YO8 - Choriocarcinoma presenting with thyrotoxicosis

Date 18 December 2016
Event ESMO Asia 2016 Congress
Session Poster lunch
Topics Gynaecological Malignancies
Presenter Aisha Al Salami
Authors A. Al Salami, O. Al Hammadi, R. Singarachari, G. Sathyarathnam
  • Medical Oncology, Sheikh Khalifa Medical City-Abu Dhabi General Hosp Abu Dhabi, 51900 - Abu Dhabi/AE

Abstract

Case Summary

We present a 40 year old lady with metastatic choriocarcinoma presenting with clinical hyperthyroidism associated with eleveated HCG

This previously healthy 40 year old lady presented to the Casualty with 8 months history of weight loss and 2 months history of vomiting, shortness of breath, bleeding from the vagina.

She was premenopausal. Her last child birth was13 years ago.

She was tachypnoeic, tachycardic,had exophthalmos and fine tremors of both hands. Her HCG was raised at 729,013 IU/L. Her TSH was low at 0.005 milliIU/L, free T4 was raised at more than 100pmol/L and free T3 was raised at 29.6 pmol/L in keeping with hyperthyroidism. CT Chest and upper abdomen showed multiple lung nodules scattered throughout both lung fields. No liver metastases. Ultrasound pelvis showed bulky uterus multiple sonolucent areas suggestive of neovascularization.

A diagnosis of choriocarcinoma with lung metastases and thyrotoxicosis due to the thyrotropic effect on HCG was made. Carbimazole and Propranolol were started for the thyrotoxicosis. Chemotherapy was commenced with EMA/CO - alternating weeks of Etoposide, Methotrexate, Actinomycin D and Cyclophosphamide and Vincristine.At cycle 2 day 8 , three weeks since starting chemotherapy, the HCG fell from the previous 729,013 to 1,933. The TSH was 0.397 and clinically and biochemically she was euthyroid. Carbimazole was stopped.

She finished her course of chemotherapy with disappearance of the lung metastases and has now been referred for hysterectomy.

Association between raised HCG and suppressed TSH, though uncommon has been well documented in gestational neoplasias and other germ cell tumours secreting HCG. Often in these patients T3 and T4 are normal and patients are asymptomatic. With the fall in HCG the thyroid functions normalize and patients rarely require any treatment for the transient abnormal thyroid biochemistry.There have been a small number of case reports of gestational trophoblastic disease presenting in association with symptomatic hyperthyroidism.The fall in HCG correlates with improvement in thyroid function.

The effect on the thyroid is thought to occur due to molecular mimicry between HCG subunits and TSH. Extremely high levels of HCG are usually required for an effect on thyroid function to be seen.