Soft Tissue Chordomas: An Analysis of 11 Cases
Scott R Lauer, Jerad M Gardner, Anita Sebastian, Sharon W Weiss, Mark A Edgar. Emory University School of Medicine, Atlanta, GA
Background: The existence of histologically classic chordoma of soft tissue has been questioned as many presumptive cases have been reclassified as parachordoma/myoepithelioma. Utilizing the biomarker brachyury, we have analyzed our experience with 11 cases to validate its existence and define its features.
Design: Departmental and consultation files were searched from 1989-2011 for cases diagnosed as “parachordoma” or “chordoma” arising in soft tissue. Cases were excluded if bone involvement was documented radiologically/surgically, if the patient had a known skeletal chordoma, and/or if the histologic/immunohistochemical features were not typical. Patient age, gender, tumor location and size, and follow up information were noted. Immunostains for brachyury, S100 protein, and cytokeratin were performed.
Results: Eleven of 27 cases met inclusion criteria. There were 9 males and 2 females with ages ranging from 13-71 yrs (mean 44 yrs). Tumors were located on buttock (n=2), wrist (n=2), leg (n=2), toe (n=1), thumb (n=1), ankle (n=1), shoulder (n=1), and chest wall (n=1), ranged in size from 0.5 to 10.9 cm (mean 4.3 cm), and consisted of cords and syncytia of spindled/epithelioid cells with partially vacuolated eosinophilic cytoplasm situated within a myxoid background. Tumors were positive for brachyury (9/9), cytokeratin (10/10), and S100 protein (9/10). Follow up information was obtained in 10 patients with a mean follow up period of 69 months (range 2-212 months). Two patients developed local recurrence (chest wall and leg) and lung metastases, one of whom also developed intrabdominal metastases. A third patient with a buttock primary developed lung metastasis alone. No patient with a distal lesion developed metastasis. Intervals to local recurrence and lung metastasis ranged from 23 to 162 months and 2.5 to 76 months, respectively. One patient died with an unknown disease status; the remainder (n= 7) were alive with no evidence of disease.
Conclusions: 1. Soft tissue chordomas share histologic and immunohistochemical features identical to skeletal chordomas. 2. Distal soft tissue chordomas comprise approximately one half of cases and may have a better prognosis than proximal ones. 3. The existence of soft tissue chordomas implies notochordal remnants are not a prerequisite for chordoma development.
Category: Bone & Soft Tissue
Tuesday, March 20, 2012 11:30 AM
Platform Session: Section G, Tuesday Morning