Meaning of alveolar rhabdomyosarcoma: Alveolar rhabdomyosarcoma is a muscle related soft tissue cancer that tends to affect older children and adolescents and behaves more aggressively than the embryonal subtype.

Definition of alveolar rhabdomyosarcoma

Alveolar rhabdomyosarcoma is a subtype of rhabdomyosarcoma, a soft tissue cancer arising from cells related to skeletal muscle. Its name refers to the pattern its cells form under the microscope, which resembles the small air sacs, or alveoli, found in the lung, though the tumor itself has no relationship to the lungs.

This subtype tends to occur more often in older children, adolescents, and young adults compared with embryonal rhabdomyosarcoma, the other major subtype, which more typically affects younger children, and alveolar rhabdomyosarcoma commonly arises in the trunk, arms, or legs. Many cases are associated with a characteristic chromosomal rearrangement that fuses two genes together, a molecular feature used to help confirm the diagnosis.

Alveolar rhabdomyosarcoma generally behaves more aggressively than the embryonal subtype, with a greater tendency to spread to other parts of the body, which is why identifying the specific subtype is an important part of planning treatment.

Also known as

ARMS

Used in a sentence

Biopsy of the mass confirmed alveolar rhabdomyosarcoma in the adolescent patient.

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Good to know

Alveolar rhabdomyosarcoma behaves more aggressively than the embryonal subtype of rhabdomyosarcoma, so identifying which subtype is present meaningfully affects how the cancer is evaluated and treated.

Word origin

Where “alveolar rhabdomyosarcoma” comes from

Formed from Latin alveolus, meaning a small cavity, describing the microscopic pattern of the tumor cells; rhabdomyosarcoma combines Greek rhabdos, meaning rod, myos, meaning muscle, and sarx, meaning flesh.

For learning, not diagnosis. This glossary provides general educational information and is not a substitute for advice from a qualified healthcare professional. If you may be experiencing a medical emergency, contact local emergency services.