Distinguishing between lymphangioleiomyomatosis and carcinomatous peritonitis in a patient with ovarian cancer.

Case Report A 48-year-old woman with no notable medical or family history visited our hospital with a complaint of abdominal bloating. An ultrasonography scan showed severe accumulation of ascites in her pelvis, and magnetic resonance imaging revealed a solid mass measuring 15 cm in diameter. The mass was assumed to be ovarian cancer (OC) accompanied by carcinomatous peritonitis. We performed abdominal total hysterectomy, bilateral salpingooophorectomy, pelvic lymphadenectomy, para-aortic lymphadenectomy, and omentectomy as staging laparotomy and debulking surgery for OC. The left ovary measured 15 cm in diameter, and the tumor was present on its surface. The volume of ascites was 8,250 mL, although neither peritoneal metastasis nor carcinomatous peritonitis was noted. A careful examination of the peritoneal cytology, involving the centrifuged pellet from almost all of the ascites, failed to detect any malignant cells. Pathologic examination confirmed that the pelvic mass was OC (endometrioid adenocarcinoma, G1), and the International Federation of Gynecology and Obstetrics stage was Ic(a). No metastasis was detected in the omentum, lymph nodes, and lymph duct or vessels. However, pathologic examination incidentally revealed lymphangioleiomyomatosis (LAM) in the lymph nodes and lymphatic vessels (Fig 1). Hematoxylin and eosin staining revealed oval to short spindle-shaped smooth muscle-like cells (LAM cells) aggregating and proliferating in a nodular pattern within lymph ducts and vessels (Fig 1A). The LAM cells were positive for smooth muscle actin, HMB-45 (Fig 1B), estrogen receptor, and progesterone receptor. High-resolution computed tomography of the chest revealed six small (2 to 5 mm), thin-walled cysts in the upper lobes of both lungs before the operation (Fig 2A, arrows). Pathologic examination of the lymph nodes and lymphatic vessels indicated that the pulmonary cysts were LAM lesions. In addition, a sarcoidlike reaction, which contained noncaseating epithelioid cells, was occasionally detected in regional lymph nodes (Fig 1C). This case did not fulfill the criteria for systemic sarcoidosis, and there was no evidence of metastatic ovarian adenocarcinoma. Cell count, biochemical analysis, culture, polymerase chain reaction for Mycobacterium tuberculosis, and cytologic examination of ascitic fluid were performed for differential diagnosis of the massive ascites. Abdominal ultrasonography and computed tomography were also performed to identify the cause of ascites or findings suggestive of portal hypertension. Bacterial peritonitis, tuberculous peritonitis, and portal hypertension were not considered likely causes. Abdominocentesis was frequently performed postoperatively to prevent abdominal distention and to facilitate peritoneal cytology. No malignant cells were detected after any of these procedures. This patient was a suitable candidate for adjuvant chemotherapy. Paclitaxel (180 mg/m) and carboplatin (area under the curve, 6) were administered once every 3 weeks. A severe adverse event (grade 3 neuropathy as per the National Cancer Institute Common Terminology Criteria for Adverse Events, version 3.0) occurred after three cycles had been administered, and chemotherapy was therefore discontinued. In this patient, ascites had markedly diminished at 3 months and disappeared at 6 months after the operation. Moreover, lung cysts and pulmonary function did not subsequently worsen. No remarkable changes in either the size or number of cysts were observed 5 years later (Fig 2B, arrows). Figure 3 shows the postoperative changes in pulmonary function expressed as a percentage of predicted forced vital capacity (FVC) and forced expiratory volume in the first second (FEV1). These pulmonary function tests subsequently improved. The patient remained well 5 years after the operation with neither recurrence nor LAM symptoms.