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ABSTRACT:
Azzopardi phenomenon is a histomorphologic phenomenon characterized by deposition of the basophilic material in the necrotic blood vessel walls associated with several malignant tumors. It was first correctly identified in 1959 by John G Azzopardi as DNA material associated with tumor necrosis. Azzopardi confirmed it to be DNA material that is liberated due to necrosis as it showed positive feulgen reaction. This process was considered to be seen in malignancies only, but various researches done in this field are unveiling the occurance of Azzopardi phenomenon in other diseases apart from malignancies. Still now curtain is rising in this phenomenon as various new discoveries are being added up in it.This article aims to highlight reviews in the occurrence and presence of Azzopardi phenomenon.
Key words: Azzopardi phenomenon, blood vessels, DNA, Malignancies.
INTRODUCTION
The Azzopardi effect is a histomorphologic phenomenon of incrustation of blood vessel wall with the basophilic nuclear material. It had been primarily described in small cell (neuroendocrine) carcinoma of the lung but is nonspecific and can be seen in other malignancies with a rapid cell turnover.1Foci of strongly hematoxyphilic blood vessels appearing as the result of chromatin diffusion secondary to necrosis of neoplastic tissue are sometimes referred to as the Azzopardi phenomenon.2
This phenomenon was named after John G Azzopardi, who had identified the basophilic granular material in the vessel wall as DNA, after examining cases of small cell carcinoma of lungs.3
Prior to his publication, the material was infrequently described in the literature and was presumed to be caused by calcium deposition.4
It is associated with several malignancies such as small cell carcinoma, Burkits lymphoma, Merkel cell carcinoma and Medulloblastoma. Azzopardi performed histochemical analysis using van Kossaand Alizarin red staining methods and demonstrated a positive Feulgen reaction, suggesting that the basophilic material was DNA. He concluded that this phenomenon of DNA in the vessel wall is presumably the result of deliberation of nucleic acids in large amounts from degenerating neoplastic cells.5
REVIEW
In the year 1959, John G Azzopardi examined 100 blocks of oat cell carcinoma, 32 cases showed peculiar bluish grey to the bluish black coloration of the walls of small venules. He also noted that there exists a striking association between necrosis in the tumor and the presence of...