Renal cell carcinoma (adenocarcinoma)

General: Tumours arise from tubular epithelium

Epidemiology: Occur in 6^th-7^th decades of life, male: female / 3:1, Risk factors: smoking, obesity, hypertension, unopposed oestrogen therapy, asbestos, chronic renal failure, polycystic disease, tuberous sclerosis.

Clinical features / course: classic: costovertebral pain, palpable mass, haematuria (classic tri-symptoms in 10% of cases only). Usually, tumour is silent until very large (10cm) ≫ systemic symptoms (LOW, LOA). Renal cell carcinoma also produces paraneoplastic syndromes such as: hypercalcaemia, hypertension, polycythaemia, Cushings etc.

Morphology: Macroscopic: upper pole nodules, yellow-white colour, areas of haemorrhage + necrosis. Microscopic: There are three types of renal cell carcinomas: clear cell, papillary, chromophobes. Clear cell (80%): rounded cells, clear cytoplasm, well differentiated/marked nuclear atypia (depends on cancer). Papillary (10-15%): tumour cells (cuboidal/columnar cells) arranged in papillary form, interstitial foam cells, psammoma bodies. Chromophobe (5%): sheets of pale cells, perinuclear halo.

Genetics / Cytogenetics: Clear cell carcinoma: There is deletion of the VHL gene from chromosome 3. VHL gene acts as a tumour suppressor gene. Papillary: Trisomies 7, 16, 17 and loss of Y in male patients≫ sporadic forms, and trisomy 7 ≫ familial form. Chromophobe: multiple chromosome losses.

Behaviour: Unfortunately, most patients are asymptomatic ≫ and by the time it produces local symptoms it has already metastasized. Metastatic locations: lungs, bone, nodes, liver, brain. Striking patterns is invasion into renal vein (varicosities of scrotal veins).

Prognosis & Treatment: Chromophobe renal carcinoma has best prognosis compared to other two. Treatment is usually nephrectomy.

Category: Pathology Notes