A benign tumor is a mass of cells (tumor) that does not invade neighboring tissue or metastasize. Compared to malignant (cancerous) tumors, benign tumors generally have a slower growth rate. Benign tumors have relatively well differentiated cells. They are often surrounded by an outer surface or stay contained within the epithelium. Common examples of benign tumors include moles and uterine fibroids.
Liposarcomas are the most common subtype of soft tissue sarcomas, accounting for at least 20% of all sarcomas in adults. Soft tissue sarcomas are rare neoplasms with over 150 different histological subtypes or forms. Liposarcomas arise from the precursor lipoblasts of the adipocytes in adipose tissues. Adipose tissues are distributed throughout the body, including such sites as the deep and more superficial layers of subcutaneous tissues as well as in less surgically accessible sites like the retroperitoneum and visceral fat inside the abdominal cavity.
Uterine fibroids, also known as uterine leiomyomas or fibroids, are benign smooth muscle tumors of the uterus. Most women with fibroids have no symptoms while others may have painful or heavy periods. If large enough, they may push on the bladder, causing a frequent need to urinate. They may also cause pain during penetrative sex or lower back pain. A woman can have one uterine fibroid or many. Occasionally, fibroids may make it difficult to become pregnant, although this is uncommon.
Myomectomy, sometimes also called fibroidectomy, refers to the surgical removal of uterine leiomyomas, also known as fibroids. In contrast to a hysterectomy, the uterus remains preserved and the woman retains her reproductive potential. It still may impact hormonal regulation and the menstrual cycle.
A myoma is a type of tumor that involves muscle cells. There are two main types of myoma:
A leiomyosarcoma, also known as LMS, is a rare malignant (cancerous) smooth muscle tumor. The origin of the word is from leio- + myo- + sarcoma which means malignant smooth muscle tumor. The stomach, bladder, uterus, blood vessels, and intestines are examples of hollow organs made up of smooth muscles where LMS can be located; however, the uterus or abdomen are the most common sites.
Uterine artery embolization is a procedure in which an interventional radiologist uses a catheter to deliver small particles that block the blood supply to the uterine body. The procedure is primarily done for the treatment of uterine fibroids and adenomyosis. Since uterine fibroids are the most common indication, it is also often referred to as uterine fibroid embolization. Compared to surgical treatment for fibroids such as a hysterectomy, in which a woman's uterus is removed, uterine artery embolization may be beneficial in women who wish to retain their uterus. Other reasons for uterine artery embolization are postpartum hemorrhage and uterine arteriovenous malformations.
Adenomyoma is a tumor (-oma) including components derived from glands (adeno-) and muscle (-my-). It is a type of complex and mixed tumor, and several variants have been described in the medical literature. Uterine adenomyoma, the localized form of uterine adenomyosis, is a tumor composed of endometrial gland tissue and smooth muscle in the myometrium. Adenomyomas containing endometrial glands are also found outside of the uterus, most commonly on the uterine adnexa but can also develop at distant sites outside of the pelvis. Gallbladder adenomyoma, the localized form of adenomyomatosis, is a polypoid tumor in the gallbladder composed of hyperplastic mucosal epithelium and muscularis propria.
The uterine sarcomas form a group of malignant tumors that arises from the smooth muscle or connective tissue of the uterus.
Genital leiomyomas are leiomyomas that originate in the dartos muscles, or smooth muscles, of the genitalia, areola, and nipple. They are a subtype of cutaneous leiomyomas that affect smooth muscle found in the scrotum, labia, or nipple. They are benign tumors, but may cause pain and discomfort to patients. Genital leiomyoma can be symptomatic or asymptomatic and is dependent on the type of leiomyoma. In most cases, pain in the affected area or region is most common. For vaginal leiomyoma, vaginal bleeding and pain may occur. Uterine leiomyoma may exhibit pain in the area as well as painful bowel movement and/or sexual intercourse. Nipple pain, enlargement, and tenderness can be a symptom of nipple-areolar leiomyomas. Genital leiomyomas can be caused by multiple factors, one can be genetic mutations that affect hormones such as estrogen and progesterone. Moreover, risk factors to the development of genital leiomyomas include age, race, and gender. Ultrasound and imaging procedures are used to diagnose genital leiomyomas, while surgically removing the tumor is the most common treatment of these diseases. Case studies for nipple areolar, scrotal, and uterine leiomyoma were used, since there were not enough secondary resources to provide more evidence.
Fibrous hamartoma of infancy (FHI) is a rare, typically painless, benign tumor that develops in the subcutaneous tissues of the axilla, arms, external genitalia, or, less commonly, various other areas. It is diagnosed in children who are usually less than 2 years old or, in up to 20% of cases, develops in utero and is diagnosed in an infant at birth.
Benign lipoblastomatosis is a tumor consisting of fetal-embryonal adipocytes, frequently confused with a liposarcoma, affecting exclusively infants and young children, with approximately 90% of cases occurring before 3 years of age. The term lipoblastomatosis was first used by Vellios et al. in 1958, at which point the tumor became generally accepted as a distinctive entity. Today Diffuse lipoblastoma is the preferred term for lipoblastomatosis. The tumor is rare, accounting for less than 1% of all childhood neoplasm, and it has been found to be more common in males than females. It often presents as an asymptomatic rapidly enlarging mass, occurring more often in the soft tissues of the extremities.
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.
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.
Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) or Reed's syndrome is rare autosomal dominant disorder associated with benign smooth muscle tumors and an increased risk of renal cell carcinoma. It is characterised by multiple cutaneous leiomyomas and, in women, uterine leiomyomas. It predisposes for renal cell cancer, an association denominated hereditary leiomyomatosis and renal cell cancer, and it is also associated with increased risk of uterine leiomyosarcoma. The syndrome is caused by a mutation in the fumarate hydratase gene, which leads to an accumulation of fumarate. The inheritance pattern is autosomal dominant and screening can typically begin in childhood.
A morcellator is a surgical instrument used for division and removal of large masses of tissues during laparoscopic surgery. In laparoscopic hysterectomy the uterus is cut up in strips, or morcellated, into smaller pieces inside the patient's abdominal cavity in order to extract from the abdomen. It can consist of a hollow cylinder that penetrates the abdominal wall, ending with sharp edges or cutting jaws, through which a grasper can be inserted to pull the mass into the cylinder to cut out an extractable piece.
Proliferative fasciitis and proliferative myositis (PF/PM) are rare benign soft tissue lesions that increase in size over several weeks and often regress over the ensuing 1–3 months. The lesions in PF/PM are typically obvious tumors or swellings. Historically, many studies had grouped the two descriptive forms of PF/PM as similar disorders with the exception that proliferative fasciitis occurs in subcutaneous tissues while proliferative myositis occurs in muscle tissues. In 2020, the World Health Organization agreed with this view and defined these lesions as virtually identical disorders termed proliferative fasciitis/proliferative myositis or proliferative fasciitis and proliferative myositis. The Organization also classified them as one of the various forms of the fibroblastic and myofibroblastic tumors.
Fibroblastic and myofibroblastic tumors (FMTs) develop from the mesenchymal stem cells which differentiate into fibroblasts and/or the myocytes/myoblasts that differentiate into muscle cells. FMTs are a heterogeneous group of soft tissue neoplasms. The World Health Organization (2020) defined tumors as being FMTs based on their morphology and, more importantly, newly discovered abnormalities in the expression levels of key gene products made by these tumors' neoplastic cells. Histopathologically, FMTs consist of neoplastic connective tissue cells which have differented into cells that have microscopic appearances resembling fibroblasts and/or myofibroblasts. The fibroblastic cells are characterized as spindle-shaped cells with inconspicuous nucleoli that express vimentin, an intracellular protein typically found in mesenchymal cells, and CD34, a cell surface membrane glycoprotein. Myofibroblastic cells are plumper with more abundant cytoplasm and more prominent nucleoli; they express smooth muscle marker proteins such as smooth muscle actins, desmin, and caldesmon. The World Health Organization further classified FMTs into four tumor forms based on their varying levels of aggressiveness: benign, intermediate, intermediate, and malignant.
Angiofibroma of soft tissue (AFST), also termed angiofibroma, not otherwise specified, is a recently recognized and rare disorder that was classified in the category of benign fibroblastic and myofibroblastic tumors by the World Health Organization in 2020. An AFST tumor is a neoplasm that was first described by A. Mariño-Enríquez and C.D. Fletcher in 2012.
