Case presentation
An 80-year-old woman, with a medical history of hypertension and
dyslipidemia, was diagnosed incidentally with a left renal mass on an
abdominal computed tomography (CT) scan performed mainly to investigate
acute abdominal pain. The CT scan showed a heterogeneous renal cyst with
regular contours, in the renal medulla and it was classified Bosniak 4.
Then, the patient underwent an enlarged left nephrectomy.
Macroscopically, it was a fairly well-defined nodular formation,
grayish-white with ocher-yellow foci. It measured 3 cm and it was
located in the renal medulla (Figure 1). Histological examination found
tubular formations merging with bland spindle cells and a mucinous
stroma (Figure 2). Tumour cells express CK7 and AMACR (Figure 3, 4). The
tumour was classified pT1N0M0. The outcome was favourable, free of
recurrence or complications after eight months of follow-up.