Diagnostic Pathology (May 2010)

Early uptake and continuous accumulation of thallium-201 chloride in a benign mixed tumor of soft tissue: Case Report

  • Hamada Kenichiro,
  • Outani Hidetatsu,
  • Yoshizawa Hidenori,
  • Kubo Chiaki,
  • Yuki Michiko,
  • Tomoeda Miki,
  • Song Misa,
  • Iizuka Norishige,
  • Kitamura Masanori,
  • Yoshizato Katsuhiko,
  • Jin Yu-Fen,
  • Nagata Shigenori,
  • Araki Nobuhito,
  • Funauchi Masahiro,
  • Tomita Yasuhiko

DOI
https://doi.org/10.1186/1746-1596-5-34
Journal volume & issue
Vol. 5, no. 1
p. 34

Abstract

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Abstract A case of benign mixed tumor of the soft tissue in a 64-year-old Japanese male is presented. He noticed a painless, elastic hard mass sized 3 cm in the right knee, which gradually grew larger and harder in the last 5 years. Magnetic resonance imaging demonstrated a mass lesion embedded in the subcutaneous tissue with low and high signal intensity at T1- and T2-weighted images, respectively. Tl-201 scintigraphy showed an early uptake of Tl-201 within the lesion at 10 minutes after injection, which was slightly decreased but still continued at 2 hours later. The patient underwent a resection of tumor, and the pathological diagnosis was a benign mixed tumor of soft tissue without high vascularity, characterized by histological features similar to pleomorphic adenomas in the salivary glands. Immunohistochemical study proved expression of Na+/K+-ATPase of tumor cells. Overexpression of Na+/K+-ATPase of the tumor might be responsible for the early uptake of Tl-201, and poor vascular structure in this tumor might lead to continuous accumulation. The Tl-201 scintigraphic features of mixed tumor of soft tissue are assessed to resemble those of malignant soft tissue tumors.