Abundant expression of AMACR in many distinct tumour types.

AIMS: Alpha-methylacyl-CoA racemase (AMACR), a mitochondrial and peroxisomal enzyme, is a valuable tool to confirm the diagnosis of prostate cancer, especially if combined with basal cell markers. To extend this diagnostic utility to other neoplasias, we comprehensively surveyed AMACR expression in human tumours. METHODS: We performed immunohistochemical analyses on tissue microarrays of AMACR expression in over 125 different human tumour types and 80 normal tissues. RESULTS: Microarray analysis revealed that tumours with prominent AMACR expression included adenocarcinomas of the prostate (72%), hepatocellular carcinomas (77%), papillary renal cell carcinomas (70%), and colorectal adenocarcinomas (71%). AMACR expression was equally frequent in colorectal adenomas and carcinomas. No significant difference in AMACR expression between untreated and hormone-refractory prostate cancers was observed. In the thyroid, AMACR expression was found in 42% of the follicular carcinomas but in only 16% of follicular adenomas. However, a more detailed analysis on a thyroid tissue microarray did not confirm a significant difference of AMACR expression in follicular adenoma and carcinomas. CONCLUSION: Taken together, the results indicate that AMACR is expressed in a wide variety of adenocarcinomas, and its diagnostic utility is restricted to specific areas.

Paraganglioma of the cervical sympathetic trunk.

We report the case of a 17-year-old man who presented with left-sided Horner's syndrome. Magnetic resonance imaging revealed a spindle-shaped cervical tumor in the left paravertebral space. During operation, a tumor originating from the left sympathetic trunk was found. The histopathologic analysis showed a sympathetic paraganglioma. The sympathetic trunk is an extremely rare location for a cervical paraganglioma; only a few cases have been reported in the literature.

Rare expression of BSAP (PAX-5) in mature T-cell lymphomas.

Lineage determination in lymphomas is based on the assessment of lineage-specific markers, such as the B-cell-specific activator protein of the paired box family (BSAP, PAX-5) for the B-cell lineage. BSAP is thought to be expressed exclusively in B cells from the pro-B- to the mature B-cell stage and then silenced in plasma cells. BSAP has oncogenic potential and experimental evidence shows that the T-cell lineage is prone to this effect. Herein, we report on a BSAP-positive peripheral T-cell lymphoma with monoclonal T-cell receptor gamma-gene rearrangement. To assess the relative frequency of BSAP expression in mature T-cell lymphomas, we constructed and examined a tissue microarray consisting of 43 angioimmunoblastic T-cell lymphomas and peripheral T-cell lymphomas and detected no additional BSAP-positive cases. To conclude, BSAP can probably contribute to T-cell lymphomagenesis not only in vitro, but also in vivo. It is rarely expressed in peripheral T-cell lymphoma, thus its detection on lymphoid malignancies cannot be considered definitively lineage specific.