Residency Program - Case of the Month

Clinical history:

The patient is a 56-year-old female with no significant past medical history who presented to her PMD with on going non-specific microscopic hematuria. A cystoscopy performed 10 years prior was negative. A CT ordered for further evaluation showed a 5 cm complex cyst in the right kidney at the upper pole and extending downward into the hilum. Upon referral to UC Davis Health System, an abdominal ultrasound showed a 4.5 cm isoechoic mass of the upper pole of the right kidney probably representing a hemorrhagic cyst.  A cystoscopy was also perfomed and was negative. The patient underwent a partial right nephrectomy.

Gross description:

The partial nephrectomy specimen measured 6.5 x 6 x 4 cm and was predominantly cystic. Upon sectioning a small yellow nodule measuring 1.2 x 1 x 1.2 cm was noted within a background of hemorrhagic and necrotic material. The nodule was grossly 0.8 cm from the parenchymal margin.

Microscopic photographs

Immunohistochemical stains:

Figure 1: AE1/AE3 20x

Figure 2: CAM 5.2 20x

Figure 3: VIM 20x