Primary Myxoid Leiomyoma of the Liver
A 60-year-old woman complained of upper abdominal fullness. She was taking hypertension and diabetes medications and had undergone a thyroid lobectomy for thyroid papillary carcinoma 4 years earlier. She was discovered to have a low-echogenic mass in the right lobe of the liver on an ultrasound scan. Computed tomography of the abdomen revealed an 8-cm enhancing mass in segment 7 and 8 of the liver (). Liver function tests were unremarkable. Blood tumor markers, including carcinoembryonic antigen, α-fetoprotein, and carbohydrate antigen 19-9 were within normal ranges. The patient was not a hepatitis B carrier and her human immunodeficiency virus serology was nonreactive.\nResults from a further magnetic resonance study suggested metastatic carcinoma from the thyroid. The gastrointestinal and gynecologic tracts were examined and no other lesions were detected. The patient underwent a right hepatectomy to remove the tumor. Grossly, there was an 8×5×4.5 cm, well-demarcated, unencapsulated and soft mass in the liver. The cut surface was yellow-to-tan, myxoid, and rubbery (). Histologically, the tumor was uniformly hypocellular and consisted of scattered, oval-to-spindle tumor cells and variable sized vessels. The stroma was myxoid and edematous (). The spindled tumor cells had slightly eosinophilic cytoplasm. The nuclei of the spindle cells were cigar-shaped, blunt-ended, and showed vesicular chromatin. The nucleoli were inconspicuous. No cellular atypia or mitosis was observed (). Inflammatory cells, especially mast cell and lymphocytes, were easily found.\nImmunohistochemically, the spindle cells stained positively for smooth muscle actin (SMA) () and desmin, but were negative for anaplastic lymphoma kinase (ALK), S-100 protein, human melanoma black 45 (HMB45), c-kit, CD21, CD31, and CD34. Only a few tumor cells were labeled with ki-67. Estrogen receptor and progesterone receptor studies demonstrated negative staining. Thus, the histomorphological and immunophenotype findings were consistent with myxoid leiomyoma of the liver. The patient's postoperative course was uneventful and she has had no sign of recurrence to date.