Cardiac tumors

Cardiac Tumors - An Overview

• Primary Tumors: Rare overall. Benign are more common than malignant.
  • Benign (most frequent primary type):
    • Adults: Atrial Myxoma. Typically in the left atrium. Can cause a "ball-valve" obstruction, leading to syncope or embolic strokes.
    • Children: Rhabdomyoma. Strongly associated with Tuberous Sclerosis.
  • Malignant: Angiosarcoma is the most common.
• Metastatic Tumors: Spread from another primary site.
  • Common sources: Melanoma, lung cancer, breast cancer, and lymphoma.

⭐ Metastatic tumors are 20-40 times more common than primary cardiac tumors.

Atrial Myxoma - The Classic Ball‑Valve

• Most common primary cardiac tumor in adults; ~90% arise in the atria (LA > RA), often attached to the fossa ovalis.
• Clinical Features:
  • "Ball-valve" obstruction: A pedunculated mass flops into the mitral valve during diastole, causing syncope, dyspnea, and mimicking mitral stenosis.
  • Constitutional symptoms: Fever, weight loss, and malaise due to cytokine production (esp. IL-6).
  • Auscultation: Characteristic early diastolic "tumor plop".
• Histology: Composed of scattered stellate-shaped myxoma cells suspended in a gelatinous myxoid stroma (abundant mucopolysaccharide ground substance).
• Complications: High risk of systemic embolization, leading to stroke or other infarcts.

⭐ Associated with Carney Complex, an autosomal dominant syndrome featuring multiple myxomas (cardiac, skin), spotty pigmentation (lentigines), and endocrine tumors.

Other Tumors - Rhabdomas & Rascals

• Cardiac Rhabdomyoma
  • Benign hamartoma; the most common primary heart tumor in infants and children.
  • Location: Often multiple, favoring the ventricular walls and septum.
  • Clinical: May cause outflow obstruction, arrhythmias, or be asymptomatic.
  • Histo: Pathognomonic large, polygonal “spider cells” (glycogen-filled vacuoles with cytoplasmic strands).
  • Prognosis: Most spontaneously regress; surgery only if symptomatic.

⭐ Over 50% of cases are associated with Tuberous Sclerosis (TSC1/TSC2 gene mutations).

Clinical Picture - Diagnosis & Effects

• Presentation: Highly variable; depends on tumor size, location, and mobility.
  • Systemic/Constitutional: Fever, weight loss, malaise (cytokine release, esp. myxoma).
  • Obstructive: Mimics valve stenosis. Syncope, dyspnea, heart failure from mass effect.
  • Embolic: Tumor fragments break off → stroke, MI, limb ischemia.
  • Arrhythmias: Conduction system invasion → palpitations, heart block.

⭐ Left atrial myxomas classically cause a "ball-valve" obstruction, leading to syncope, and can present with stroke-like symptoms from systemic embolization.

High‑Yield Points - ⚡ Biggest Takeaways

• Metastases are the most common cardiac tumors, far more than primary tumors.
• Myxoma is the most common primary adult tumor, typically in the left atrium, causing "ball-valve" obstruction and constitutional symptoms (IL-6).
• Rhabdomyoma is the most frequent primary pediatric tumor, strongly associated with tuberous sclerosis.
• Angiosarcoma is the most common primary malignant cardiac tumor.
• Common sources of metastases include melanoma, lung, and breast cancer.