Urachal rhabdomyosarcoma in childhood: a rare entity with a poor outcome.
OBJECTIVE
Rhabdomyosarcoma (RMS) of the urachus is rare and gathered in the "abdominal and other locations" group for oncological treatment purpose, and therefore not well characterized. Our aim was to assess the clinical and prognostic specific features of urachal primary RMS in childhood.


METHODS
We retrospectively reviewed the charts of 8 patients with an urachal RMS treated between 1984 and 2013 in two Pediatric Oncology Departments. Median follow-up was 42 months (18-100).


RESULTS
Urachal RMSs were embryonal in 6, alveolar in 1, and not otherwise specified in 1. Age at diagnosis was 4.4 years (2.6-6). All patients had advanced locoregional extension (IRS IIIIV) and 1 had distant metastasis. All had chemotherapy and surgical resection. Six had external radiotherapy. Four had extensive peritoneal recurrence including 2 with distant metastasis, within a median of 25 months (11-82) after the end of treatment. One had metastatic progression under primary treatment. Four of them died between 18 and 57 months after diagnosis, and 1 is still under treatment for a late recurrence. Only 3 are free of disease after 3.3 to 7.9 years of follow-up.


CONCLUSIONS
Pediatric urachal cancer is rare and poorly identified. In our series, RMS was exclusive in this location. Locoregional extension was always advanced. Prognosis was poor despite current multimodal therapy. We underline the need for new therapeutical strategies.
Pediatric Surgery and Urology Department, AP-HP, Hopital Necker, Paris, France. Electronic address: alaa.cheikhelard@nck.aphp.fr.
Alaa
A
Cheikhelard
Pediatric Surgery and Urology Department, AP-HP, Hopital Necker, Paris, France.
Sabine
S
Irtan
Pediatric and Adolescent Oncology Department, Institut Curie, Paris, France.
Daniel
D
Orbach
Pediatric and Adolescent Oncology Department, Institut Gustave Roussy, Villejuif, France.
Véronique
V
Minard-Colin
Pediatric Surgery Department, CHU de Caen and Universite de Caen Basse-Normandie, Medical School, Caen, France.
Julien
J
Rod
Pediatric Surgery Department, AP-HP, Hopital Bicetre, Le Kremlin-Bicetre, France; HUPS, Universite Paris-Sud, Le Kremlin-Bicetre, France.
Hélène
H
Martelli
Pediatric Surgery and Urology Department, AP-HP, Hopital Necker, Paris, France; Universite Paris Descartes, Sorbonne Paris Cite, Paris, France.
Sabine
S
Sarnacki
D002648:Child; D002675:Child, Preschool; D003131:Combined Modality Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009364:Neoplasm Recurrence, Local; D011379:Prognosis; D012189:Retrospective Studies; D012208:Rhabdomyosarcoma / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy; D016019:Survival Analysis; D001749:Urinary Bladder Neoplasms / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy
Hyperthermic intraperitoneal chemotherapy (HIPEC); Laparoscopy; Pediatric oncology; Rhabdomyosarcoma (RMS); Urachus