Lack of ERG-antibody in Benign Mimickers of Prostate Cancer.

INTRODUCTION: Prostate carcinoma (PC) is the second most diagnosed cancer in men worldwide. Prostate tissue in needle biopsy expresses a wide variety of architectural patterns some of which are difficult to interpret. Immunohistochemical markers, such as AMACR, p63 and 34ßE12 that are currently used in diagnosing prostate cancer, are of great value, but often their interpretation is ambiguous. In 2005 Tomlins et al. identified an emerging marker, erythroblastosis E26 rearrangement gene (ERG), which is a member of the family of genes encoding erythroblast-transformation specific transcription factors (ETS) with frequent expression in PC. AIM: The aim of this study was to investigate the expression of ERG in benign mimickers of PC in needle biopsies and its diagnostic value alone and in combination with AMACK and 34ßE12. RESULTS: Of the selected 46 biopsies, two were eventually diagnosed as PC Gleason score 6 as they were simultaneously ERG and AMACR-positive and 34ßE12-negative. One case was considered atypical. The remaining 43 biopsies were diagnosed as benign cases: simple atrophy in 13 cases, partial atrophy in 11, adenosis in 9, basal cell hyperplasia in 3, post-atrophic hyperplasia in 3, clear cell hyperplasia in 2 and sclerotic adenosis in 2 cases. None of the 43 benign cores showed evidence of ERG expression. CONCLUSION: ERG could be preferably used in diagnosing prostate needle biopsies, lesions that are hard to interpret and controversial expression of AMACR/34ßE12.

Aggressive juvenile mandibular fibromatosis.

Aggressive juvenile fibromatosis of the jawbones is a rare tumor presenting as infiltrative mass with unpredictable evolution. We report herein a 17-year-old student with a 6-month history of radiologically proven resorption of a part of the mandible, lingual displacement of tooth 34 and malocclusion. Alveolar ridge resorption and three dark-brown foci in the bone were seen after the tooth was extracted. Histological study showed the tumor tissue to have a bundle-like structure; immunohistochemically it was positive for vimentin, smooth muscle actin, beta-catenin, Ki-67 (5%), and negative for desmin and cytokeratin 34bE12. The golden standard in the diagnostics of desmoid fibromatoses is the nuclear or membrane expression of beta-catenin, which is found in 90% of the cases. Differential diagnosis include mandibular fibroma, well-differentiated fibrosarcoma, fibrosing histiocytoma, and infiltration from adjacent soft-tissue tumor. Aggressive juvenile fibromatosis should be managed by radical excision. Local recurrences are not rare, but metastases do not develop. In rare cases this type of fibromatosis has been known to regress spontaneously. Aggressive fibromatosis is a diagnostic challenge, since it remains in the grey zone between benign and malignant lesions of the oral cavity.

Giant fibroadenoma of the breast.

A case of giant fibroadenoma of the breast (size 23x20x13 cm and weight 2680 grams) in a 43-year-old woman with short stature and gracile body build is presented. Pericanalicular fibroadenoma was detected histologically. One year after mastectomy the patient is in good health, with no recurrences. The case is discussed in the light of the diagnostic difficulties, which lead to radical mastectomy. Giant fibroadenomas have to be differentiated from phylloid cystosarcoma by the lack of leaf-like structures and stromal cell atypia and from the breast hamartoma and asymmetric breast hypertrophy in girls by the lack of mammary lobules. Giant fibroadenoma should take its due place in the diagnostic algorithm of the breast tumors.