A case of gonadal dysgenesis, breast development, Graves' disease, and low bone mass.

OBJECTIVE

To describe a case of XY gonadal dysgenesis with Tanner stage 4 breast development in the absence of a hormone-producing gonadal neoplasm and with Graves' disease and low bone mass.

METHODS

The clinical features, laboratory results, and cytogenetic findings in the patient are presented, and the potential mechanisms of breast development are discussed. A MEDLINE search was performed, and related articles in the English-language literature published between 1955 and 2001 were reviewed.

RESULTS

A 23-year-old African American woman was referred to the University of Louisville Hospital for evaluation of hyperthyroidism. About 4 months before this referral, hyperthyroidism was diagnosed, and treatment with methimazole was initiated. She continued to have thyrotoxicosis. Additionally, systemic review disclosed a history of primary amenorrhea. Physical examination revealed a tall phenotypic female patient with Tanner stage 4 breast development. Pelvic examination showed normal findings except for sparse pubic hair. Laboratory evaluation confirmed the diagnosis of Graves' disease as well as primary gonadal failure. Pelvic ultrasonography revealed a small uterus and bilateral adnexal masses (0.9 by 0.6 cm). On chromosomal analysis, a 46,XY karyotype was found. Further analysis of Y-DNA by polymerase chain reaction confirmed the presence of an intact Y chromosome, and no microdeletions were identified. Dual-energy x-ray absorptiometry demonstrated a Z-score of -4.7 and -4.2 at the lumbar spine and right hip, respectively. Graves' disease was successfully treated with (131)I. Laparoscopy was performed to resect streak gonads. On histologic examination, no typical ovarian, testicular, or neoplastic tissue was identified. The breast development in this patient remains unexplained.

CONCLUSION

To the best of our knowledge, this is the first case report of a tall XY female patient with breast development in the absence of a hormone-producing gonadal neoplasm and without clearly identifiable gonads. Breast development was most likely related to estrogens, possibly produced by either streak gonads at the time of puberty or peripheral conversion of androgens, or to increased sensitivity of breast tissue to estrogens. Graves' disease is likely coincidental and could contribute to bone loss in such subjects.