Uterine fibroids are not simple tumors; they come in a number of specific types.
1. Cell-rich smooth muscle tumor
The gross view is indistinguishable from that of the common type of smooth muscle tumor. The tumor seen under light microscopy has abundant smooth muscle cells, densely arranged, lacking fibrous tissue, and significantly reduced blood vessels. The tumor cells have relatively reduced cytoplasm, but still have the characteristics of smooth muscle cells spindle-shaped, rod-shaped nuclei with blunt ends, and the cells are more uniform in size and morphology. There is no anisotropy or only a few cells have anisotropy. Occasionally see nuclear division, is benign, easy to identify under the light microscope.
2.Highly schizophrenic smooth muscle tumor
The difference with ordinary uterine smooth muscle tumor is that there are more nuclear schizophrenic images under the microscope, and the number of nuclear schizophrenic images increases to 5-15/10HPF, but there is no abnormal nuclear division, no necrosis of tumor cells, excessive cells, cellular pleomorphism, interstitial changes or giant cells.
3.Odd type smooth muscle tumor or atypical smooth muscle tumor
There is no difference between the gross specimen and common smooth muscle tumor, only the microscopic presentation is different. The tumor cells are polygonal or round with visible pleomorphism, large and densely stained nuclei, and multinucleated giant cells, but with minimal nuclear schizophrenia, 0 to 1 per 10 HPF. During pregnancy or taking high doses of progesterone, the leiomyosarcoma can appear similar to the chimeric cells.
4.Vascular type smooth muscle tumor
Macroscopic examination of the tumor resembles common leiomyosarcoma with redder cut surface color. Microscopically, it can be seen that the tissues are highly edematous, there is thrombosis in small veins within the tumor, blood vessels are dilated and congested, there is extensive bleeding and hemolysis, the myocytes are lightly stained, the outline is unclear, the myocytes are reduced, the nuclei often dissolve and disappear, and there are more fat globules deposited.
5.Epithelioid smooth muscle tumor
It is a rare kind of uterine fibroid. The tumor cells are round or polygonal in shape instead of the usual smooth muscle tumor cells, and are arranged in groups or cords similar to epithelial cells, hence the name. Smooth muscle tumors are diagnosed as epithelioid smooth muscle tumors when they are composed of some or all of these cells.
Smooth myoblast-type cells are polygonal or round smooth muscle cells with abundant cytoplasm, unequal amounts of eosinophilic granules, a clear halo around the nucleus, and a round or ovoid nucleus located in the center of the cell, which is similar to embryonic smooth muscle cells, hence the name smooth muscle cell tumor. These cells are often interspersed with typical smooth muscle cells and a transitional pattern of the two types of cells can be seen.
Clear cell epithelioid smooth muscle tumors are large, well-defined, round or polygonal cells with abundant cytoplasm, hyaline and vacuolated nuclei, and centered or marginal nuclei. The lesions may be focally distributed or involve the entire myoma. Migratory transitions of smooth muscle cells are seen in the tumor. The clear cell type is rarely malignant.
Plexiform tumors are very rare, small in size, and are most often found incidentally during microscopic examination, and in recent years ultrastructure has determined their origin to be smooth muscle cells. They are mostly located in the muscular layer, and a few can also occur in the submucosa or subplasma membrane. Microscopically, one to three layers of small cells are seen closely arranged in straight or branching bundles of cord-like cells, with more abundant hyaline degenerated collagen tissue between the cells and scattered capillaries visible between them. The individual cells are small polygonal with a small amount of eosinophilic cytoplasm, small deep-stained or vesicular nuclei, small nucleoli, consistent tumor cell morphology, no pleomorphism or heterogeneity, no nuclear schizophrenia, benign, and no metastasis or recurrence.
6.Intraventricular smooth muscle tumor disease
It is a kind of tumor that grows from uterine fibroids into the vasculature or protrudes into the lumen of the vasculature after the proliferation of smooth muscle tissue in the wall of the vasculature itself. Endovenous smooth muscle disease can extend beyond the uterus and, if not completely removed, can extend within the vein along the vein to the inferior vena cava and even to the heart (very rarely).
The vast majority of patients have concurrent uterine fibroids or a past history of fibroid surgery. There are no specific clinical symptoms, there may be excessive menstruation or abdominal masses, and the uterus is enlarged on examination, which is usually not easily diagnosed before surgery. Ultrasound shows multiple nodules and rich blood supply in the tumor, which is the sonographic feature of smooth muscle tumor in the uterine vasculature and is valuable for preoperative diagnosis. If you see a special vein pattern or dark red nodules on the surface of the uterus, or nodules or dark purple masses in the broad ligament, or thickened and hardened veins in the vesicoureteral reflex, parametrial veins, and ovarian veins to palpation during surgery, you should be alert. The lesions are mainly in the myometrial wall or pelvic veins. Multiple grayish-white nodules of different sizes 0.1-2 cm can be seen in the myometrial wall section, surrounded by obvious luminal spaces, which are enlarged vasculature, and the tumors in the luminal spaces can be separated and seen to have tissues attached to the walls, which are worm-like, cord-like and branch-like, leaving a round luminal space with smooth inner wall after removal; they can also be found at the edge of intermuscular myoma or at the root of submucosal myoma. The tumor appears to be embolus-like and protrudes into the vasculature. Smooth muscle tumor in the pelvic vein outside the uterus can be seen as nodules in the broad ligament, and there are striated masses in the parametrial or ovarian veins.
7.Disseminated peritoneal smooth muscle tumor disease
Rarely, in recent years, domestic reports have been seen. It is characterized by multiple smooth muscle tumor nodules spread in the peritoneum, greater omentum, mesentery, uterine rectal recess and the surface of pelvic and abdominal organs, such as bladder, uterus, ovaries, intestinal canal, liver peritoneum, etc. The nodules are gray-white, solid, varying in size from 1-8 mm in small ones to 8 cm or larger ones, resembling the implantation of malignant tumors. Most of them are found at the time of surgery. The tumor is benign with no infiltration or destruction of surrounding tissues. Microscopic nodules consist of spindle-shaped smooth muscle cells with intertwined muscle bundles in a swirling arrangement, tumor cells of uniform size, no heterotypy, no giant cells, round nuclei or long nuclei with bluntly rounded ends, no nuclear division or occasionally seen, no vascular invasion, histology is benign.
8.Benign metastatic smooth muscle tumor
Patients with uterine smooth muscle tumor with lung or lymph node metastasis. There has been debate about benign metastases from uterine smooth muscle tumors, and in recent years it is believed that in rare cases, benign uterine smooth muscle tumors without nuclear schwannoma or with only minimal nuclear schwannoma can spread to the pelvis or retroperitoneal lymph nodes or lungs, and in some patients lung metastases occur several years after benign uterine fibroid surgery.
So many strange types make uterine fibroids no longer common and should raise a warning: it is not okay if you are menopausal, but it is important to watch closely for early detection of these specific types.