Leiomyoma

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Surgical specimen of a leiomyoma of the uterus.

Leiomyomas are benign ( benign ) tumors of smooth muscle .

pathology

Leiomyoma histology. Hematoxylin-eosin stained section.

Smooth muscles are formed from mesenchymal cells during the development of a living being . The leiomyomas are therefore also assigned to the large group of benign mesenchymal tumors. The most common localization of leiomyomas in humans is the uterus , accounting for around 90% of cases; such tumors are known as uterine fibroids . In addition, leiomyomas can develop in all organs that have parts of smooth muscles, such as leiomyomas of the vessels (angioleiomyomas), the skin appendages (dermatoleiomyomas), the esophagus (esophageal leiomyomas ) and the urinary tract . Also intracranial leiomyomas described in individual cases.

Classification

Vaginal leiomyoma in a female dog

According to the WHO classification of soft tissue tumors, leiomyomas are classified as smooth muscle tumors in the main group of fibrohistiocytic tumors. A distinction is made between:

  • Angioleiomyomas: relatively more common, predominantly in the extremities (more often in the lower extremities), often painful tumor in the subcutaneous tissue. Rarely larger than 2 cm. Local pruning is sufficient.
  • deep soft tissue leiomyomas: a rare type of leiomyoma in deeper tissue layers. Mainly in the skeletal muscle (there the same frequency in both sexes), but can also be found retroperitoneally (there in women significantly more often). Complete resection recommended; recurrences are common.
  • genital leiomyomas
  • Soft tissue leiomyosarcomas : malignant variant of leiomyomas. Mostly in middle to older age. Often in the retroperitoneum and pelvic area (significantly more common in both locations in women), but also originating from large vessels. About 10–15% of extremity sarcomas are also leiomyosarcomas. Distant metastases and local recurrences are common. At diagnosis, retroperitoneal leiomyosarcomas are usually very large, with no clearly defined border, and can rarely be completely removed, so the prognosis is relatively poor.

Other special forms in soft tissue are pilar leiomyomas, cutaneous leiomyosarcomas, leiomyomatosis peritonealis disseminata, and epithelioid leiomyomas of the smooth muscles. In recent years, forms of leiomyoma have been increasingly described in immunocompromised patients (e.g. HIV patients and transplant recipients), with an association with the Epstein-Barr virus .

In addition, the WHO classifies two types of bone tumors:

  • Bone leiomyoma: very rare, benign bone tumor, especially in middle age. Most often in the facial bones, mostly in the lower jaw. Painful radiolucent tumors, rarely larger than 3 cm. Local resection is sufficient.
  • Leiomyosarcoma of the bone: rare, very malignant tumor, usually in middle age. Predominantly close to the knees on the thighbone ( femur ) or shinbone ( tibia ). The next most common location is the facial skull. Rarely larger than 6 cm, often infiltrating through the corticalis into the surrounding tissue. In about half of the cases, distant metastases arise predominantly in the lungs. Mortality about 50%.

See also

literature

  • W. Böcker among others: Pathology. 3. Edition. Urban & Fischer-Verlag, 2004, ISBN 3-437-42381-9 .

Individual evidence

  1. ↑ PH Lai et al .: Primary intracranial leiomyoma: case report. In: Neuroradiology. 40 (4), 1998, pp. 238-241. PMID 9592794
  2. ↑ CDM Fletcher, KK Unni, F. Mertens: Pathology Genetics: Tumors of Soft Tissue and Bone. World Health Organization Classification of Tumors. IARC Press, Lyon 2002, ISBN 92-832-2413-2 .