CASE OF THE WEEK
2019-7 / APRIL 1
(CONTRIBUTORS: YUAN GAO, KIRIL TRPKOV)
40-year-old female with a 4.5 cm solid and cystic renal mass. Images are from the radical nephrectomy specimen.
Quiz
1. What is the diagnosis?
a. Oncocytoma
b. Chromophobe renal cell carcinoma
c. Eosinophilic solid and cystic renal cell carcinoma
d. Epithelioid angiomyolipoma
e. Clear cell renal cell carcinoma, eosinophilic variant
2. What immunohistochemistry is most helpful in resolving your differential diagnosis?
a. CK7
b. CK20
c. PAX 8
d. CD 117
e. Carbonic Anhydrase IX
3. What is the typical gross/macroscopic finding of the above tumor?
a. Non-encapsulated but circumscribed, with a central scar
b. Encapsulated with area of necrosis
c. Solid with macro and micro cysts
d. Golden yellow, infiltrative with area of necrosis
e. Multiple small nodules
1. c
2. b
3. c
1. Eosinophilic solid and cystic renal cell carcinoma
2. CK20 (figure 4)
3. Solid with macro and micro cysts
Eosinophilic solid and cystic renal cell carcinoma (ESC-RCC) is a recently described emerging renal entity that is not included in the 2016 WHO classification. Most of the described cases showed indolent behavior, and the great majority present as pT1 disease. Rare cases have been documented with metastatic disease. Patients with ECS-RCC are typically females, and only rare cases have been documented in males. On gross and low power magnification, the tumor demonstrates solid and cystic composition. The neoplastic cells show voluminous eosinophilic cytoplasm with easily recognizable cytoplasmic stippling (coarse granularity). Cytokeratin 20 is diffusely positive in more than 80% of the cases, but in some cases it can be only focal. ESC-RCC is also positive for PAX8, but is typically negative for cytokeratin 7 and CD117. Approximately 10% of the patients with ESC-RCC have documented history of Tuberous Sclerosis Complex. Recently, a somatic biallelic loss or mutation of TSC1 and TSC2 have been found in ESC-RCC.
Trpkov K, Hes O, Bonert M, et al. Eosinophilic, Solid, and Cystic Renal Cell Carcinoma: Clinicopathologic Study of 16 Unique, Sporadic Neoplasms Occurring in Women. Am J Surg Pathol. 2016 Jan;40(1):60-71.
Trpkov K, Hes O. New and emerging renal entities: a perspective post‐WHO 2016 classification. Histopathology 2019, 74, 31–59.
Mehra R, Vats P, Cao X et al. Somatic bi-allelic loss of tsc genes in eosinophilic solid and cystic renal cell carcinoma. Eur Urol. 2018;74;483-486.
Yuan Gao, MD, FRCPC
Kiril Trpkov, MD, FRCPC
University of Calgary
Yuanny@gmail.com
Kidney
ESC, Eosinophilic, solid, cystic, renal cell carcinoma, unclassified