Interesting cases – GUPS : Genitourinary Pathology Society

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CASE OF THE WEEK

58-year-old woman had a left sided breast cancer, which was treated with mastectomy and chemotherapy. During the follow-up they found a mass in her left kidney. Nephrectomy was performed.

58-year-old female’s renal mass with breast cancer history.

Contributors :

Fanni Sánta, Department of Pathology, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
fanni.santa@gmail.com
Twitter: @FV_Santa

Levente Kuthi, Department of Pathology, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
kuthi.levente@med.u-szeged.hu

Quiz Questions

What is the correct diagnosis?
a) Tumor-to-tumor metastasis (breast to clear cell RCC)
b) Clear cell RCC with dedifferentiated foci
c) Collison RCC (clear cell RCC admixed with chromophobe RCC)
d) Giant cell collision in clear cell RCC
e) TFE3 rearranged renal cell carcinoma

Among the biomarkers below, what is the most specific and useful?
a) TRPS1
b) Keratin 7
c) CD68
d) ER
e) PR

Quiz Answers

1) a; 2) a

Diagnosis

Tumor-to-tumor metastasis (breast to clear cell RCC)

Discussion

Macroscopically, the tumor showed a golden-yellowish appearance on the cut surface with some hemorrhagic and necrotic foci. Histologically, the tumor was mostly composed of clear cytoplasmic cells with WHO/ISUP grade 3 morphology. Sporadically, small nests of eosinophilic cytoplasmic cells with prominent nucleoli were present. PAX8 and CA9 were positive in the clear cells, whereas the eosinophil nests showed positivity with GATA3, estrogen receptor, and TRPS1. Progesterone receptor and keratin 7 were negative in the metastatic tumor.
Metastasis of breast cancer is highly common based on their aggressive behavior. Tumor-to-tumor metastasis on the other hand is rare, which may cause confusion with the diagnosis. Based on the microenvironmental change, even the metastasis can occur easier in a secondary tumor. Although, the presence of distinct histological features between the donor and recipient tumors – for example a gastric adenocarcinoma metastasizing into a lipoma – can facilitate diagnosis, the presence of two epithelial tumors may introduce confusion. Therefore, obtaining a thorough clinical history and carefully examining the histological samples are essential.
Based on its vascularization and microenvironmental change by the VHL gene dysfunction, clear cell renal cell carcinoma is a good example of a tumor being common as both donor and receptor in tumor-to-tumor metastasis.
Clear cell renal cell carcinoma can be differentiated by its common immunohistochemical features, such as PAX8, CAIX positivity, and CK7 negativity/focal positivity. On the other hand, PAX8 can also be positive in other tumors, like serous ovarian carcinoma. CK7 can exhibit positivity in breast cancer, although negativity is also common. GATA3, SOX10 and MGB are commonly used breast markers, but they are not specific to breast cancer. On the other hand, TRPS1 shows higher sensitivity for the mammary origin.

References

Manini C, Provenza C, Andrés L, Imaz I, Guarch R, Nunziata R, López JI. Tumor-to-Tumor Metastases Involving Clear Cell Renal Cell Carcinomas: A Diagnostic Challenge for Pathologists Needing Clinical Correlation. Clinics and Practice. 2023; 13(1):288-296. https://doi.org/10.3390/clinpract13010026

Minezaki S, Misawa T, Tsukayama H, Shibuya M, Wada K, Sano K, Mochizuki M, Sasajima Y, Kondo H. Tumor-to-tumor metastasis: an extremely rare combination with renal cell carcinoma as the donor and a pancreatic neuroendocrine tumor as the recipient. Surg Case Rep. 2022 Jan 10;8(1):8. doi: 10.1186/s40792-022-01361-5. PMID: 35001202; PMCID: PMC8743331.

Almási S, Kuthi L, Sejben A, Vörös A, Nagy Á, Zombori T, Cserni G. TRPS1 expression in cytokeratin 5 expressing triple negative breast cancers, its value as a marker of breast origin. Virchows Arch. 2023 May;482(5):861-868. doi: 10.1007/s00428-023-03535-4. Epub 2023 Apr 3. PMID: 37012444; PMCID: PMC10156897.

Contributors

Fanni Sánta, Department of Pathology, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
fanni.santa@gmail.com
Twitter: @FV_Santa

Levente Kuthi, Department of Pathology, Albert Szent-Györgyi Medical School, University of Szeged, Szeged, Hungary
kuthi.levente@med.u-szeged.hu

Organ Site

Kidney

Keywords

Tumor-to-tumor metastasis; clear cell renal cell carcinoma; kidney