half of all lesions are less than 5 centimeters.

Angioleiomyoma (vascular leiomyoma, angiomyoma) of the skin is thought to arise from vascular smooth muscle, and is generally acquired.

A 2006 review stated that RS often leads renal cancer between ages 30-50. Renal cancer kills about 1 in 3 people, but 5-year survival rates improved between 1974-1976 and 1995-2000, from 52% to 64%.

Uterine sarcoma are rare, out of all malignancies of the uterine body only about 4% will be uterine sarcomas. Generally, the cause of the lesion is not known, however patients with a history of pelvic radiation are at higher risk. Most tumors occur after menopause.

Women who take long-term tamoxifen are at higher risk.

Diets high in fruits and vegetables tend to lower the risk of developing fibroids. Fruits, especially citrus, have a greater protective benefit than vegetables. Normal dietary levels of vitamin D is shown to reduce the risk of developing fibroids. No protective benefit has been found with the consumption of folate, whole grains, soy products, or fiber. No association between the consumption of fat, eggs, dairy products has been shown to increase the risk of fibroids.

Intravenous leiomyomatosis is a rare condition seen exclusively in women in which leiomyomata, benign smooth muscle tumors, are found in veins. The masses are benign-appearing but can spread throughout the venous system leaving the uterus and even cause death when growing into the heart from the IVC. While the possibility that these arose de novo from the smooth muscle in the blood vessel wall was considered, chromosomal analysis suggests a uterine origin. Intravenous leiomyomata are usually but not always associated with uterine fibroids, and tend to recur.

This condition is related to benign metastasizing leiomyoma, in which the masses appear in more distant locations such as the lung and lymph nodes.

This is a very rare phenomenon (50 years of age), and more commonly in women than men (5:1). There is an increased frequency in Okinawa, Japan, but this may be a reporting bias.

The tumor develops very specifically in the subscapular or infrascapular area, deep to the muscle, sometimes even attached to periosteum of ribs. It is usually between the shoulder blade and the lower neck, with rare tumors reported in the chest wall.

Solitary cutaneous leiomyoma typically presents as a deeply circumscribed, freely movable, rounded nodule ranging from 2 to 15mm in diameter, with overlying skin that may have a reddish or violaceous tint.

Other relatively rare conditions have been reported in association with this disease. It is not yet known if these associations are fortuitous or manifestations of the condition itself.

Cerebral cavernomas and massive, macronodular adrenocortical disease have also been reported in association with this syndrome. A case of cutis verticis gyrata, disseminated collagenoma and Charcot-Marie-Tooth disease in association with a mutation in the fumarate hydratase gene has also been reported. Two cases of ovarian mucinous cystadenoma have also been reported with this mutation.

Chondroid lipomas are deep-seated, firm, yellow tumors that characteristically occur on the legs of women. They exhibit a characteristic translocation t(11;16) with a resulting C11orf95-MKL2 fusion oncogene.

Some risk factors associated with the development of uterine fibroids are modifiable.

Fibroids are more common in obese women. Fibroids are dependent on estrogen and progesterone to grow and therefore relevant only during the reproductive years.

To remove the tumor from the body, a myomectomy or hysterectomy is often required.

Superficial lymphatic malformation (also known as "Lymphangioma circumscriptum") is a congenital malformation of the superficial lymphatics, presenting as groups of deep-seated, vesicle-like papules resembling frog spawn, at birth or shortly thereafter.

They are of two types.

- The leiomyoma occurs in the skin or gut but the common form is the uterine fibroid.

- Rhabdomyomas are rare tumors of muscles, they occur in childhood and often become malignant.

Inflammatory fibroid polyp, abbreviated IFP, is a benign abnormal growth of tissue projecting into the lumen of the gastrointestinal tract.

A Cystic lymphatic malformation is a deep-seated, typically multilocular, ill-defined soft-tissue mass that is painless and covered by normal skin. These malformations may further be divided into macrocystic lymphatic malformations and microcystic lymphatic malformations.

Cavernous venous malformations present as rounded, bright red or deep purple, spongy nodules, occurring chiefly on the head and neck and may involve both the skin and the mucous membranes.

It can be associated with "KRIT1", "CCM2" or "PDCD10".

Surgery, with as wide a margin of removal as possible, has generally been the most effective and preferred way to attack LMS. If surgical margins are narrow or not clear of tumor, however, or in some situations where tumor cells were left behind, chemotherapy or radiation has been shown to give a clear survival benefit. While LMS tends to be resistant to radiation and chemotherapy, each case is different and results can vary widely.

LMS of uterine origin do frequently, but not always respond to hormonal treatments.

There are several theories about origin:

- There is support for a genetic predisposition, as there are alterations of short arm of chromosome 1;

- Multifocality may suggest systemic enzymatic defect, resulting in abnormal elastogenesis;

- Repeated trauma or friction seems unlikely, but is still a possibility.

IFPs consist of spindle cells that are concentrically arranged around blood vessels and have inflammation, especially eosinophils.

They may have leiomyoma/schwannoma-like areas with nuclear palisading.

They typically stain with CD34 and vimentin, and, generally, do not stain with CD117 and S100.

The endoscopic differential diagnosis includes other benign, pre-malignant and malignant gastrointestinal polyps.

Smooth muscle tumor of uncertain malignant potential, abbreviated STUMP, is an uncommon tumor of the uterine smooth muscle that may behave like a benign tumor or a cancerous tumor.

This tumor should not be confused with the prostatic stromal tumor of uncertain malignant potential which may be abbreviated the same way ("STUMP").

The Bell criteria were developed to help categorize them and differentiate them from their main differential diagnoses, leiomyosarcoma and uterine leiomyoma.

Blue nevus (also known as "blue neuronevus", "dermal melanocytoma", and "nevus bleu") is a type of melanocytic nevus. The blue colour is caused by the pigment being deeper in the skin than in ordinary nevi. In principle they are harmless but they can sometimes be mimicked by malignant lesions, i.e. some melanomas can look like a blue nevus.

Smooth muscle tumours show a smooth muscle differentiation. There are two main types of smooth muscle tumour: the benign leiomyoma and the malignant leiomyosarcoma.