Proximal-Type Epithelioid Sarcoma With Elevated Serum CA 125: Report of a Case With CA 125 Immunoreactivity

Archives of Pathology & Laboratory Medicine, Jun 2006 by Lee, Hyang-Im, Kang, Kil Hyun, Cho, Young Mee, Lee, Oak-Jun, Ro, Jae Yoon

Proximal-type epithelioid sarcoma is a recently described rare soft tissue neoplasm. It is commonly found in the pelvic, perineal, and genital areas in middle-aged or older adults, as compared with the classic type of epithelioid sarcoma, which arises in the distal portion of the extremities in adolescents and young adults. Proximal-type epithelioid sarcoma has a more aggressive clinical behavior than the classic type of epithelioid sarcoma. Proximal-type epithelioid sarcoma is histologically characterized by a diffuse proliferation of epithelioid cells with prominent rhabdoid feature. Recently, a few cases have been reported of epithelioid sarcoma with elevated serum CA 125 level and CA 125 immunoreactivity in neoplastic cells. These cases raise the possibility that serum CA 125 and CA 125 immunoreactivity could be a useful tumor marker for diagnosing and monitoring epithelioid sarcoma. We describe a case of proximal-type epithelioid sarcoma with elevated serum CA 125 level (up to 3395 U/mL [reference range,

(Arch Pathol Lab Med. 2006; 130:871-874)

Proximal-type epithelioid sarcoma, which was first described by Guillou et al,1 is a rare, soft tissue, malignant neoplasm that predominantly occurs in the pelvis, perineum, and genital area in middle-aged or older adults. Histologically, proximal-type epithelioid sarcoma is characterized by a predominantly large cell, epithelioid cytomorphology, marked cytologie atypia with vesicular nuclei and prominent nucleoli, and frequent occurrence of a rhabdoid feature.1 Rare cases show hybrid histologic features of the classic and proximal subtypes. Proximal-type epithelioid sarcoma has a more aggressive clinical behavior than does the classic type of epithelioid sarcoma and is associated with early development of metastasis and a higher incidence of tumor-related deaths.

The histogenetic origin of epithelioid sarcoma is unknown. Immunohistochemical studies have been performed by previous investigators to characterize this tumor.2 However, a specific tumor marker for the diagnosis of epithelioid sarcoma has not yet been established. According to the literature, there have been no reports of serum CA 125 elevation in proximal-type epithelioid sarcoma; there have been 2 cases with elevated serum CA 125 in the classic epithelioid sarcoma, reported by Kato et al.3 Although the reason for the elevation of CA 125 in epithelioid sarcoma was unclear, these authors suggested that CA 125 could be a useful tumor marker for diagnosing epithelioid sarcoma and monitoring its clinical course because the initial serum CA 125 values of both patients were high and changed with the progression of the tumor growth, and an immunohistochemical study demonstrated that the tumor cells in both cases expressed CA 125. Kato et al4 did a subsequent study on 11 cases of epithelioid sarcoma, which included the 2 previously reported cases3 and another patient showing an elevated CA 125 serum level; 10 of their 11 cases showed strong immunoreactivity for CA 125 in the tumor cells. Control cases, including patients with other mesenchymal tumors and with granulomas, had negative immunoreactivity for CA 125. These studies clearly demonstrate the specificity and positively of CA 125 in epithelioid sarcoma and indicate that CA 125 may be a useful tumor marker for diagnosing epithelioid sarcoma.

Recently, we experienced a case of proximal-type epithelioid sarcoma with elevated serum CA 125 level in a 12-year-old girl. She presented with a 12-cm pelvic mass. In this report, we describe this case and we discuss the possible utility of serum CA 125 elevation and CA 125 immunoreactivily for the diagnosis and follow-up of patients with epithelioid sarcoma.

REPORT OF A CASE

A 12-year-old girl presented to our hospital in September 2003 with an abdominal mass. Physical examination disclosed a large mass in the pelvic cavity. Blood analyses revealed CA 125, 3395 U/mL (reference range,

It was discovered during surgery that the pelvic cavity was almost entirely replaced by a single, large, multilobulated solid mass. The tumor was diffusely adherent to both ovaries, the appendix, uterus, rectum, and sigmoid colon. Both ovaries were of normal size and shape except for several small nodules; the largest of these nodules, found on the left ovarian surface, measured less than 0.5 cm in greatest dimension. The right ovary, both fallopian tubes, uterus, rectum, and sigmoid colon were not grossly involved by the tumor. Therefore, we performed total resection of the pelvic mass, wedge biopsy of the left ovarian nodules, and appendectomy.

The histologic diagnosis of the pelvic mass was proximal-type epithelioid sarcoma, and the pathologic finding of the nodules on the left ovarian surface was similar to that of the pelvic mass. The tumor was adhered to the ovarian surface without invading the ovarian parenchyma. The appendix was free of tumor. After the clebulking surgery, the serum CA 125 level was decreased to 452 U/mL. The patient received one cycle of chemotherapy, including ifosfamide, carboplatin, and etoposide, but died of the disease 2 months after diagnosis.