Published online 2014 Mar 17. doi: 10.1259/bjr.20130719
PMCID: PMC4097810
Imaging features of primary and metastatic alveolar soft part sarcoma: single institute experience in 25 patients
S Sood, MD,1 A D Baheti, MD,1,,2 A B Shinagare, MD,1,,2 J P Jagannathan, MD,1,,2 J L Hornick, MD, PhD,3 N H Ramaiya, MD,1,,2 and S H Tirumani, MDcorresponding author1,,2
To describe imaging features of primary and metastatic alveolar soft part sarcoma (ASPS).
Methods:
In this institutional review board-approved and Health Insurance Portability and Accountability Act-compliant retrospective study, 25 patients (14 males; mean age, 25 years; range, 18–40 years) with pathologically proven ASPS seen at our institute between 1995 and 2013 were included. Imaging of primary tumours in 5 patients and follow-up imaging in 25 patients were reviewed by 2 radiologists in consensus. Clinical information was obtained from electronic medical records.
Results:
The most common sites for the primary tumour were extremities (17/25, 68%) and torso (6/25, 24%). Primary tumours (n = 5) were well circumscribed, compared with skeletal muscle, were isodense on CT, hyperintense on T1 and T2 weighted images with intense post-contrast enhancement, prominent feeders on CT and flow voids on MRI. Metastases developed in 23/25 (92%) patients, 18 at presentation. The most common sites of metastases were the lungs (100%), lymph nodes (74%), bones (57%) and brain (43%). Visceral and nodal metastases were hypervascular. At the time of reporting the results, 15 patients have died, 6 are alive and 4 were lost to follow-up. Median survival was 74 months for those without brain metastases (n = 8) and 60 months for those with brain metastases (n = 7). Median survival was shorter for patients with metastases at presentation.
Conclusion:
ASPS most commonly involves the lower extremities of young adults, is hypervascular on imaging, often metastasizes at presentation, frequently to lung, nodes, bones and brain, and has an indolent course despite metastases. Brain metastases and high tumour burden (number of metastatic sites) at presentation decreased survival in our study.
Advances in knowledge:
ASPS has an unusual pattern of metastases to the brain and nodes in addition to lung and bones. It has an indolent course despite metastases.
Advances in knowledge
"In spite of the advances in the understanding of its pathogenesis, the origin of ASPS remains obscure. ASPS is resistant to conventional chemotherapy, with complete excision of the primary tumour and metastatectomy being the only proven modalities of treatment.1,9 ASPS however is a slow-growing tumour that follows a relatively indolent course in spite of frequent metastases at the time of presentation.10 It also has an unusual pattern of metastatic spread for a sarcoma, with the brain being a common site of metastases.1
While the radiological characteristics of primary ASPS have been described in the literature,11,12 imaging features of its metastatic pattern with respect to distribution and morphology are not widely reported. The purpose of our study was to describe the imaging features of ASPS with emphasis on the metastatic pattern."
What I learned
Nodule involvement
Nodal metastases were seen in 17/23 (74%) patients. Hypervascular intrathoracic nodal metastasis was noted in 16/23 patients (70%), all of them having concurrent lung metastases. Of the 16 patients with primary tumour in the lower extremities, metastases to the locoregional nodes (inguinal) were noted in 4 patients. Supraclavicular (3/23, 13%), pelvic (3/23, 13%) and intra-abdominal adenopathy (2/23, 9%) were the other sites of nodal disease.
http://www.ncbi.nlm.nih.gov/pmc/article ... 56157title