Destructive granuloma derived from a liver cyst: a case report

Abstract

We herein report the case of an idiopathic liver cystic mass which aggressively infiltrated the thoraco-abdominal wall. A 74-year-old woman who had a huge cystic lesion in her right hepatic lobe was transferred to our hospital for further examinations. Imaging studies revealed a simple liver cyst, and the cytological findings of intracystic fluid were negative. She was followed up periodically by computed tomography (CT) scans. Seven years later, she complained of a prominence and dull pain in her right thoraco-abdominal region. CT revealed an enlargement of the cystic lesion and infiltration into the intercostal subcutaneous tissue. We suspected the development of a malignancy inside the liver cyst such as cystadenocarcinoma, and she therefore underwent surgery. A tumor extirpation was performed, including the chest wall, from the 7th to the 10th rib, as well as a right hepatic lobectomy. Pathologically, the lesion consisted of severe inflammatory change with epithelioid cell granuloma and bone destruction without any malignant neoplasm. No specific pathogens were evident based on further histological and molecular examinations. Therefore the lesion was diagnosed to be a destructive granuloma associated with a long-standing hepatic cyst. Since undergoing surgery, the patient has been doing well without any signs of recurrence.

Figure 1

Computed tomography revealed a huge multilocular cyst measuring 10 cm in the right lobe of the liver on September 11th, 1997 (A). A similar cyst with a calcified lesion was found in the right lobe of the liver on May 15th, 2003 (B).

Figure 2

An axial (A) and coronal (B) view of magnetic resonance imaging (MRI) showed a multilocular cyst with a thick wall with a solid component extending into the subcutaneous tissue. MR cholangio-pancreatography showed no dilatation in the biliary system, and most likely no communication with the liver cyst (C). The skin showed red swelling by the subcutaneous extension of the hepatic cyst (D).

Figure 3

An en bloc resection resulted in a huge defect (A, yellow dotted circle). The defect of the diaphragm was covered with the great omentum, and the thoraco abdominal wall defect was reconstructed by a musculo-cutaneous flap including the anterior sheath and the left rectus abdominis muscle which both receive the blood supply comes from the superior abdominal artery (B).

Figure 4

Macroscopically, the cystic mass directly invaded the intercostal space through the diaphragm (A. Resected crude specimen, black triangle; skin, black arrow head; ribs, white triangle; cystic tumor; B. Cut surface of the specimen, black arrow head; subcutaneous invasion, white triangle; cystic tumor). Microscopically, the bone was destroyed by an invasion of granuloma tissue (C). The granuloma was composed of epithelioid cells with necrotic areas (D).