| Myxoma | |
|---|---|
 | |
| Micrograph of anatrial myxoma.H&E stain. | |
| Specialty | Oncology  |
Amyxoma (New Latin fromGreekmuxa 'mucus') is amyxoid tumor of primitiveconnective tissue.[1] It is most commonly found in the heart (and is the most common primary tumor of theheart in adults) but can also occur in other locations.
Table below:[2]
| Myxoma | Margin | Vascular pattern | Cellularity | Stroma | Staining characteristics | Recurrence rate | Image (seeHistology) |
|---|---|---|---|---|---|---|---|
| Cutaneous myxoma or Superficial angiomyxoma | Poor to moderately circumscribed, multilobular | Scattered thin-walled vessels | Moderately cellular, bland spindled andstellate cells, variable inflammatory cell infiltrate | Abundant mucin with clefts. Up to 30% have an associated epithelial component | Vimentin; variable staining withCD34,factor XIIIA, SMA1, MSA2 andS-100 | 20–30% |  |
| Intramuscular myxoma | Poorly circumscribed merges with surrounding muscle | Hypovascular variant; hypervascular variant | Hypocellular variant; hypercellular variant; bland spindle cells | Abundant mucin with cystic spaces. Hypercellular variant has strands of collagen | Vimentin; variable staining withactin,desmin, CD34 | None |  |
| Juxta-articular myxoma | Poorly circumscribed infiltrates surrounding tissue | Focally vascular | Focally hypercellular, peripheral spindle cells with occasional atypical cells and mitoses | Abundant mucin, 89% of cases contain cystic spaces lined by fibrin or collagen | Vimentin; variable staining with actin, desmin, CD34 | 34% | |
| Aggressiveangiomyxoma | Infiltrative | Uniformly distributed medium-sized blood vessels often with prominent hyalinization | Low to moderately cellular, evenly distributed round, spindled or stellate cells | Loose myxoid to focally collagenous | Vimentin, desmin, SMA1, MSA2, estrogen and progesterone receptor | 36–72% | |
| Angiomyofibroblastoma | Well circumscribed | Abundant thin-walled blood vessels | Alternating hypercellular and hypocellular areas, perivascular condensations of spindled to epithelioidstromal cells | Collagenous to edematous with minimal mucin | Vimentin, desmin, CD34, estrogen andprogesterone receptor | No recurrences reported, but rare cases of sarcomatous degeneration | |
| Superficial acral fibromyxoma | Pushing to infiltrative | Mild to moderately accentuated vasculature | Moderately cellular, spindle and stellate cells with astoriform to fascicular pattern, variable mast cells | Myxoid to collagenous | CD34,EMA[clarification needed]3,CD99 | Recurrence rare and primarily for incompletely excised lesions | |
| Neurothekeoma (Nerve sheath myxoma) | Well circumscribed, multilobular | Hypovascular | Moderately cellular, spindled cells in fascicles and whorls | Nests of cells separated by collagenous bundles | S-100, EMA3 | 47% if incompletely excised |  |
1.^ SMA,smooth muscleactin. 2.^ MSA, muscle-specificactin. 3.^ EMA,epithelial membrane antigen.
Symptoms associated with cardiac myxomas are typically due to the effect of the mass of the tumor obstructing the normal flow of blood within the chambers of the heart. Because pedunculated myxomas are somewhat mobile, symptoms may only occur when the patient is in a particular position.
Some symptoms of myxoma may be associated with the release ofinterleukin 6 (IL-6) by the myxoma.[3][4] High levels of IL-6 may be associated with a higher risk ofembolism of the myxoma.[5]
Symptoms of a cardiac myxoma include:[6]
Myxoma is a rare, benign stromal tumor of mesenchymal origin often confused with other conjunctival stromal tumors. Conjunctival myxomas are thought to originate inTenon's capsule and can masquerade asconjunctival lymphoma,lymphangioma,ocular surface squamous neoplasia (OSSN), oramelanotic melanoma.[7]
Myxomas are usually located in either theleft orright atrium of the heart; about 86 percent occur in theleft atrium.[8]
Myxomas are typicallypedunculated, with a stalk that is attached to theinteratrial septum. The most common location for attachment of the stalk is thefossa ovalis region of the interatrial septum.[9]
Anatrial myxoma may create an extraheart sound, audible toauscultation just afterS2. It is most seen onechocardiography, as a pedunculated mass that is heterogeneous in appearance. A left atrial myxoma will cause an increase inpulmonary capillary wedge pressure.[citation needed]
Thedifferential diagnosis include other cardiac tumors such aslipomas andrhabdomyomas (and rarelyteratomas). These other tumors of the heart are typically not pedunculated, however, and are more likely toinfiltrate the muscle of the heart. Cardiacmagnetic resonance imaging (MRI) can help non-invasively diagnose cardiac tumors. However, diagnosis usually requires examination of atissue sample by apathologist.[citation needed]
Myxomas are usually removed surgically. The surgeon removes the myxoma, along with at least 5 surrounding millimeters of atrial septum. The septum is then repaired, using material from thepericardium.[citation needed]
Cardiac myxomas predominantly appear in females in their 30s to 40s. Myxomas are the most common primary cardiac tumor affecting adults,[9] accounting for one quarter to half of primary cardiac tumors seen in clinical practice.[10]