Comparison of retroperitoneal liposarcoma extending into the inguinal canal and inguinoscrotal liposarcoma

Background This study was designed to analyze differences between retroperitoneal liposarcoma (RLPS) extending into the inguinal canal and inguinoscrotal liposarcoma. Methods We retrospectively reviewed the records for patients who were managed for inguinal liposarcoma at Samsung Medical Center, a tertiary hospital, between January 1998 and December 2016. Patient data on demographics, tumour location, surgery, adjuvant therapy, histology, recurrence and death were collected. We used Mann-Whitney, Fisher exact and Kaplan-Meier log-rank tests to analyze differences between groups. Results Seven of 179 (3.9%) patients with abdominal liposarcoma had inguinoscrotal liposarcoma, and 6 of 168 (3.6%) patients with RLPS had extension to the inguinal canal. No differences were observed between groups in sex (p > 0.99), mean age (49.7 6.4 yr v. 52.1 12.5 yr, p = 0.37), laterality (p > 0.99) or scrotal involvement (40.0% v. 66.7%, p = 0.57). The RLPS group had significantly larger tumours than the inguinoscrotal group (27.9 6.8 cm v. 7.8 4.2 cm, p = 0.001). Postoperative complications were significantly more common in the RLPS group (n = 4, 83.3%); patients in the inguinoscrotal group experienced no postoperative complications (p = 0.021). Log-rank tests showed that the groups had no statistical differences in disease-free survival (p = 0.94) or overall survival (p = 0.10). However, inoperable disease-free survival was significantly poorer in the RLPS group (p = 0.010). Conclusion Although initial signs and symptoms can be similar, RLPS extending into the inguinal canal was associated with significantly higher morbidity and mortality than inguinoscrotal liposarcoma. Contexte Cette etude visait a examiner les differences entre le liposarcome retroperitoneal s'etendant au canal inguinal et le liposarcome inguino-scrotal. Methodes Nous avons procede a une analyse retrospective des dossiers de patients traites pour un liposarcome inguinal au Samsung Medical Center, un hopital de soins tertiaires, entre janvier 1998 et decembre 2016. Nous avons recueilli les donnees des patients en ce qui a trait aux caracteristiques demographiques, au siege de la tumeur, a la chirurgie, au traitement adjuvant, a l'histologie, a la recidive et au deces. Nous avons utilise le test de Mann-Whitney, la methode exacte de Fisher et les tests logarithmiques par rangs de Kaplan-Meier pour analyser les differences entre les 2 groupes. Resultats Sept des 179 (3,9 %) patients atteints de liposarcome abdominal avaient un liposarcome inguino-scrotal, et 6 des 168 (3,6 %) patients atteints de liposarcome retroperitoneal presentaient une extension au canal inguinal. Aucune difference n'a ete observee entre les groupes pour le sexe (p > 0,99), l'age moyen (49,7 +/- 6,4 ans c. 52,1 +/- 12,5 ans, p = 0,37), la lateralite (p > 0,99) ou l'atteinte scrotale (40 % c. 66,7 %, p = 0,57). La taille de la tumeur etait significativement plus grande dans le groupe du liposarcome retroperitoneal que dans celui du liposarcome inguino-scrotal (27,9 +/- 6,8 cm c. 7,8 +/- 4,2 cm, p = 0,001). De meme, les complications postoperatoires etaient significativement plus courantes dans le groupe du liposarcome retroperitoneal (n = 4, 83,3 %), les patients du groupe du liposarcome inguino-scrotal n'en ayant pratiquement pas presente (p = 0,021). Les tests logarithmiques par rangs ont revele l'absence de differences statistiques entre les groupes pour la survie sans recidive (p = 0,94) et la survie globale (p = 0,10). Cependant, la survie sans recidive du patient inoperable etait significativement plus faible dans le groupe du liposarcome retroperitoneal (p = 0,010). Conclusion Malgre la similarite des premiers signes et symptomes, le liposarcome retroperitoneal s'etendant au canal inguinal etait associe a des taux de morbidite et de mortalite significativement plus eleves que le liposarcome inguino-scrotal.