Incidental dedifferentiated mediastinal liposarcoma on F-18-fluciclovine PET/CT

• Published in: Clinical imaging 2020-01, Vol.59 (1), p.21-24
• Main Authors: Boatright, Christine, Walker, Christopher M., Donald, Joseph, Cui, Wei, Nagji, Alykhan S.
• Format: Article
• Language: English
• Subjects: Aged; Cancer surgery; Cancer therapies; Carboxylic Acids; Consultation; Cyclobutanes; Fat-containing mass; Fluciclovine; Fluorine isotopes; Humans; Liposarcoma; Liposarcoma - diagnostic imaging; Liposarcoma - pathology; Lymph nodes; Lymph Nodes - pathology; Magnetic resonance imaging; Male; Malignancy; Mediastinal liposarcoma; Mediastinum - pathology; Medical prognosis; Metabolism; Metastases; Metastasis; Mortality; Neoplasia; Neoplasm Recurrence, Local - diagnostic imaging; Neoplasm Recurrence, Local - pathology; Neoplasms; PET/CT; Positron Emission Tomography Computed Tomography - methods; Prostate cancer; Prostatectomy; Prostatic Neoplasms - diagnostic imaging; Prostatic Neoplasms - pathology; Prostatic Neoplasms - surgery; Radioactive tracers; Radioisotopes; Radiology; Radiopharmaceuticals; Soft tissues; Tumors
• ISSN: 0899-7071; 1873-4499
• DOI: 10.1016/j.clinimag.2019.08.004

Fat-containing mediastinal masses, particularly mediastinal liposarcomas, are rare neoplasms that can grow to large sizes before becoming symptomatic and may be incidentally found on radiology examinations. In this case report, a 67-year-old male with a history of prostate cancer status post prostatectomy presented for an F-18-fluciclovine PET/CT for a rising, clinically detectable PSA and indeterminate pelvic lymph nodes seen on multiparametric MRI of the prostate. No local tumor recurrence or metastatic disease from prostate cancer was identified, but the PET/CT demonstrated a mixed soft tissue and fat density prevascular (anterior) mediastinal mass with low-level radiotracer uptake. Following surgical consultation and resection, the final pathology revealed a dedifferentiated mediastinal liposarcoma. The case presented describes the appearance of an uncommon fat-containing mediastinal mass and describes several other fat-containing mediastinal masses that are important for radiologists to recognize in order to formulate accurate differential diagnoses and ensure appropriate further management for patients. Additionally, this case demonstrates that the radiotracer F-18-fluciclovine is not specific for prostate cancer, and its uptake can be seen with other entities such as in this case of sarcomatous malignancy. •Fat-containing mediastinal masses are often incidentally found, growing to large size before becoming symptomatic.•Liposarcomas within the mediastinum are a rare though important consideration for a fat-containing mediastinal mass.•This case describes an incidentally found mediastinal mass found to be a liposarcoma on pathologic examination.