Malignancy least likely to metastasize to the heart – Correct answer: d) Prostate
Malignancy invading heart: More aggressive ones like those from breast, lung, hematological malignancies and melanoma are more likely to metastasise to heart. Slow growing tumours like carcinoma prostate is very unlikely to metastasise to the heart . Primary tumours of the heart are much less common (0.01% and 0.1%) than secondaries (0.7% and 3.5%) .
Different ways of spreading of metastases to heart:
Direct extension: Carcinoma lung
Hematogenous spread: Melanoma, lymphoma. Generally leads to myocardial or endocardial metastasis.
Retrograde lymphatic spread: Carcinoma breast. Lymphatic spread leads to pericardial and epicardial involvement.
Extension through the veins: Renal cell carcinoma – grows through renal vein into inferior vena cava and right atrium. Often mistaken for right atrial myxoma on echocardiography.
Most common metastases are from lung cancer (36 – 39%), with those from breast cancer being 10-12% and those from hematological malignancies 10-21%.
Maleszewski JJ, Bois MC, Bois JP, Young PM, Stulak JM, Klarich KW. Neoplasia and the Heart: Pathological Review of Effects With Clinical and Radiological Correlation. J Am Coll Cardiol. 2018 Jul 10;72(2):202-227.