Full Answer
What is a muscle tumor called?
Myomas are tumors that grow from muscle. Leiomyomas grow from smooth muscle, which is found in internal organs such as the stomach and uterus. They can start in the walls of blood vessels. In the wall of the uterus, leiomyomas are often called fibroids. A rare benign tumor of skeletal muscle is rhabdomyoma.
How are benign smooth muscle tumors (leiomyomas) classified?
For purposes of classification, these tumors can be divided into several groups. Cutaneous leiomyomas (leiomyoma cutis) are the most common group of benign smooth muscle tumors, with two types. Those arising from the pilar arrector muscles of the skin are often multiple and associated with significant pain.
Which smooth muscle tumors show differentiation towards smooth muscle?
Tumors showing differentiation towards smooth muscle include hamartomas, benign tumors, and malignant tumors. Objective: This review article describes the clinical presentation and course, histology, and treatment recommendations for benign and malignant smooth muscle tumors.
How are tumors of soft tissue tumors classified?
Background: In the classification of tumors of soft tissue, modern schemes describe tumors by the normal adult tissue type the tumor resembles. Thus, tumors are described as smooth muscle tumors if the cells are differentiating towards smooth muscle.
What are benign smooth muscle tumors called?
Benign smooth muscle tumors include smooth muscle hamartoma and angioleiomyoma. A specific category of leiomyomas are estrogen-receptor positive ones in women. These are similar to uterine leiomyomas and can occur anywhere in the abdomen and abdominal wall.
What is a benign tumor of skeletal muscle?
Rhabdomyomas are benign tumors of skeletal muscle and are very rare. Benign Tumors of Peripheral Nerve Tissue (Benign Peripheral Nerve Sheath Tumors) Neurofibromas, schwannomas (neurilemmomas), and neuromas are benign tumors of nerves. These tumors can occur almost anywhere in the body.
What is the term describing a benign tumor of smooth muscle origin in the uterus?
A benign smooth muscle tumor, usually in the uterus or gastrointestinal tract. Also called fibroid.
What is a smooth muscle neoplasm?
Definition. Uterine smooth muscle tumors are neoplasms composed of smooth muscle; they range from benign leiomyomas to low-grade and high-grade leiomyosarcomas. Several histologic subtypes exist, including usual (spindled), epithelioid, and myxoid tumors.
What is a muscle tumor called?
Soft tissue sarcoma is a rare type of cancer that begins in the tissues that connect, support and surround other body structures. This includes muscle, fat, blood vessels, nerves, tendons and the lining of your joints.
What is tumor of skeletal muscle called?
Rhabdomyosarcoma (RMS) is the medical term for a type of cancer which originates in cells (called rhabdomyoblasts) that develop into skeletal muscles.
Is leiomyoma a benign tumor?
Leiomyomas are benign tumors arising from smooth muscle, most commonly seen in uterine myometrium, gastrointestinal tract, skin and lower extremities of middle-aged women.
Are benign tumors of the smooth muscle of the uterus?
Uterine fibroids (leiomyomas) are benign tumors that exhibit various forms of smooth muscle differentiation. The classic (conventional or typical) spindled form of leiomyoma is the most common pelvic tumor in females [1-3].
What is the difference between leiomyoma and leiomyosarcoma?
Leiomyomas are benign , smooth muscle tumors arising from the uterine myometrium, whereas leiomyosarcomas are aggressive, malignant tumors of the myometrium.
Is hamartoma benign or malignant?
A hamartoma is a local malformation made up of an abnormal mixture of cells and tissue. Although most hamartomas are benign, they cause morbidity by various mechanisms such as; infection, infarction, pressure/obstruction, hemorrhage/anemia, fracture, neoplastic transformation.
Which of the following tumor originates from smooth muscles?
Leiomyosarcoma, or LMS, is a type of rare cancer that grows in the smooth muscles.
What is the difference between sarcoma and leiomyosarcoma?
Soft tissue sarcoma is usually classified based on where in the body the cancer started: If sarcoma starts in smooth muscle, it is called leiomyosarcoma. Gastrointestinal tract sarcoma is called a gastrointestinal stromal tumor. Soft tissue sarcoma in fatty tissue (also called adipose tissue) is called liposarcoma.
What is the benign tumor of skeletal muscle called quizlet?
Rhabdomyoma is a benign tumor of striated muscle; rhabdomyosarcoma is a malignant tumor of striated muscle tissue.
What benign tumors are most common?
Lipomas: Lipomas are formed by fat cells. They are the most common type of benign tumor. Meningiomas: These tumors develop in the brain and spinal cord membranes and are most commonly benign.
What is a schwannoma tumor?
Schwannoma is a rare type of tumor that forms in the nervous system. Schwannoma grows from cells called Schwann cells. Schwann cells protect and support the nerve cells of the nervous system. Schwannoma tumors are often benign, which means they are not cancer. But, in rare cases, they can become cancer.
What causes benign tumors?
The exact cause of a benign tumor is often unknown. It develops when cells in the body divide and grow at an excessive rate. Typically, the body is able to balance cell growth and division. When old or damaged cells die, they are automatically replaced with new, healthy cells.
What is the smooth muscle phenotype of cutaneous leiomyomas?
On immunohistochemistry (IHC), cutaneous leiomyomas show a “complete” smooth muscle phenotype, with coexpression of smooth muscle actins, desmin, and h-caldesmon (see Fig. 15.3 ). IHC for fumarate hydratase (FH) and 2-succinocysteine (2SC) have been shown to be extremely valuable in the identification of patients with possible HLRCC, and correlate well with the presence of FH gene mutations. In HLRCC, FH mutation results in loss of expression of FH and accumulation of 2SC. Buelow et al. recently showed that 11 cutaneous leiomyomas with known FH mutations were positive for 2SC, with 6 of 11 also showing loss of FH expression ( Fig. 15.5B ). They also identified FH mutations on IHC in rare patients presenting with solitary cutaneous leiomyomas and suggested that these be performed on all patients with cutaneous leiomyomas to identify potential HLRCC kindreds. Similar findings have also been reported in uterine leiomyomas and renal cell carcinomas from patients with FH mutation.
Where are smooth muscle cells located?
Smooth muscle cells are fusiform in shape and have centrally located cylindrical nuclei with round ends that develop deep indentations during contraction. The length of the muscle cell varies depending on the organ, achieving its greatest length in the gravid uterus, where it may measure as much as 0.5 mm. The cells are usually arranged in fascicles where the nuclei are staggered so that the tapered end of one cell lies in close association with the thick nuclear region of an adjacent cell. Typically, there are no connective tissue cells between individual muscle fibers, although a delicate basal lamina and small connective tissue fibers, presumably synthesized by the muscle cells, can be seen as a thin, periodic acid–Schiff (PAS)–positive rim around individual cells in light microscopy preparations.
What are the characteristics of angiomyoma?
Microscopically, the tumors have a characteristic appearance that varies little from case to case. The usual appearance is a well-demarcated nodule of smooth muscle tissue punctuated with thick-walled vessels with partially patent lumens ( Figs. 15.6 to Fig 15.9 ). Typically, the inner layers of smooth muscle of the vessel are arranged in an orderly circumferential fashion, and the outer layers spin or swirl away from the vessel, merging with the less well-ordered peripheral muscle fibers. The morphologic features of angiomyoma overlap to a degree with those of myopericytoma , and the distinction between these two entities may be quite subjective (see Chapter 24 ). Areas of myxoid change ( Fig. 15.8 ), hyalinization, calcification, and fat may be seen. The vessels in these tumors are difficult to classify because they are not typical of veins or arteries. Their thick walls and small lumens are reminiscent of arteries, but they consistently lack internal and external elastic laminae. In the experience of Hachisuga, a small number of angiomyomas are composed of predominantly cavernous-type vessels. Nerve fibers are usually difficult to demonstrate but undoubtedly are present, accounting for the exquisite sensitivity of these lesions to manipulation. Rarely, angiomyomas display degenerative nuclear atypia similar to that seen in symplastic leiomyomas. Angiomyoma is a benign tumor, causing few problems apart from pain. Simple excision is adequate. None of the patients reported by Duhig and Ayer developed recurrence after excision. In the Hachisuga series, only two patients had a recurrence, although their follow-up data were incomplete.
What is the gene for cutaneous leiomyomas?
Recent evidence suggests that the majority of patients presenting with multiple cutaneous leiomyomas have germline mutations of the fumarate hydratase gene, mapped to chromosome 1q43 and encoding an enzyme in the Krebs cycle. This disease also predisposes to early-onset uterine leiomyomas in women and to early-onset renal cell carcinoma of the collecting duct and papillary type in both men and women, termed hereditary leiomyomatosis and renal cell cancer (HLRCC). However, sporadic leiomyomas and leiomyosarcomas seemingly do not typically harbor somatic mutations of this gene. The prevalence of HLRCC is unknown, and it has been reported in approximately 200 families worldwide. The penetrance of HLRCC in affected families is almost 100%. HLRCC-associated cutaneous leiomyomas typically arise in young patients (mean age: 25 years), as do uterine leiomyomas (mean age: 30).
How big are pilar leiomyomas?
Most pilar leiomyomas are 1 to 2 cm in diameter. They lie in the dermal connective tissue and are separated from the overlying atrophic epidermis by a grenz zone. The lesions are less well defined than angiomyoma and blend irregularly with the surrounding dermal collagen and adjacent pilar muscle ( Figs. 15.2 and 15.3 ). The central portions of the lesions are usually devoid of connective tissue and consist exclusively of packets or bundles of smooth muscle fibers. They usually intersect in an orderly fashion and often create the impression of hyperplasia or overgrowth of the pilar arrector muscle. The cells resemble normal smooth muscle cells, and myofibrils can be easily demonstrated with special stains, such as the Masson trichrome stain, in which they appear as red linear streaks traversing the cytoplasm longitudinally. Leiomyomas associated with HLRCC often show somewhat greater nuclear atypia than do their nonsyndromic counterparts and may sometimes also show eosinophilic cytoplasmic inclusions and prominent nucleoli ( Figs. 15.4 and 15.5 ).
What is a leiomyoma?
Superficial, or cutaneous, leiomyomas are of two types. Those arising from the pilar arrector muscles of the skin may be solitary or multifocal and are often associated with considerable pain and tenderness. The other form, the genital leiomyoma, arises from the diffuse network of muscle in the deep dermis of the genital zones (e.g., scrotum, nipple, areola, vulva). In the scrotum, leiomyomas arise from the dartoic muscles (dartoic leiomyoma) and, in the nipple, from the muscularis mamillae and areolae. This form is almost always solitary and rarely causes significant pain.
How long are somatic leiomyomas alive?
The number of somatic leiomyomas with extended follow-up information is still quite small, but in the largest series reported by Billings et al., all 11 patients were alive and well from 5 to 97 months (median: 67 months) after diagnosis.
How common is a benign muscle tumor?
It is difficult to establish their prevalence, but it is estimated that benign muscle tumors make up less than 2% of all benign soft tissue tumors ( 1 ), while rhabdomyosarcoma and leiomyosarcoma account for approximately 2% to 12% and 8% to 9%, respectively, of all classified soft tissue sarcomas ( 2, 3, 4 ).
What is a vascular leiomyoma?
Vascular leiomyoma (angioleimyoma): small to moderate size lesions arising in subcutaneous tissue. Deep leiomyoma of soft tissue: large lesions in deep soft tissue. Weiss and Goldblum ( 8) also noted that leiomyomatosis peritonealis disseminata and intravenous leiomyomatosis are also classified as benign leiomyomas.
What is a rhabdomyoma?
Rhabdomyoma. Originally described in 1864 and termed rhabdomyoma purum, rhabdomyoma is a rare benign tumor composed of striated muscle cells ( 46, 47 ). Although rhabdomyomas make up approximately 2% of muscle tumors ( 47 ), only 115 extracardiac rhabdomyomas were reported in the literature through 1988 ( 48 ).
What is the second group of leiomyoma?
The second group of leiomyoma is the angioleiomyoma, also known as angiomyoma or vascular leiomyoma. This lesion is differentiated from the cutaneous form by its subcutaneous location and histology, which is dominated by a conglomeration of thick-walled vessels associated with smooth muscle tissue ( 8 ).
How big are Pilar Leiomyomas?
They typically occur as clustered papules or, less commonly, as single nodules ranging in size from a few millimeters to 2 cm ( Fig. 7.1) ( 10, 11 ). Single lesions tend to be larger ( 11 ). Pilar leiomyomas are most common in young adults, on the hair-bearing extensor surfaces of the arms and legs ( 10, 11, 12 ).
How common is angioleomyoma?
Angioleiomyoma is most common in adults, with two-thirds occurring in patients in the fourth through sixth decades of life (9), although they have been reported in children (16, 17). Women are reported to be affected more commonly than men (1.7-2.2:1) (9, 14); however, there is a male predilection (2.1:1) in the AFIP experience (1). The lesion is typically small, less than 2 cm, and located in the extremities in 89% to 94% of cases, with the lower extremity most frequently involved (approximately 50% to 75% of extremity cases) (1, 9, 14, 18). Because the foot is a common location, patients may present with complaints related to problems with footwear (19, 20). Pain and tenderness are found in more than half of the patients and may be initiated with changes in temperature, pressure, pregnancy, or menses (18, 21). Symptoms may be initiated by light touching or scratching (18). Lesions are often slowly growing and may be present for 10 to 15 years prior to presentation (19, 22).
Where is leiomyoma found?
Leiomyoma of the deep soft tissue is a lesion of adults and is typically located in the deep soft tissue of the extremities or retroperitoneum (8, 23). Billings et al. (23) reviewed their experience with 36 cases of leiomyoma seen in consultation at Emory University. These investigators confirmed that deep leiomyoma occurs in two distinct locations: the deep somatic soft tissue of the extremities (n= 13) and the retroperitoneum (n= 23; 3 of which occurred in the abdomen). They also noted that extremity lesions affected both sexes equally, whereas retroperitoneal lesions occurred almost exclusively in women (22 women, 1 man), suggesting two distinct subtypes: the deep leiomyoma of somatic soft tissue and the retroperitonealabdominal leiomyoma. This latter form likely arises from hormonally sensitive smooth muscle and is similar to uterine leiomyoma. Deep leiomyomas are usually large at presentation, suggesting that they produce few symptoms (8).
What is a tumor of the skeletal muscle called?
Myomas are tumors that grow from muscle. Leiomyomas grow from smooth muscle, which is found in internal organs such as the stomach and uterus. In the wall of the uterus, leiomyomas are often called fibroids. A rare benign tumor of skeletal muscle is rhabdomyoma. These tumors may be simply watched. To address symptoms, they may be shrunk with medication or removed with surgery.
What is the most common bone tumor?
Osteochondromas are the most common type of benign bone tumor. These tumors usually appear as a painless bump or bumps near the joint such as the knee or shoulder. Often, the doctor will simply watch this benign tumor with X-rays. Surgery may be needed if the tumor causes symptoms such as pain or pressure on nerves or blood vessels.
What is an adenoma?
Adenomas are benign tumors starting in the epithelial tissue of a gland or gland-like structure. The epithelial tissue is the thin layer of tissue covering organs, glands, and other structures. A common type of adenoma is a polyp in the colon. Adenomas might also grow in the liver or the adrenal, pituitary, or thyroid gland.
What are the two types of tumors that can be found in the nerves?
Neuromas grow from nerves. Two other types of nerve tumors are neurofibromas and schwannomas. These benign nerve tumors can occur almost anywhere in nerves that run throughout the body. Neurofibromas are more common in people with an inherited condition called neurofibromatosis. Surgery is the most common type of treatment for benign nerve tumors.
Why do fibrous tumors need to be removed?
Because they can cause symptoms, fibrous tissue tumors may need to be removed with surgery.
How many meningiomas are benign?
Meningiomas are tumors that develop from the membrane surrounding the brain and spinal cord. About nine in 10 are benign. Many grow slowly. Others grow more quickly. Treatment varies depending on the location of the meningioma and the symptoms it causes. Symptoms may include headache and weakness on one side, seizures, personality changes, and visual problems.
Where do lipomas grow?
Lipomas grow from fat cells. They are the most common benign tumor in adults, often found in the neck, shoulders, back, or arms. Lipomas are slow growing, usually round and movable, and soft to the touch. They may run in families. Treatment may be needed if a lipoma is painful or growing quickly. This may include steroid shots or removal through liposuction or surgery.
What is benign tumor?
What are benign tumors? Benign tumors are noncancerous growths in the body. Unlike cancerous tumors, they don’t spread (metastasize) to other parts of the body. Benign tumors can form anywhere.
Why do tumors grow?
It develops when cells in the body divide and grow at an excessive rate. Typically, the body is able to balance cell growth and division. When old or damaged cells die , they are automatically replaced with new, healthy cells. In the case of tumors, dead cells remain and form a growth known as a tumor.
What to do if you don't have a tumor removed?
If you don’t have your tumor removed, your doctor may have you come in for routine examinations or imaging scans to ensure that the tumor isn’t growing larger.
Why is a tumor removed?
Other tumors that affect organs, nerves, or blood vessels are commonly removed with surgery to prevent further problems.
How to tell if a tumor is close to the skin?
If the tumor is close to the skin or in an area of soft tissue such as the abdomen, the mass may be felt by touch.
What are the symptoms of brain tumors?
For example, if you have a benign brain tumor, you may experience headaches, vision trouble, and fuzzy memory.
Where do adenomas form?
Adenomas form in the thin layer of tissue that covers glands, organs, and other internal structures. Examples include polyps that form in the colon or growths on the liver. Lipomas grow from fat cells and are the most common type of benign tumor, according to the Cleveland Clinic.
What is a benign smooth muscle tumor?
Benign smooth muscle tumor (leiomyoma) of deep somatic soft tissue of the extremity: histologically, an unencapsulated, well-circumscribed, multinodular, low cellularity spindle cell lesion is usually seen (a). The lesional cells are characteristically bland, cigar-shaped spindle cells, with eosinophilic cytoplasm and indistinct cell borders. There is no evidence of mitotic activity, nuclear pleomorphism, or coagulative tumor necrosis (b). Hyalinization and calcification may be present (c). Osseous metaplasia was also seen in this particular case (d).
What is the diagnosis of leiomyoma in deep somatic soft tissue?
The diagnosis of leiomyoma in deep somatic soft tissue sites should be based on stringent histological criteria, specifically extremely low levels of, or even perhaps absence of, mitotic activity and the absence of nuclear atypia and coagulative tumor necrosis [ 10#N#S. D. Billings, A. L. Folpe, and S. W. Weiss, “Do leiomyomas of deep soft tissue exist? An analysis of highly differentiated smooth muscle tumors of deep soft tissue supporting two distinct subtypes,” American Journal of Surgical Pathology, vol. 25, no. 9, pp. 1134–1142, 2001. View at: Publisher Site | Google Scholar#N#See in References#N#]. Leiomyomas of deep somatic soft tissue diagnosed as such are expected to have an excellent outcome. It is, however, prudent to remember that these lesions are rare and are far outnumbered by their malignant counterpart; therefore, these lesions must be thoroughly sampled/all embedded and closely evaluated for the presence of cytological atypia, mitotic activity, and necrosis. The presence of low mitotic activity in otherwise differentiated smooth muscle tumors of deep somatic soft tissue without coagulative tumor necrosis should prompt a diagnosis of a smooth muscle tumor of uncertain malignant potential.
Where do leiomyomas occur?
As alluded to previously, leiomyomas of deep soft tissue segregate into two distinct clinicopathological groups, one group occurring in deep somatic soft tissue (the topic of this review) and the second occurring primarily in women in the pelvic retroperitoneum. For completeness, benign smooth muscle tumors (leiomyomas) of the pelvic retroperitoneum will be discussed briefly (Table 2 ).
What is the size of a leiomyoma?
Grossly, the majority of deep somatic soft tissue leiomyomas are circumscribed masses, with a tan-grey to white cut surface, and a mean size of 5.4 cm. Degenerative mucoid-cystic change is occasionally present [ 10.
Is leiomyoma a soft tissue tumor?
Leiomyomas of deep soft tissue are extremely rare and should only be diagnosed following adherence to stringent histological criteria, namely, the absence of nuclear atypia and of coagulative tumor necrosis. Whether extremely low counts of, or even any, mitotic activity are acceptable when making a diagnosis of leiomyoma in deep soft tissue sites is controversial. The morphology and immunophenotype of smooth muscle tumors in deep soft tissue are similar to their counterparts irrespective of topography. It is interesting to note that leiomyomas of deep soft tissue (extremity and retroperitoneum) are often hyalinized/sclerosed and calcified. However, the prediction of their behavior and correct codification is dependent on thorough, meticulous search for mitoses and necrosis. Leiomyomas of deep soft tissue in the extremity should be devoid of mitoses and “significant” cytological atypia. An occasional larger, slightly pleomorphic cell in the midst of bland spindle cells, can be regarded as insignificant atypia. If any mitotic activity and several atypical cells are encountered in smooth muscle tumors of deep soft tissue of the extremity, it would be prudent to invoke the appellation of smooth muscle tumor of uncertain malignant potential and advocate wide local excision and follow-up.
Where is the most common leiomyoma?
Angioleiomyoma. Angioleiomyoma is the most common peripheral soft tissue leiomyoma, typically occurring in the subcutis of extremities, particularly the lower leg, but also in the trunk wall and less commonly in the head and neck region .
Do smooth muscle tumors have mitotic activity?
To date, there have been very few studies of well-differentiated smooth muscle tumors of deep soft tissue that display an absence of mitotic activity and cytological atypia. It is now thought that, although they are exceptionally rare, deep soft tissue leiomyomas do in fact exist [ 1.
