Uropathology
Slide seminar
Case 5
Boris Rychlý
Slovakia
• a 58-year old woman
• treated for rheumatoid arthritis for 17 years
• routine ultrasound scan - a cystic lesion of the
right kidney
• CT and MRI
• 13-mm cortical cystoid lesion
• Bosniak 2F
• watchful waiting with repeated imagings
• a year later, clear growth progression was
observed with the biggest diameter being 20mm
• post-contrast T1
• 20mm tumor in the right kidney with slight nonhomogenous enhancement
• partial nephrectomy with the safety margin
SMA
IHC
HHF35
Dezmin
CD34
CK7
Molecular genetics
• no 3p LOH by PCR
• no VHL mutation by PCR
negat.:
• CD10
• RCC
• AMACR
• TFE3
• HMB 45
Diagnosis
Clear cell tubulopapillary renal cell carcinoma
Clear cell papillary carcinoma
Renal angiomyoadenomatous tumor (RAT)
Clear cell RCC with diffuse CK7 positivity
RCC with prominent leiomyomatous proliferation
Papillary or tubulopapillary?
• clear cell papillary and clear cell tubulopillary as
synonyms
Clear cell tubulopapillary RCC
• initially reported in patients with end-stage renal
disease
• subsequently majority of cases reported as
sporadic
• clear cytoplasm, LG nuclei, low stage
• complex morphology: tubulopapillary, solid,
acinar, cystic
• possible distal tubular cell differentiation
Clear cell tubulopapillary RCC
• NO: necrosis, foamy macrophages, vascular
invasion
• linear arrangement of nuclei away from the base
(not always prominent)
• IHC
– CK7, CA-IX, HMW CK positive
– CD10, AMACR, RCC, TFE3 negative
• no consistent genetic changes (no alterations of
3p, VHL – CCRCC, no gains of chromosome 7
and 17, loss of Y – PRCC)
• so fare benign – why call it carcinoma?
Differential diagnosis
• clear cell RRC with focal papillary architecture
(wit secondary papillary formation)
• papillary CA with focal clear cells
• Xp11.2 translocation CA
• multilocular cystic renal cell neoplasm of low
malignant potential, chromophobe CA, MEST,...
Is it rare?
• forth most common (4,1%), following clear cell,
papillary, and chromophobe
• probably underdiagnosed
Is clear cell tubulopapillary CA the
same tumor as RAT?
Conclussions
• clear cell tubulopapillary – distinct tumor
(morphology + IHC)
• next WHO
• not so rare / underdiagnosed
• indolent (probably benign)
thank you for your attention