Clinical outcome of dedifferentiated liposarcoma in the extremities: A retrospective case series of 7 patients.
BACKGROUND
Wide resection is the generally recommended surgical treatment for dedifferentiated liposarcoma (DDLPS) in the extremities. However, it may be appropriate to distinguish the surgical margin of low-grade atypical lipomatous tumor (ALT)/well-differentiated liposarcoma (WDLPS) area from the high-grade dedifferentiated area, because the low- and high-grade areas can be clearly separated, both radiologically and histologically. This study re-evaluated the details of surgical margin of DDLPS in the extremities, and aimed to investigate the optimal surgical margin and the usefulness of adjuvant therapy for DDLPS in the extremities.


METHODS
Seven patients diagnosed with DDLPS in the extremities and treated between 1995 and 2013 were analyzed. The use of adjuvant therapy before and after surgery was assessed, and the surgical margins for the ALT/WDLPS and dedifferentiated areas were re-evaluated by using the specimens resected at surgery. Subsequently, the recurrence rates, metastatic rates, and oncological outcomes were examined.


RESULTS
Four and three patients had wide (adequate wide margin, n = 3; inadequate wide margin, n = 1) and marginal margins for the dedifferentiated area, respectively, while three and four patients had wide (adequate wide margin, n = 2; inadequate wide margin, n = 1) and marginal margins for the ALT/WDLPS area, respectively. Postoperative radiotherapy was performed in three patients with an inadequate wide margin or a marginal margin for the dedifferentiated area. No patient had local recurrence. Distant metastases occurred in two patients. These patients died of their disease. The other five patients were disease-free.


CONCLUSIONS
The ALT/WDLPS and dedifferentiated areas in the tumor margin may be better to be considered separately in determining the appropriate resection extent for DDLPS in the extremities. Postoperative radiotherapy may provide good local control for cases with a narrow surgical margin.
Department of Orthopaedic Surgery, Shinshu University School of Medicine, Japan. Electronic address: mune0527@yahoo.co.jp.
Munehisa
M
Kito
Department of Orthopaedic Surgery, Shinshu University School of Medicine, Japan.
Yasuo
Y
Yoshimura
Department of Orthopaedic Surgery, Matsumoto Medical Center, Chushin-Matsumoto Hospital, Japan.
Ken'ichi
K
Isobe
Department of Orthopaedic Surgery, Shinshu University School of Medicine, Japan.
Kaoru
K
Aoki
Department of Orthopaedic Surgery, Shinshu University School of Medicine, Japan.
Shuichiro
S
Suzuki
Department of Orthopaedic Surgery, Shinshu University School of Medicine, Japan.
Atsushi
A
Tanaka
Department of Orthopaedic Surgery, Shinshu University School of Medicine, Japan.
Masanori
M
Okamoto
Department of Anatomic Pathology, Shinshu University School of Medicine, Japan.
Kenji
K
Sano
Department of Orthopaedic Surgery, Shinshu University School of Medicine, Japan.
Hiroyuki
H
Kato
D000368:Aged; D000369:Aged, 80 and over; D001707:Biopsy, Needle; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry; D007564:Japan; D008080:Liposarcoma / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery*; D035002:Lower Extremity; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000469:parasitology* / Q000601:surgery; D012189:Retrospective Studies; D018570:Risk Assessment; D012494:Sampling Studies; D012983:Soft Tissue Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery*; D013997:Time Factors; D016896:Treatment Outcome; D034941:Upper Extremity