title: Interplay of pregnancy, lactation, and hyperthyroidism leading to severe osteoporosis in a young woman.
abstract: OBJECTIVE
  To describe the case of a young woman who had severe osteoporosis due to the compounding effects of pregnancy, lactation, and hyperthyroidism and who had a presumed metastatic lesion in the lumbar spine.
  
  
  METHODS
  We present the clinical, pathologic, radiologic, and laboratory findings and describe the clinical course of our patient.
  
  
  RESULTS
  A 31-year-old Arabic woman was referred to the M. D. Anderson Cancer Center because of a lytic lesion in her lumbar spine, presumed to be metastatic deposits. She had a history of two consecutive pregnancies and intermittently treated hyperthyroidism. Our initial evaluation revealed that the patient had clinical and biochemical thyrotoxicosis, and we treated her with thionamides, corticosteroids, and radioiodine ablation. Radiologic studies disclosed a complex renal cyst that had increased uptake on a bone scan, which was highly suggestive of a primary malignant lesion. Ultimately, however, it proved benign on pathologic analysis after a left nephrectomy. Bone mineral density measurements identified severe osteoporosis (T-scores: lumbar spine, -3.3; right hip, -2.2; and left hip, -2.0), which had led to vertebral collapse and was misinterpreted as malignant metastatic disease. The bone mineral densities improved (+5 to +11% at the various sites) within 4 months after definitive treatment and cure of the hyperthyroidism.
  
  
  CONCLUSIONS
  The effect of pregnancies and prolonged lactation, in the milieu of other risk factors for bone depletion such as hyperthyroidism, may cause severe osteoporosis in a young patient. The resulting osteoporosis may manifest as a lesion suggestive of malignant metastatic involvement.
authors.affiliation: Section of Endocrine Neoplasia and Hormonal Disorders, Department of Internal Medicine Specialties, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA.
authors.forename: R V
authors.initials: RV
authors.lastname: Sekhar
authors.forename: R
authors.initials: R
authors.lastname: Vassilopoulou-Sellin
mesh_terms: D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000328:Adult; D015519:Bone Density; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D006980:Hyperthyroidism / Q000150:complications* / Q000175:diagnosis / Q000628:therapy; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D052177:Kidney Diseases, Cystic / Q000150:complications / Q000175:diagnosis; D007774:Lactation; D008159:Lumbar Vertebrae; D008713:Methimazole / Q000627:therapeutic use; D010024:Osteoporosis / Q000175:diagnosis / Q000209:etiology*; D011247:Pregnancy; D011441:Propylthiouracil / Q000627:therapeutic use; D016103:Spinal Fractures / Q000175:diagnosis / Q000209:etiology*
chemical_list: D000305:Adrenal Cortex Hormones; D007457:Iodine Radioisotopes; D008713:Methimazole; D011441:Propylthiouracil