Mixed Epithelial and Stromal Tumor: A Rare Renal Neoplasm—Case Report with Clinicopathologic Features and Review of the Literature
Table 1
Summary of reported cases of MEST.
Authors/date
Number of cases
M : F
Age (years)
Tumor size (cm)
Histologic findings
Immunohistochemical findings
Michal M et al., 1998
1
F
48
10
Well-differentiated ducts with surrounding spindle stroma
Epithelium–Cytokeratins Stroma–HHF35, smooth muscle actin, and desmin
Adsay N et al., 2000
12
1 : 11
31–71 (mean 56)
3–12 (mean 6 cm)
Epithelium: glands–widely scattered or crowded, dilated, and showing complex branching architecture and papillae. Lined by cuboidal, flattened or hobnail cells, rare ciliated epithelium. Stroma: wide range- paucicellular fibrous to hypercellular with fascicular arrangement. Keloid-like resembling solitary fibrous tumor. Condensation of stroma around cystic epithelial component. Some cases showed prominent vasculature with thick-walled and dilated blood vessels. Fat cells (1 case)
Epithelium: cytokeratin (AE1/AE3) CAM 5.2 vimentin (4 cases) Stroma: vimentin SMA Desmin ER PR (3 cases; all female) Both epithelial and stromal component negative for S100, HMB 45, and CD34.
Michal M et al., 2004
24
1 : 11
41–75 (mean 54)
1–14 (mean 6.7)
Epithelium: cysts lined by flat to hobnail type cells. Other less frequent epithelial components include endometrioid, tubal, clear cells, and squamous type. Stroma: Spindle cells resembling ovarian stroma
Epithelium: cytokeratins variable ER and PR positivity Stroma: Vimentin. SMA, desmin (patchy), ER, PR Glands and stroma: negative for S100, chromogranin, neurofilament, synaptophysin, inhibin, and HMB45
Antic T et al., 2006
15
01 : 02.7
22-80 (mean MEST 49.7,Mean ACN 50.4
0.5-10 (mean MEST 2.9, ACN 4.3)
Epithelium: Cysts and tubules lined by flattened, cuboidal, columnar epithelium. Focal hobnail appearance. Stroma: Spindle cells With variable cellularity, myxoid, myofibroblastic, fibrous, adipocytes, and calcifications
Epithelium: positive for pan-cytokeratin (AE1/AE3), CK7, HMWCK (variable), CD10 (variable), negative for ER and PR stroma: Positive for SMA, WT1 (variable), CD34 (variable), ER (variable), PR (variable), negative for CD117, HMB 45, inhibin
Jevremovic et al., 2006
11
01 : 04.5
43–69 (mean 57)
3.2–12 (mean 6.8)
Epithelium: multilocular cysts lined by single layered epithelium. Hobnail epithelium. No epithelial atypia. Stroma: Spindle cells, ovarian-like stroma No stromal atypia.
Epithelium: pn-cytokeratin (AE1/AE3) cam 5.2 Stroma: vimentin,SMA,desmin (focal), ER, PR
Mai K et al. 2007
14
1 : 06
39–70 (mean 55+/-9)
2.5–12 (mean 5.2+/-2.9)
Epithelium: Cysts, microcysts lined by flat, columnar to hobnail cells. Rarely ciliated and urothelial-like lining cells. Stroma: Spindle cells with smooth muscle tissue, ovarian type stroma, and fibrous tissue.
Epithelium: pan-cytokeratin (AE1/AE3), CK7 ER–variable PR–variable CD10–variable Stroma: Vimentin, SMA, ER, PR, CD10, HMB45 (2 cases) (one case showing collision tumor with AML and HMB-45 positivity noted in the AML component, and second case considered PEComatous variant of MEST)
Turbiner J et al., 2007
34
1 : 16
24–84 (mean MEST 52, ACN 48)
2 to 21 (mean MEST 9.7, ACN 7.3)
Epithelium: Variable sized cysts and phyllodes like glands, lined by flat to cuboidal To hobnail cells stroma: hypocellular, hypercellular, collagenized, ovarian type, periglandular hyalinization, prominent vascularity, smooth muscle metaplasia, calcification, and hemorrhage.
Epithelium: focal positivity for CD10, ER negative for inhibin, calretinin Stroma: R, PR, CD10, inhibin (focal), calretinin
Sukov W et al., 2007
1
F
84
10.5
Showed features of malignant mixed epithelial and stromal tumor with rhabdoid features epithelium: multiple tubules and variably sized cystic structures lined by benign epithelium. Stroma: malignant appearing spindle stroma resembling ovarian stroma and stroma showing extensive rhabdoid differentiation
Epithelium: pan-cytokeratin (AE1/AE3), CK7, Cam5.2, EMA Stroma: WT1, CD99, CD56, IN1, ER, SMA (focal)
Jung et al., 2008
2
F
53 and 56
6 and 13
Case#1 Epithelium: Cysts of variable sizes lined by single layer of cuboidal cells and hobnail cells.No cytologic atypia. Tubules lined by bland cells Stroma: Spindle cells ovarian-like stroma In addition, showed malignant stroma with increased cellularity, atypia, and frequent mitoses. Case #2 Epithelial component-like case #1 Focal carcinomatous component with undifferentiated large cells Stroma: In addition to benign and malignant appearing stroma-like, case #1 also showed areas resembling fibrosarcoma, undifferentiated sarcoma, cellular myxoid sarcoma, chondrosarcoma, and rhabdomyosarcoma
Case #1 epithelium: pan-cytokeratin (AE1/AE3) Stroma: Vimentin, PR, negative for SMA, S100, ER Sarcomatous areas negative for ER and PR Case #2 epithelium: cytokeratin AE1/AE3 EMA Stroma: vimentin, PR (focal), negative for ER Rhabdomyosarcomatous areas: SMA, desmin Undifferentiated sarcomatous areas: CD99, Bcl-2, CD10, S100 Chondrosarcomatous areas: S100
Sangoi A et al., 2008
1
F
41
Bilateral tumors Right–5 Left-7.8
Right and left-sided tumors showed identical features epithelium: Glands, cysts lined by flattened to hobnail to urothelial-like cells, papillae, and phyllodes like areas. Stroma: Edematous, cellular, ovarian-like, hyalinized, smooth muscle like morphology, myxoid, calcification, and adipose tissue
Epithelium: pan-cytokeratin (AE1/AE3) cam 5.2 Stroma: ER, PR, desmin, negative for HMB45
Suzuki T et al., 2013
1
M
67
3.5
Epithelium: Cystic spaces lined by cuboidal epithelium with occasional ciliated cell stroma: Malignant stroma with atypical small round cells with a high nuclear cytoplasm ratio and spindle cells without cytologic atypia (malignant-mixed epithelial and stromal tumor of the kidney
Epithelium: ctokeratin vimentin ER PR Stroma: vimentin, Bcl-2, CD99, CD10 (<10% of cells), negative for SMA and S100
Mudaliar et al., 2014
1
F
75
8.1
(MEST with focal papillary renal cell carcinoma) Epithelium: Cysts lined by flattened to cuboidal to hobnail cells One cystic cavity lined by papillary proliferation lined with dysplastic cuboidal epithelium with variable cytologic atypia ranging from mild to frank dysplasia and necrosis. Stroma: Spindle cell, ovarian-like stroma. No stromal atypia, mitoses, or necrosis
Epithelium: CK7 CD10 (focal) papillary areas CK7 PR (focal) Stroma: vimentin, SMA, ER, PR, CD10 (focal), negative for inhibin and HMB45
Sun B et al., 2015
1
F
32
3.8
Epithelium: Variably sized cysts lined by cuboidal epithelium with focal hobnailing, without significant cytologic atypia and mitosis. Stroma: Ovarian-like stroma was condensed around the cysts and was variably cellular with areas of muscle differentiation and thick-walled vessels
Epithelium: CK19, HMWCK and alpha methyl COA racemase Stroma: SMA, desmin in areas of muscle differentiation, ER, PR, CD10, negative for HMB45
Calio A, et al., 2016
53
1 : 6.6
18–82 (median age 51)
0.3-17.5 (median 4.0)
Epithelium: Crowded glands, branching ducts, small glands with tall cuboidal cells, thyroid follicle-like glands, spatulate and complex papillae, Stroma: Hypocellular fibrous, cellular, smooth muscle, edematous, hypervascular, sclerotic walled vessels, and adipose tissue
Epithelium: ER (10%) PR (10%) CD10 (10%) PAX8 (100%), and GATA3 (57%) Stroma: SMA (97%), desmin (89%), caldesmon (88%), ER (88%), PR (95%), CD34 (47%), WT1 (26%), CD10 (90%), S100, HMB45, Melan A, PAX8, GATA3, and inhibin, SF1 (0%)
Arriola A 2018
1
M
61
11.5
Malignant MEST with 2 simultaneous renal carcinomas: Conventional papillary renal cell carcinoma (PRCC) and clear cell renal cell carcinoma (CCRCC) Epithelium: Variable sized cysts lined by flat, cuboidal to hobnailed and bland epithelial cells. Areas of conventional papillary carcinoma () and clear cell renal cell carcinoma () Stroma: Loose and cellular ovarian-like stroma. Stroma in some areas showed marked cytologic atypia and increased mitoses (up to 8 mitoses/10 high power field) and necrosis.
Epithelium: epithelium lining cystic spaces: pan-cytokeratin CK7 PAX 8 (focal) negative for CAIX PRCC: CK7 racemase negative for CAIX CCRCC: CAIX negative for CK7 and racemase stroma: vimentin SMA, negative for ER, PR, MHB45, STAT6, TLE, myogenin, and desmin
Tinguria M. 2023 (current study)
1
F
61
7.3
Epithelium: Cysts of variable sizes lined by cuboidal, columnar, and flattened epithelium with focal hobnailing. Stroma: cellular spindle cells resembling ovarian stroma. No cytologic atypia. No mitoses.
Epithelium: CK7, HMWCK, Stroma: ER, PR, CD10, SMA
Note: Cases classified as adult cystic nephroma and MEST separately in some studies have been grouped together as MEST in this table following 2022 WHO classification. ER: estrogen receptor, PR: progesterone receptor, SMA: smooth muscle actin, AML: angiomyolipoma, PEC: perivascular epithelioid cells, PRCC: papillary renal cell carcinoma, CCRCC: clear cell renal cell carcinoma, CAIX: carbonic anhydrase IX, STAT 6: signal transducer and activation of transcription (6), and TLE: transducin-like enhancer of split.
