Clear cell renal cell carcinoma with intratumoral and nodal extramedullary megakaryopoiesis: A potential diagnostic pitfall

Sean R. Williamson, Kelley J. Mast, Liangz Cheng, Muhammad T. Idrees

Research output: Contribution to journalArticle

2 Scopus citations


Clear cell renal cell carcinoma is occasionally associated with erythrocytosis, hypothesized to result from tumoral production of erythropoietin. Rarely, intratumoral erythropoiesis has been identified, although intratumoral megakaryopoiesis has not, to our knowledge, been previously described. We report the case of an 81-year-old man with myelofibrosis who underwent resection of a 9.8-cm clear cell renal cell carcinoma. Numerous megakaryocytes were present within the renal cell carcinoma; regional lymph nodes; and, to a lesser extent, the nonneoplastic kidney, glomeruli, and renal hilar soft tissue, in some areas associated with trilineage hematopoiesis. Immunohistochemistry verified the megakaryocytic lineage of the atypical cells (CD61, CD42b, and von Willebrand factor +; cytokeratin -). Intratumoral extramedullary megakaryopoiesis is a novel finding in clear cell renal cell carcinoma with potential to mimic high-grade carcinoma and involvement of lymph nodes. Careful attention to morphology, presence of other hematopoietic elements, and immunoprofile can facilitate recognition of this rare phenomenon.

Original languageEnglish (US)
Pages (from-to)1306-1309
Number of pages4
JournalHuman pathology
Issue number6
StatePublished - Jun 2014



  • Clear cell renal cell carcinoma
  • Extramedullary hematopoiesis
  • Kidney
  • Megakaryocytes
  • Myelofibrosis

ASJC Scopus subject areas

  • Pathology and Forensic Medicine

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