Alveolar Soft Part Sarcoma Presenting With Cutaneous Metastases: Report of a Case With Immunohistochemical and Molecular

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Alveolar Soft Part Sarcoma Presenting With Cutaneous Metastases: Report of a Case With Immunohistochemical and Molecular Characterization


Abstract
Alveolar soft part sarcoma (ASPS) is an uncommon neoplasm of uncertain histogenesis that usually behaves as a painless, slow-growing mass that metastasizes early. We report a 21-year-old woman with cutaneous metastases of ASPS, whose histologic characteristics gave rise to a wide range of differential diagnoses of both primary and metastatic cutaneous neoplasms. The tumor failed to show a characteristic immunoprofile using routine immunohistochemical procedures, but was strongly and diffusely positive for the TFE3 antibody. The molecular study identified a type 2 alveolar soft part locus-transcription factor E3 (ASPL-TFE3) fusion, secondary to der(17)t(X;17)(p11.2;q25) translocation. A computed tomography scan performed after the diagnosis was made disclosed a 13-cm primary tumor in the left buttock. Cutaneous metastases presenting as the first sign of ASPS have not been reported previously. We emphasize the difficulties in making the diagnosis of ASPS when it presents in an unusual manner.




https://pubmed.ncbi.nlm.nih.gov/19539846/

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Cutaneous metastases presenting as the first sign of ASPS have not been reported previously. We emphasize the difficulties in making the diagnosis of ASPS when it presents in an unusual manner.

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Immunohistochemistry for Pathologists: Protocols, Pitfalls, and Tips

So-Woon Kim, Jin Roh, and Chan-Sik Park
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5122731/

Abstract

Immunohistochemistry (IHC) is an important auxiliary method for pathologists in routine diagnostic work as well as in basic and clinical research including exploration of biomarkers, as IHC allows confirmation of target molecule expressions in the context of microenvironment. Although there has been a considerable progress in automation and standardization of IHC, there are still many things to be considered in proper optimization and appropriate interpretation. In this review, we aim to provide possible pitfalls and useful tips for practicing pathologists and residents in pathology training. First, general procedure of IHC is summarized, followed by pitfalls and tips in each step and a summary of troubleshooting. Second, ways to an accurate interpretation of IHC are discussed, with introduction to general quantification and analysis methods. This review is not intended to provide complete information on IHC, but to be used as a basic reference for practice and publication.

Keywords: Immmunohistochemistry, Antigen-antibody reactions, Immunostain, Auxiliary test


CONCLUSION

IHC has become an indispensible tool for pathologists in both everyday practice and basic research for elucidating pathophysiology of the diseases. In conjunction with this, IHC is also an indispensable tool for validation in biomarker discovery that will eventually lead to a personalized medicine [31]. Even though IHC procedure has recently been automated and standardized, there are many things to be considered to optimize IHC properly and interpret appropriately. Optimization of IHC is particularly important for newly discovered molecules or new antibodies. Specificity and sensitivity of the IHC need to be validated. It is strongly recommended to review a full literature of the target molecule before starting IHC experiment [2]. Interpretation of IHC also needs to be carefully planned. Consideration for stabilizing interobserver consistency and objectifying interpretation of IHC results is crucial. In this review, we attempted to provide basic principles and practical tips for practicing pathologists and residents in pathology training.