Primary cardiac leiomyosarcoma is not common but is lethal. Prompt
surgery is mandatory for identifying the etiology while a comprehensive
examination of pathology is crucial especially in the condition of two
tumors with different etiologies. A 52-year-old man with medical history
of systemic hypertension presented with chest discomfort and dyspnea.
Echocardiography revealed the dilated right ventricle with a mass at
right ventricular outlet tract (RVOT) (Figure 1A). It caused critical
obstruction and resulted in severely pulmonary hypertension (estimated
pulmonary systolic pressure up to 108mmHg). Cardiac magnetic resonance
imaging confirmed a heterogeneous mass at RVOT with a high-intensity in
T2 weighted image but failed to differentiate whether it is myxoma,
metastasis or primary cardiac malignancy (Figure 1B). Given the
exacerbating dyspnea, he received a prompt surgery which identified two
tumors. One in the size of 9*4 cm originated from the RV dome extending
to RVOT and pulmonary artery. The other smaller one (5*3 cm) mainly
located within the RV (Figure 1C). The surgeon excised the smaller one
for the frozen section while the immediate pathology reported that it
was a benign lesion. Both tumors were removed. Surprisingly, post the
operation the final pathology revealed that despite one tumor of benign
degenerative tissues, the other of rare cardiac leiomyosarcoma at T1
stage. Immunohistochemical staining showed positive for smooth muscle
actin and h-Caldesmon which is specific for leiomyosarcoma (Figure 1D).
The patient subsequently received chemotherapies of Doxorubicin 75mg/m2
for 4 cycles.