Benign Metastatic Leiomyoma: Unusual Heart Location

Case Report

Austin J Pathol Lab Med. 2021; 8(1): 1031..

Benign Metastatic Leiomyoma: Unusual Heart Location

Elaouni S1,2,3*, Jebli S1,2, Sassi S1,2, Bernoussi Z1,2, Jahid A1,2, Zouidia F1,2 and Znati K1,2

¹1Department of Pathology, Ibn Sina Hospital, University in Rabat, Morocco

²University Mohamed V Rabat, Faculty of Medicine and Pharmacy, Morocco

³Department of Pathology, Ibn Sina Hospital, University Mohamed V Rabat, Morocco

*Corresponding author: Elaouni S, Department of Pathology, Ibn Sina Hospital, University Mohamed V Rabat, Morocco

Received: April 06, 2021; Accepted: April 26, 2021; Published: May 03, 2021


Cardiac smooth muscle tumors are rare; three different clinical settings for these tumors have been reported, including benign metastasizing leiomyoma from the uterus, primary cardiac leiomyoma and leiomyosarcoma, and intravenous cardiac extension of pelvic leiomyoma, which is the most common. We present a case of a 56-year-old woman with a benign metastasizing leiomyoma to the heart without associated pulmonary localization 15 years after endoscopic vaginal myomectomy of polymyomatous uterus. Immunohistochemical stains for H-Caldesmon, Desmin, and estrogen, progesterone receptors were positive, indicating a smooth muscle tumor of uterine origin. To our knowledge, this is only the fifth reported case of benign metastasizing leiomyoma to the heart with histological proof and the first case of earlier onset cardiac metastasis without pulmonary metastasis localization. It illustrates that benign metastasizing leiomyoma should be included in the differential diagnosis of cardiac tumors in patients with a history of surgery uterine leiomyoma perfectly benign.

Keywords: Heart; Benign metastasizing leiomyoma; Uterine surgery


Primary cardiac tumors are rare, and most cardiac tumors are secondary to metastatic disease [1]. Smooth muscle tumors of the heart are extremely rare. Three different clinical settings for cardiac smooth muscle tumors have been reported: intravenous cardiac extension of pelvic leiomyomas [2] benign metastasizing leiomyomas from the uterus [1,3,4] and primary cardiac leiomyomas and leiomyosarcomas [5]. Here we report a rare entity of metastasizing leiomyoma to the heart with review of the literature.

Case Presentation

A 56-year-old woman presented at a provincial hospital with dyspnea and shortness of breath. On imaging, she was found to have a right atrial mass initially thought to be a thrombus. She was subsequently referred to university hospital center (CHU Ibn Sina, Rabat) for further workup and management. Cardiac Magnetic Resonance Imaging (MRI) showed a monolobed, pedunculated, mobile, well-circumscribed mass attached to the intra-atrial septum. The resected tumor was sent to us for histological confirmation. Pulmonary radiological exploration did not find a suspicious mass.

Additional history was pursued as part of the pathologic workup, and it was determined that the patient had undergone a uterine surgery endoscopic vaginal of polymyomatous uterine 15 years earlier at the age of 41 years. The uterine mass operated on was a leiomyoma with no malignant features; no necrosis, atypia, or increased mitotic activity was seen. The patient lost to follow up until she consulted for her cardiac symptomatology resulting in a discovery of mass in the right atrium.

The 8cm x 5cm x 3cm resected cardiac tumor was solid, graywhite, and homogeneous fasciculate with no hemorrhage or necrosis (Figure 1). Microscopically, the tumor was composed of bundles of bland spindle cells with “cigar-shaped nuclei”, no nuclear atypia or necrosis, and only rare mitoses (less than 1/10 high-power fields) (Figure 2). Immunohistochemically, the spindle tumor cells expressed H-Caldesmon (Figure 3) and Desmin (Figure 4) and were negative for S100 (Figure 5) Protein. MIB-1 immunohistochemical staining showed low proliferative activity, with less than 1% MIB- 1-positive cells. The tumor cells were strongly positive for Estrogen Receptors (ER) and for Progesterone Receptors (PR) (Figure 6 and 7), supportive of uterine origin. The patient is alive and well 16 months after resection of the cardiac tumor, with no evidence of further metastasis.