Metastatic prostate cancer on the thyroid cartilage: unusual symptoms of prostatic adenocarcinoma. Case report.

OBJECTIVE: To review the unusual localizations of metastasic prostate cancer with the contribution of a clinical case of prostatic adenocarcinoma metastasis in the thyroid cartilage.

METHODS: 49-year-old-male admitted with history of 48 hour hematuria associated with lumbar pain radiating to the lower extremities and cervical tumour for 3 months.

RESULTS: CT scan of the thorax, abdomen and pelvis was performed showing an insufflating lesion on the left thyroid cartilage lamina suggesting chondrosarcoma, a 4 cm tumour on the posterior side of the bladder, and metastases on L4-S1 vertebral bodies and left iliac bone. Cystoscopy revealed an image on the posterior vesical wall suggesting prostatic infiltration by a tumoral process without evidence of urothelial tumors. PSA was 617 ng/ml. Digital rectal examination: Prostate with augmented consistency. Due to these results an ultrasound-guided transrectal prostatic biopsy was performed with the pathological result of Gleason 8 prostatic adenocarcinoma involving boths lobes. Complete androgen blockade with Bicalutamide and Goserelin was started with good response lowering the PSA level down to 29 ng/ml. Regarding the cervical mass suggestive of thyroid chondrosarcoma a left vertical partial laryngectomy was performed with replacement of the thyroid cartilage by septal cartilage. Pathological study of the piece revealed the presence of prostatic adenocarcinoma.

CONCLUSION: Metastatic prostate cancer in the thyroid cartilage is exceptional, there being only five cases described in the literature. This fact, linked to the scant frequency of tumours lying in this cartilage and diagnosis by means of radiological suspicion, makes it very difficult to include metastatic prostate cancer in the routine differential diagnosis of cervical masses.