Unusual Presentation of Atrial Myxoma: A Case Report and Review of the Literature

Abstract

BACKGROUND Although rare, atrial myxoma is the most common benign cardiac tumor. The recognized triad of presenting symptoms relates to constitutional, embolic, and obstructive effects produced by the tumor. However, the presentation may be non-specific and mimic other diseases, confounding diagnosis. CASE REPORT A middle-aged woman presented with wheezing and shortness of breath. With a strong background smoking history, the initial impression was that of acute bronchospasm. She however deteriorated rapidly, with decreased consciousness and cardiac arrest requiring resuscitation. Despite intensive care management, she died within 1 day of admission. Autopsy revealed a previously undiagnosed left atrial myxoma with coronary and systemic embolization. CONCLUSIONS This case highlights an unusual presentation of atrial myxoma, resulting in fatal simultaneous embolization to the coronary and cerebral arteries. This simultaneous embolic presentation is not common, but the potential consequences are serious. This report also demonstrates that the presentation of a left-sided atrial myxoma with cardiac asthma can mimic respiratory disease and confound diagnosis. In adult patients without a history of chronic respiratory disease, the possibility of cardiac asthma should always be entertained. Furthermore, the importance of considering atrial myxoma as a cause for cardiac asthma is emphasized. The use of transthoracic echocardiogram in aiding the rapid diagnosis of atrial myxoma is recommended. Finally, the continued acknowledgement of the important contribution the academic autopsy makes in complementing and improving clinical practice remains imperative.

Figure 1.

Supine chest X-ray demonstrating bilateral interstitial infiltrates and fluid in the horizontal fissure.

Figure 2.

(A) Superior view of opened left atrium showing myxoma. (B) Formalin-fixed atrial myxoma with overlying thrombus (top), myxoid variegated areas (right), and attachment to atrial septum (bottom). (C) Myocardial-atrial myxoma interface showing tumor cells within a myxoid matrix (bottom) (H&E, ×40). (D) Sparse spindled myxoma cells in a loose eosinophilic matrix, chronic mononuclear inflammation, and hemosiderin in macrophages (H&E, ×200). Inset: Calretinin immunohistochemistry demonstrating positive tumor cells with perivascular accentuation (×100).

Figure 3.

(A) ‘Doughnut’ sections of heart showing tan areas (*) of acute infarction in the left ventricular wall. (B) Loss of left ventricular myocyte nuclei, neutrophilic infiltration, and contraction band necrosis (H&E, ×200). (C) Intramural branch of left coronary artery containing tumor embolus (H&E, ×100). (D) Positive calretinin immunohistochemistry of myxoma cells within tumor embolus (×200).

Figure 4.

(A) Lateral view of impacted tumor embolus at right common carotid artery bifurcation. (B) Carotid artery tumor fragment (*) with surrounding thrombus (H&E, ×20). (C) Higher magnification of B (H&E, ×100). (D) Calretinin immunohistochemistry highlighting tumor cells (×100).

Figure 5.

(A) Cerebral artery thromboembolus (H&E, ×20). (B) Cortex in territory of occluded cerebral artery with no signs of ischemic injury (H&E, ×40). (C) Cerebral artery thromboembolus with spindle cells (H&E, ×100). (D) Calretinin immunohistochemistry confirming myxoma cells (×100).