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Int J Clin Exp Pathol 2013;6(3):498-502

Original Article
Metastatic seminomas in lymph nodes: CD10 immunoreactivity can be a pitfall of
differential diagnosis

Yasunori Ota, Kuniko Iihara, Tomiko Ryu, Teppei Morikawa, Masashi Fukayama

Department of Pathology, Toranomon Hospital, Tokyo, Japan; Department of Pathology, Social Insurance Chuo General Hospital, Tokyo,
Ja-pan; Department of Internal Medicine, Social Insurance Chuo General Hospital, Tokyo, Japan; Department of Pathology, the University of
Tokyo, Graduate School of Medicine

Received December 16, 2012; Accepted January 18, 2013; Epub February 15, 2013; Published March 1, 2013

Abstract: Metastatic seminoma can potentially be confused with lymphoma in a lymph node biopsy. Here, we report a case in which the
immunohistochemistry of CD10 was a pitfall in the differential diagnosis of a metastatic seminoma, and further present a brief study of CD10
expression in a seminoma series. A 67-year-old man, who had a history of lobectomy of the lung due to squamous cell carcinoma 2 years
prior, showed lymphadenopathy of the neck and the paraaorta on follow-up study by fluorodeoxyglucose-positron emission computer
tomography scan. The biopsy of the cervical node demonstrated infiltration of large atypical cells. The results of the screening
immunohistochemistry were CD20(-), CD3(-), CD10(+), CD30(-), AE1/AE3(-), and placental alkaline phosphatase(-), providing the impression
of CD10-positive lymphoma. However, the following studies revealed germ cell characteristics [OCT3/4(+), SALL4(+), and CLDN6(+)],
confirming the diagnosis of seminoma. We further evaluated CD10 expression in a series of seminomas (n=16). Strong positivity was
observed in 14 cases; partial and weak positivity, in 2 cases. These findings should be considered in the differential diagnosis of seminoma.
(IJCEP1212024).

Keywords: Testicular seminoma, CD10, PLAP, OCT3/4

Address correspondence to: Dr. Yasunori Ota, Department of Pathology, Toranomon Hospital, Tokyo, Japan, 2-2-2 Toranomon, Minato-ku,
Tokyo 105-8470, Japan. Phone: +81-3-3588-1111; Fax: +81-3-3560-7844; E-mail: ootay-tky@umin.ac.jp