Alveolar soft part sarcoma of the orbit: A case report

Alveolar soft part sarcoma is a rare soft tissue neoplasm that accounts for approximately 1% of all sarcomas and is usually identified in the extremities in adults. The occurrence of alveolar soft part sarcoma in the orbit is extremely rare, estimated at approximately 5% – 15% among all cases of alveolar soft part sarcoma . Here, we present a case of 29-year-old woman with orbital alveolar soft part sarcoma. We describe the magnetic resonance and F-18 2-fluoro-2-deoxy-D-glucose-position emission tomography/computed tomography findings of this case. This young woman had a spindle-shaped mass. A higher signal compared to the extraocular muscle on T1-weighted images, numerous flow voids on T2-weighted images, and intense enhancement could be key findings of this disease.

Radiologic-Pathologic Correlation of Primary Retroperitoneal Neoplasms

An earlier incorrect version of this article appeared in print. The online version is correct.

Imaging and Pathological Features of Alveolar Soft Part Sarcoma: Analysis of 16 Patients

Context  Alveolar soft part sarcoma (ASPS) is a rare soft tissue tumor most commonly occurring in deep intramuscular plane of lower extremities of adolescents and young adults. It is a highly vascular, slow growing tumor with malignant potential having lung as the most common site of metastases at the time of presentation. Aims  The aim is to review the imaging findings of ASPS and determine characteristic imaging features of this rare tumor. Materials and Methods  Sixteen patients having histopathological diagnosis and preoperative imaging of ASPS attending the dedicated sarcoma clinic at our institute were included in the study. The demographic, clinical, and imaging data were retrieved from the case records and then evaluated for characteristic imaging features which may raise suspicion of ASPS. Results  The patients ranged from 3 to 72 years of age and with a slight male preponderance. Of the eight CECTs evaluated, 62.5% tumors showed well-defined lobulated margins, 87.5% cases showed intense enhancement with presence of feeder vessels. On CEMRI of 10 patients, 70% had well circumscribed lobulated margins with intense enhancement and tortuous flow voids in most of them. All cases showed T2 hyperintense signal. Fourteen of 16 (87.5%) patients had metastatic disease with lung as the most common site (92.8%). Conclusion  ASPS is a rare soft tissue sarcoma seen in children and young adults. Imaging may mimic a vascular malformation due to the presence of tortuous feeders. Misdiagnosis at an early stage may lead to later metastatic presentation of the disease, thus emphasizing the need to suspect it on imaging.

Clinical presentation and CT/MRI findings of alveolar soft part sarcoma: a retrospective single-center analysis of 14 cases

BACKGROUND

Alveolar soft part sarcoma (ASPS) is a relatively rare malignant tumor and early diagnosis and appropriate treatment for ASPS are essential for a good prognosis.

PURPOSE

To retrospectively review the clinical presentation and computed tomography (CT) and magnetic resonance imaging (MRI) findings of ASPS so as to improve the accuracy of imaging diagnosis.

MATERIAL AND METHODS

Fourteen patients with pathologically proven ASPS were enrolled. Their clinical and imaging findings were retrospectively reviewed.

RESULTS

The median age of the patients was 29 years (range, 13-37 years). Most tumors were located in the soft tissues of the trunk and lower limbs. The median maximal diameter of the masses was 91 mm. Thirteen masses presented with ovoid or irregular shapes. Eleven masses had less clear boundaries. Compared with the adjacent muscles, the masses were isodense or hypodense on CT, hypo-, iso-, or hyperintense on T1-weighted images, and heterogeneous hyperintense on T2-weighted images. Intense enhancement was seen after contrast agent administration, with prominent intra- or peri-tumoral feeders on CT or flow voids on MRI. By the end of the last follow-up, 13 patients had distant metastasis and three patients had local recurrence.

CONCLUSION

ASPS should be included in the differential diagnosis when a bulky, heterogeneous soft tissue mass in the trunk and the lower limbs with intense enhancement after contrast administration and prominent intra- or peri-tumoral feeders on CT or flow voids on MRI is seen, particularly in young patients.