D M Berney1, A Lee, S J Randle, S Jordan, J Shamash, R T D Oliver. 1. Department of Histopathology and Morbid Anatomy, St Bartholomew's and The Royal London Hospital School of Medicine and Dentistry, St Bartholomew's Hospital, London, UK. d.berney@bartsandthelondon.nhs.uk
Abstract
AIMS: To define the frequency and distribution of intratubular embryonal carcinoma (IEC) in an attempt to shed light on the pathogenesis of non-seminomatous germ cell tumours (NSGCTs). Intratubular germ cell neoplasia of unclassified type (IGCNU) is common in NSGCT; however, IEC is rarely described. METHODS AND RESULTS: Sixty-two germ cell tumours were reviewed. Immunochemistry for CD30, placental alkaline phosphatase (PLAP) and c-kit was performed. The distribution, immunohistochemistry and morphology of the intratubular neoplasia were noted. All cases showed widespread IGCNU with PLAP and c-kit staining. CD30 showed strong focal intratubular positivity in 20/31 NSGCTs, 1/29 seminomas and 1/4 mixed seminomas/NSGCTs. In 17 of these cases, the CD30+ tubules were not easily identified as IEC on routine stains. These tubules were scanty in number and c-kit was negative, though some showed patchy PLAP staining. The cells within these tubules differed morphologically from IGCNU. CONCLUSIONS: IEC defined by CD30 positivity is not always easily identified on haematoxylin and eosin staining. We suggest that IEC is a common intermediate step between IGCNU and NSGCTs. The patchy and focal distribution of IEC suggests it may evolve quickly to invasive disease.
AIMS: To define the frequency and distribution of intratubular embryonal carcinoma (IEC) in an attempt to shed light on the pathogenesis of non-seminomatous germ cell tumours (NSGCTs). Intratubular germ cell neoplasia of unclassified type (IGCNU) is common in NSGCT; however, IEC is rarely described. METHODS AND RESULTS: Sixty-two germ cell tumours were reviewed. Immunochemistry for CD30, placental alkaline phosphatase (PLAP) and c-kit was performed. The distribution, immunohistochemistry and morphology of the intratubular neoplasia were noted. All cases showed widespread IGCNU with PLAP and c-kit staining. CD30 showed strong focal intratubular positivity in 20/31 NSGCTs, 1/29 seminomas and 1/4 mixed seminomas/NSGCTs. In 17 of these cases, the CD30+ tubules were not easily identified as IEC on routine stains. These tubules were scanty in number and c-kit was negative, though some showed patchy PLAP staining. The cells within these tubules differed morphologically from IGCNU. CONCLUSIONS: IEC defined by CD30 positivity is not always easily identified on haematoxylin and eosin staining. We suggest that IEC is a common intermediate step between IGCNU and NSGCTs. The patchy and focal distribution of IEC suggests it may evolve quickly to invasive disease.