Lesson of the Month: Are we Missing the Mark(Er)?
1. Abstract
Cancers of Unknown Primary (CUP) defines a condition in which a patient has metastatic malignancy with an unidentified primary tumour despite comprehensive investigations. CUPs have an incidence of 3-5% and have a devastating clinical outcome, amounting to the fourth commonest cause of cancer death. We explored four cases of metastatic germ cell tumours originally labelled as CUPs, but their primaries were eventually identified via the use of serum tumour markers and/or acute oncology team review. Failure to perform tests for serum tumour markers early resulted in unacceptable delays in their diagnosis and management. Two of the four patients were also initially misdiagnosed with Lymphoma. These cases highlighted the variability in the initial diagnostic workup of patients with CUP. It also stressed the importance of avoiding lymphoma ‘tunnel vision’ and considering early liaison with acute oncology when faced with diagnostic uncertainty of cancer patients.