A case of giant cell-rich solitary fibrous tumor in the external auditory canal

Sayaka Yuzawa, Satoshi Tanikawa, Isamu Kunibe, Hiroshi Nishihara, Kazuo Nagashima, Shinya Tanaka

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

We present a rare case of giant cell-rich solitary fibrous tumor (SFT) arising at the left external auditory canal in a 31-year-old woman. The tumor was well-circumscribed and composed of spindle-shaped cells with abundant collagenous bands. Scattered multinucleate giant cells were observed, some of which lined pseudovascular spaces. Although a focal mild-hypercellular area was observed, mitoses were rare and necrosis was absent. Interstitial mast cells were scattered, especially in the hypercellular area. Immunohistochemically, CD34, vimentin, and Bcl-2 presented diffuse positivity. Moreover, both mononuclear spindle cells and multinucleate cells showed nuclear STAT6 positivity, while NAB2-STAT6 fusion gene could not be detected by reverse transcription polymerase chain reaction using formalin-fixed specimen. These findings suggest the pathological diagnosis of giant cell-rich SFT, previously known as giant cell angiofibroma, which is a rare variant of SFT with multinucleate giant cells and occurs predominantly in orbital region. Although giant cell-rich SFTs of extra-orbital sites have been reported, to our knowledge, this is the first case arising in the external auditory canal. Giant cell-rich SFT should be considered as a differential diagnosis of spindle cell lesion with multinucleate giant cells, and STAT6 immunohistochemistry should be performed to distinguish this rare tumor from other mesenchymal neoplasms.

Original languageEnglish
Pages (from-to)701-705
Number of pages5
JournalPathology international
Volume66
Issue number12
DOIs
Publication statusPublished - 2016 Dec 1
Externally publishedYes

Fingerprint

Solitary Fibrous Tumors
Ear Canal
Giant Cells
Angiofibroma
Neoplasms
Gene Fusion
Vimentin
Mitosis
Mast Cells
Formaldehyde
Reverse Transcription
Differential Diagnosis
Necrosis
Immunohistochemistry
Polymerase Chain Reaction

Keywords

  • external auditory canal
  • giant cell angiofibroma
  • NAB2
  • solitary fibrous tumor
  • STAT6

ASJC Scopus subject areas

  • Pathology and Forensic Medicine

Cite this

A case of giant cell-rich solitary fibrous tumor in the external auditory canal. / Yuzawa, Sayaka; Tanikawa, Satoshi; Kunibe, Isamu; Nishihara, Hiroshi; Nagashima, Kazuo; Tanaka, Shinya.

In: Pathology international, Vol. 66, No. 12, 01.12.2016, p. 701-705.

Research output: Contribution to journalArticle

Yuzawa, S, Tanikawa, S, Kunibe, I, Nishihara, H, Nagashima, K & Tanaka, S 2016, 'A case of giant cell-rich solitary fibrous tumor in the external auditory canal', Pathology international, vol. 66, no. 12, pp. 701-705. https://doi.org/10.1111/pin.12470
Yuzawa, Sayaka ; Tanikawa, Satoshi ; Kunibe, Isamu ; Nishihara, Hiroshi ; Nagashima, Kazuo ; Tanaka, Shinya. / A case of giant cell-rich solitary fibrous tumor in the external auditory canal. In: Pathology international. 2016 ; Vol. 66, No. 12. pp. 701-705.
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