Prostate cancer and sarcoma: Challenges of synchronous malignancies

Abstract

Synchronous primary malignancies are a rare finding which can be difficult to diagnose. We present the case of a 57-year-old patient with a high prostate specific antigen who was found to have prostate cancer on subsequent magnetic resonance imaging. A skeletal metastasis was also identified at the time, although no osteoblastic activity or sclerosis was identified on skeletal scintigraphy or computed tomography, respectively. The patient was started on hormonal therapy and follow-up imaging revealed the prostate cancer to have reduced in volume. Despite this, the skeletal metastasis appeared unchanged on magnetic resonance imaging and an F18-choline positron emission tomography study was negative. A computed tomography guided bone biopsy was organized and this demonstrated metastatic leiomyosarcoma. As a result, an F18-fluorodeoxyglucose positron emission tomography study was performed to find the primary lesion which demonstrated a large malignant tumor within the calf. Subsequently, the patient was referred to a tertiary sarcoma unit. This case highlights the challenges involved in diagnosing and managing synchronous malignancies.