Abstracts Posters SICOT-SOF meeting Gothenburg 2010 _2_

Poster
Topic: Tumours
Abstract number: 23846
METASTATIC CARCINOMA TO SUBCUTANEOUS TISSUE AND SKELETAL
MUSCLE
Yasuo YOSHIMURA 1 , Ken-ichi ISOBE 1 , Takeshi KOIKE 2 , Hideki ARAI 1 , Hiroyuki
KATO 1
1 Department of Orthopaedic Surgery, Shinshu University School of Medicine,
Matsumoto,Nagano Prefecture (JAPAN), 2 Department of Orthopaedic Surgery, Ina
Central Hospital, Ina,Nagano Prefecture (JAPAN)
Metastatic carcinoma to subcutaneous tissue or skeletal muscle is relatively rare, and
few studies on case-series are reported. Differentiation between primary soft tissue
sarcoma and metastatic carcinoma to soft tissue is important at presentation
because the treatments and prognoses markedly differ. We retrospectively reviewed
records of 11 patients with soft tissue metastasis in our institution from 1996 to 2009
to consider usefulness of methods for confirming diagnosis as soft tissue metastasis
and determining the primary site. In 9 cases of 10 patients who underwent MRI,
findings consisted of (1) poorly circumscribed high intensity lesions around tumor on
T2-weighted images, and (2) irregular peritumoral enhancement and (3) poorly
enhanced lesions on the center of tumor on T1-weighted images. Serum C-reactive
protein level was slightly high in 7 of 9 patients. Immunohistochemical findings of
biopsy specimens were more valuable for diagnosing as soft tissue metastasis and
determining the primary site. The expression patterns of cytokeratin 7 (CK7) and
cytokeratin 20 (CK20) and tissue-specific antibodies such as thyroid transcription
factor-1 (TTF-1), PE-10, MUC5AC, and CDX2 were particularly valuable diagnostic
markers. Although 9 of 11 patients had poorly differentiated carcinoma, the primary
site could be determined in 4 patients with CK 7 /CK 20 immunophenotype and
positivity for tissue-specific antibodies. Even in the other 5 patients, CK 7 /CK 20
immunophenotype provided useful information for determination of the primary site.
Immunohistochemical examination was thus helpful in the discrimination of primary
origin in soft tissue metastasis of carcinoma.
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