Case report:
A 68-year-old female with no medical history presented with a complaint
of an abdominal painless mass. She has no associated urinary or
digestive signs (as nausea, vomiting, dyspepsia or constipation).
Physical examination showed a large hard non-mobile non-tender mass in
the right hemi abdomen and extending from the subhepatic region down to
the right pelvis. Laboratory findings and tumor markers were within the
normal range. Computed tomography showed a voluminous retroperitoneal
mass of 26 x 14 cm encasing entirely the right kidney (figure 1). It had
a mixed content, mainly of fat density and some microcalcifications. The
intestinal loops and other abdominal organs were displaced to the
midline without any signs of tumoral invasion. The Ct-scan didn’t show
any liver or pulmonary metastasis.
The patient underwent a midline laparotomy: a bulky, well-encapsulated
mass was found arising from the right perinephric area and englobing
entirely the right kidney. The tumor measuring 20 x 30 x 15 cm was
totally excised en-bloc with the right kidney (figure 2). The radical
nephrectomy was necessary to achieve clear macroscopic resection margins
without any tumoral capsule break-in.
The patient had an uncomplicated postoperative course and was discharged
to home on the 6th postoperative day.
Histological and immunohistochemistry analysis of the tumor revealed a
dedifferentiated RLS with no evidence of tumor invasion of the kidney.
Then, the patient had an adjuvant radiotherapy. After 18 months
follow-up, the patient has no clinical or radiological signs of disease
recurrence.