A 69 year-old woman, with abdominal pain, showed a large pelvic mass. She had undergone a colpohysterectomy for uterine descensus without ovariectomy three years earlier. Ultrasound showed an ovarian mass with both solid and cystic areas. The patient underwent a bilateral salpingo-oophorectomy.
The right ovary, surgically resected, was greatly enlarged (27 × 12, 5 × 4 cm). Sections showed cystic areas containing soft yellow material and hairs, as well as solid areas with hemorrhage and necrosis. In contrast, the left ovary appeared normal. Formalin-fixed paraffin-embedded tissues were stained with hematoxilin-eosin and Periodic acid-Schiff reagent. Immunohistochemical studies were performed using the streptavidin-biotin peroxidase method. The antibodies used were against cytokeratins (AE1/AE3, CAM 5.2, MNF 116) (Dako, Denmark), EMA, vimentin, alpha smooth muscle actin, estrogen and progesterone receptors, p53, p63 (all from Biogenex-Menarini, Netherland), CD10 and desmin (both from Diapath-Novocastra, Newcastle, United Kingdom). For each antibody, appropriate positive and negative controls were included.
The tumor had features of a carcinosarcoma with cystic areas delimited by squamous epithelium, focally without atypias (Figure ) but with transitional areas from benign through premalignant to "in situ" and infiltrating carcinoma. Hair follicle buds were sometimes present in proximity to the squamous components.
Figure 1 • A: Cystic area delimited by benign squamous epithelium, with transitional area to premalignant. Sarcomatous component is present. • B: Pleomorphic cells in sarcomatous component. • C: Positive staining for CK AE1/AE3 in squamous (more ...)
The sarcomatous component showed compact tissue composed of round cells arranged concentrically around small vessels, spindle, and pleomorphic cells with a high nuclear-cytoplasmic ratio (Figure ). Necrosis and hemorrhage were abundant. Interestingly, islands of SCC were distributed among sarcomatous areas, without a well-demarcated boundary.
The squamous component stained positively for EMA and cytokeratins AE1/AE3 (Figure ) and, MNF 116. In contrast, the stromal component was positive for vimentin, CD10 and, focally, for alpha smooth muscle actin.
Moreover, vimentin, alpha smooth muscle actin and CD10 were positive in atypical basal cells of the squamous epithelium infiltrating both lining cystic areas (Figures ).
Desmin was expressed in fewer than 5% of the stromal cells.
Estrogen receptors were negative. Progesterone receptors were positive in 10% of the sarcomatous cells. P53 and P63 showed positive nuclears staining in about 20% of the tumor cells, in both the sarcomatous and the squamous areas, and in the atypical basal cells of the squamous lining.