A 23-year-old man who was an illegal immigrant was admitted to our emergency unit,
after a lengthy disembarkation process, with oliguria, constipation, vomiting, and
abdominal pain. On admission, an abdominal ultrasound showed a bulky lesion (16 × 8 cm)
that was not clearly separable from the rectum with an inhomogeneous echotexture containing
multiple anechoic areas.
To gain a better radiological assessment, a magnetic resonance imaging (MRI) scan
was performed, which demonstrated a pelvic and lower abdominal lesion with a sagittal
diameter of 25 cm and relatively sharp, convoluted edges. It extended from the rectum,
where it was in the right paramedian position, to above the transverse umbilical line,
where it was in contact with the ascending colon ([Fig. 1]). However, the diagnosis remained uncertain and because of the need to stage the
infiltration of the rectum and to spare the patient further radiation exposure, an
endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) was performed. A huge
circumferential mass in the rectum, with inhomogeneous echotexture containing multiple
anechoic areas consistent with areas of liquefaction was demonstrated ([Fig. 2]).
Fig. 1 Magnetic resonance imaging (MRI) scan demonstrating a pelvic and lower abdominal
lesion (red arrows) with a sagittal diameter of 25 cm with relatively sharp, convoluted
edges. This extended from the rectum to above the transverse umbilical line.
Fig. 2 Endoscopic ultrasound (EUS) image showing a huge circumferential mass in the rectum,
with an inhomogeneous echotexture containing multiple anechoic areas (red arrows)
consistent with areas of liquefaction.
Histological examination showed morphological and immunohistochemical appearances
consistent with the diagnosis of embryonal rhabdomyosarcoma, botryoid variety.
Once the diagnosis had been made, the patient underwent palliative surgery (abdominoperineal
amputation). The histological examination of the surgical specimen confirmed the diagnosis
of embryonal rhabdomyosarcoma. Unfortunately, a few days after the surgical intervention,
the patient died from postsurgical sepsis.
Rhabdomyosarcoma is an extremely rare malignancy of mesenchymal tissue origin. To
date, only two other cases of primary rectal rhabdomyosarcoma and very few of perianal
rhabdomyosarcoma have been described [1]
[2]
[3]. Our work indicates that rhabdomyosarcoma should be considered as a rare differential
diagnosis of an atypical rectal tumor in adults. Furthermore, we highlight the importance
of the EUS-FNA in enabling an early diagnosis of this atypical malignancy to be made.
This is the first published report of an early diagnosis of a rectal rhabdomyosarcoma
being made by EUS-FNA; therefore, we suggest this technique could be helpful in the
diagnosis of rectal masses of unknown origin.
Endoscopy_UCTN_Code_CCL_1AF_2AH
