A thecoma, also known as a theca cell tumor, is classified as an ovarian sex cord stromal tumor. This type of tumor is relatively rare. Thecomas compromise only around 1 percent of all ovarian tumors.
The ovaries produce theca cells, endocrine cells that control the production of androgen hormones. Pure thecoma tumors are composed of theca cells. The tumors are usually a yellowish or orange color with a well-defined shape and a rigid, inflexible consistency. They grow to between 0.25 inch and 0.31 inch (between 7 cm and 8 cm) on average, but their size varies widely depending on the patient. Theca cell tumors often contain droplets of fat and a jelly-like liquid called cytoplasm.
Typical thecomas usually affect women around menopause, and women between the ages of 50 and 60 years old are in the highest risk category. More than 90 percent of all thecomas are unilateral, or only affect one side, but they occasionally form on both ovaries. They are benign in most cases. Once in a while a thecoma tumor will turn out to be malignant. Malignant tumors usually contain granulosas, which are a different type of ovarian cell, as well as theca cells.
Thecomas usually produce estrogen. Some women who develop thecomas experience symptoms such as irregular menstruation or post-menopausal spotting or bleeding because of excess estrogen production. Other thecoma tumors produce androgens, which are male hormones that are produced in the female adrenal glands and the ovaries. Younger women — those under 30 — are susceptible to luteinizing thecomas, which are a type of tumor that contains steroid cells. A rare type of thecoma, called a Sertoli-Leydig tumor, produces testosterone, so women with this type of thecoma may develop masculine characteristics such as a deepening voice and excess facial hair.
Treatment options include complete hysterectomy, which removes the uterus and ovaries; surgical oophorectomy, or removal of the ovary; and salpingo-oophorectomy, or removal of the fallopian tube and ovary. These surgeries are generally curative, because they remove the hormone-producing tumor. Younger women who want to become pregnant at some point can opt for a wedge resection surgery, which only removes part of the ovarian tissue to limit the amount of hormones that are being produced. Physicians often recommend more radical surgeries for women who have granulosa cells mixed in with thecoma tumors, because this type of tumor occasionally becomes malignant. Many of the symptoms of excessive hormones clear up within several months after surgery.