Cardiac paraganglioma: implications and impacts of a rare disease-a case report †

Abstract

Background: Tumour-producing catecholamines arise in the adrenal medulla (pheochromocytomas), as well as in extra-adrenal chromaffin cells (paragangliomas). The origin can be from any location; however, it is very rare in the heart.

Case summary: A 43-year-old woman with a history of arterial hypertension presented with dyspnoea on moderate exertion, New York Class Association (NYHA) functional classes III and IV, and oedema in the lower extremities. Medical and laboratory evaluation revealed an NT-proBNP of 6046 pg/mL, a left ventricular ejection fraction (LVEF) of 15%, longitudinal strain of -7%, and a mass located on the inner surface of the left atrioventricular groove. Surgical intervention was performed, and the tumour was resected. Pathological report showed an extra-adrenal paraganglioma without neoplastic involvement in the margins of the vena cava. After surgery, the patient showed clinical improvement with NYHA functional class I, LVEF of 56%, and longitudinal strain of -20% on transthoracic echocardiography 4 months after treatment.

Discussion: Paragangliomas are tumours that are rarely found in the heart, and their diagnosis is difficult. However, early detection and treatment can improve the quality of life of affected patients.

Keywords: Cardiac tumour; Case report; Catecholamines; Dilated cardiomyopathy; Heart failure; Paraganglioma.

Figure 1

Electrocardiogram. Heart rate 145 b.p.m. QRS duration 90 ms. RP>PR. Atrial tachycardia.

Figure 2

Transoesophageal echocardiogram. The arrow indicates the 50 × 40 mm image in the right atrium.

Figure 3

Cardiac magnetic resonance imaging. (A) Two-chamber long-axis view. T₁ contrast enhanced with early post-gadolinium enhancement (arrow). (B) Short-axis view. T₁ contrast enhanced, a late enhancement over the atrioventricular groove, with areas of intense enhancement in the central portion of the lesion (arrow). (C) Two-chamber long-axis view. T₁ contrast enhanced, a late enhancement over the atrioventricular groove, with areas of intense enhancement in the central portion of the lesion (arrow). (D) Native (simple) T₁ map in the mid-ventricular short-axis view, showing mild alterations.

Figure 4

Axial computed tomography of the heart. (A) Two-chamber long-axis view in venous phase. The coronary sinus (arrow) is compressed cephalically by the mass located in the atrioventricular groove, below the inferior wall of the left atrium. Progressive enhancement with intratumoural vessels indicative of its high vascularity. (B) Maximum intensity projection of the contrast. Intratumoural vascularization from the right coronary artery (arrow). (C and D) Maximum intensity projection of the contrast, where the main nutrient vessel originating from the circumflex artery is delineated (arrows), along with another vessel originating from the posterolateral branch of the right coronary artery. There is a prominent arterial vessel located within the lesion (D, arrows).

Figure 5

Histology (A) and immunohistochemistry (B and C). (A) Neoplastic lesion composed of intermediate-sized oval or ovoid cells with nuclei showing fine granular chromatin, exhibiting mild cytological atypia, and possessing pink cytoplasm. These cells form an ‘organoid’ pattern within thin fibrous septa (zellballen pattern). Dilated small blood vessels are observed. No areas of necrosis are present. (B and C) The neoplastic cells show positivity for CD56, synaptophysin, chromogranin, and S-100, while being negative for CKAE1-AE3, PAX-8, and PAGF. The vascular marker CD31 highlights the presence of small capillary vessels. The proliferation index KI-67 is <2%. The histological and immunophenotypic profile is consistent with a non-malignant neuroendocrine neoplasia, resembling a paraganglioma.