J Biomed Res.  2014 Mar;15(1):49-52.

Chondroid tenosynovial giant cell tumor of the toe: A case report

• Son SM
• Lee YM
• Shin HM
• Chung JG
• Chung J
• Lee OJ

Abstract

Localized tenosynovial giant cell tumor (TGCT) usually occurs in the hand and foot regions. However, localized TGCT with extensive cartilaginous metaplasia is rare, especially in the tendon sheath of the toe. Here, we report a case of localized TGCT with cartilaginous metaplasia in a 57-year-old man. The tumor presented as a lobular mass measuring 2.2 cm in its greatest dimension and arose in the flexor digitorum tendon sheath of the right 2nd toe. Clinically, the mass was palpable 1 year ago and brought pain during walking. Microscopically, the mass was composed of focal conventional TGCT and cartilaginous components. The conventional TGCT areas consisted of mononuclear cells, multinucleated giant cells, and hemosiderin deposition. The chondroid areas were extensive and comprised more than 90% of the whole tumor. In this case, the mononuclear cells in the conventional TGCT areas showed focal immunohistochemical staining for podoplanin and S100 protein as well as diffuse staining for CD68, which is consistent with the staining pattern of conventional TGCT. The mononuclear cells in the chondroid areas were focal positive for podoplanin and diffuse positive for S100 protein. Chondroid metaplasia in diffuse TGCT has been reported in 10 cases involving the temporomandibular, elbow, and hip joints. However, there has been no report of a localized form of chondroid TGCT involving an extra-articular region.

Keyword

tenosynovial giant cell tumor; giant cell of tendon sheath; nodular tenosynovitis; chonroid, metaplasia

MeSH Terms

Elbow
Foot
Giant Cell Tumors*
Giant Cells
Hand
Hemosiderin
Hip Joint
Humans
Metaplasia
Middle Aged
Staphylococcal Protein A
Tendons
Toes*
Walking
Hemosiderin
Staphylococcal Protein A