Retroperitoneal metastatic squamous cell carcinoma of the tonsil (with elevated beta human chorionic gonadotrophin): a misdiagnosis as extra-gonadal germ cell tumour

Head and neck cancers usually spread first to the regional lymph nodes but rarely may metastasize to distant sites. Metastasis to distant lymph node groups is a rare event. Furthermore, delayed multiple metastases without local recurrence is relatively uncommon. A case of retroperitoneal metastasis from a squamous cell carcinoma of the tonsil, secreting beta human chorionic gonadotrophin (beta-hCG), is reported. A 58-year-old man had undergone a tonsillectomy and chemo-radiotherapy for squamous cell carcinoma of the left tonsil and 13 months later presented with non-specific abdominal pain. The serum beta-hCG levels were high and an abdominal ultrasound scan revealed hydronephrosis on the left side. A computed tomography scan demonstrated para-aortic retroperitoneal lymphadenopathy. The patient underwent an open lymph node biopsy. The initial pathological analysis was interpreted as extra-gonadal germ cell turnout and the patient received chemotherapy. A subsequent review was consistent with a metastatic squamous cell carcinoma of the tonsil, as immunohistochemical studies showed positive staining for epithelial membrane antigen and cytokeratins 5/6 but a negative reaction to placental alkaline phosphatase. Following this, the chemotherapy regimen was changed; however, a restaging scan demonstrated progression, and the patient died from aspiration pneumonia secondary to alcohol intoxication. To our knowledge, this is the first reported case of retroperitoneal metastasis from a squamous cell carcinoma of the tonsil, secreting beta-hCG and causing hydronephrosis. This case highlights the necessity of using clinical, histological, immunohistological and ultrastructural examination to establish precise diagnosis and to avoid inappropriate treatment.