Endocrine Abstracts

Background: Burned-out tumours (BOT) are rare clinical entities which present with no primary testicular lesion but distant metastases. We report a difficult management of BOT.

Case Presentation: A 22-year-old male presented to ER with acute low back pain, severe vomiting and sweating. In past medical history: bilateral orchidopexy for cryptorchidism. Abdominal CT scan displayed two retroperitoneal masses of 35 and 20 mm. The patient was discharged with suspicion of paraganglioma and he referred to our department 6 months after. In the suspicion of testicular tumor metastasis, a scrotal US was performed during the first visit, which showed multiple calcifications within the left testis. Serum tumoral markers were increased. A new CT scan showed a dimensional doubling of retroperitoneal masses. BOT was therefore hypothesized. Retroperitoneal biopsy confirmed the diagnosis of metastatic embryonal testicular carcinoma. The patient underwent first-line chemotherapy (BEP protocol, 3 cycles). Post-treatment 18F-FDG-PET confirmed hypermetabolic activity in the left para-aortic site lesion and showed an unexpected additional uptake in the right, healthy testis. Tumoral markers were negative and a new testicular US showed no focal lesions on both testicles. RPLMN was therefore performed. A new 18F-FDG PET confirmed a diffuse right testicular uptake. Again, no intratesticular mass was visible at US. Considering the non-concordance of the two diagnostic tests, in the suspicion of a false positive in testicular uptake, due to testicular cellular hyperactivity, we decided to temporarily suppress pituitary-gonadal axis with injectable testosterone undecanoate. After 3 dose every 6-8 weeks, a new 18F-FDG PET showed no areas of pathological uptake.

Conclusions: In this difficult case the suppression of pituitary-gonadal axis avoided unnecessary bilateral orchiectomy in our patient, creating food for thought on whether orchiectomy is actually necessary in these conditions.