Background/Objectives: Giant atrial chambers are rare but clinically important conditions, most often linked to rheumatic mitral valve disease, though they may also occur in congenital or other acquired disorders. Despite their low prevalence, they entail major hemodynamic, arrhythmogenic, and extracardiac risks. This study aimed to review recent evidence on giant atrial pathology—including giant left atrium (GLA), giant right atrium (GRA), and atrial appendage aneurysms—and to illustrate its relevance through cases of symptomatic extracardiac compression. Methods: A PubMed search on 15 September 2025 using “giant atrium” and limited to human, free full-text studies from the last 10 years yielded 93 results. After screening, 21 reports describing 24 cases were analyzed and compared with institutional experience. Results: GLA is most often defined by an anteroposterior diameter ≥6.5 cm or ≥8 cm, while criteria for GRA and appendage aneurysms remain inconsistent. Reported complications include atrial fibrillation, thromboembolism, and compression of mediastinal structures, with presentations such as dysphagia or airway obstruction. While valve surgery alone may suffice, many authors recommend concomitant atrial reduction or aneurysm resection in symptomatic patients. Conclusions: Giant atrial pathology, though uncommon, carries significant cardiac and extracardiac implications. Management should be individualized, and awareness of atypical manifestations is critical for timely diagnosis and treatment.

Background and Clinical Significance: Cardiac myxomas, though typically benign and asymptomatic, can rarely present with acute cardiovascular compromise. We report a case of a left atrial myxoma presenting as acute pulmonary edema in a patient with prior normal cardiac imaging. Case Presentation: A 55-year-old male, with a history of thrombolyzed myocardial infarction and normal coronary angiography and echocardiography five years earlier, was admitted with acute dyspnea and pulmonary edema. Bedside transthoracic echocardiography (TTE) revealed a left atrial mass causing severe mitral inflow obstruction. Emergency surgical excision was performed, and the mass was submitted for histopathological analysis. Discussion: Histology confirmed cardiac myxoma. The procedure and recovery were uneventful, and follow-up at one month confirmed no recurrence. Conclusions: This case illustrates the potential for cardiac myxoma to manifest suddenly with life-threatening symptoms, even after previously normal investigations. Echocardiography remains pivotal in diagnosing intracardiac masses and guiding timely intervention.

Background/Objectives: Pericardial effusion may occur in patients with established cancer but may also represent the first manifestation of an occult malignancy. This study evaluated the diagnostic contribution of pericardial fluid cytology and pathological assessment according to previous oncological status, with particular emphasis on previously unrecognized malignancy. Methods: We conducted a retrospective observational study of patients hospitalized with pericardial disease between January 2021 and December 2025 at a tertiary cardiovascular center. The final cohort comprised 234 clinical episodes in 209 patients. Clinical, laboratory, imaging, procedural, cytological, and histopathological data were analyzed in relation to previous oncological status and malignant pericardial involvement. Results: Pathological assessment was available in 95/234 episodes (40.6%), with neoplastic involvement identified in 21/95 (22.1%). Neoplastic findings occurred in 13/33 (39.4%) evaluable episodes with known malignancy and 8/62 (12.9%) without a previous cancer diagnosis (odds ratio, 4.39; 95% confidence interval, 1.59–12.11; p = 0.004). Conversely, 20/33 (60.6%) evaluable episodes in patients with known cancer showed no neoplastic involvement. In all eight patients without previously known malignancy, pericardial fluid cytology provided the first pathological evidence of cancer; six (75%) had findings suggestive of a pulmonary origin. All presented with large effusions and hemodynamic compromise. Conclusions: Pericardial pathological assessment provides diagnostic information beyond previous oncological status. It can distinguish malignant from non-neoplastic pericardial involvement in patients with established cancer while also revealing occult malignancy when pericardial disease is its first presentation.