Calretinin expression in human normal and neoplastic tissues: a tissue microarray analysis on 5233 tissue samples.

Area of Science:

• Oncology
• Pathology
• Biochemistry

Background:

• Calretinin is a calcium-binding protein with known expression in various tissues.
• Previous research indicated calretinin's utility in distinguishing lung adenocarcinomas from malignant mesotheliomas.
• However, calretinin expression has been observed in other tumor types, complicating its diagnostic specificity.

Purpose of the Study:

• To systematically investigate the prevalence and patterns of calretinin expression across a wide range of normal and neoplastic human tissues.
• To evaluate the diagnostic utility of calretinin as a marker in different cancer types.

Main Methods:

• Utilized tissue microarrays (TMAs) for high-throughput analysis.
• Performed immunohistochemical detection of calretinin expression.
• Analyzed 5233 tissue samples encompassing 128 tumor categories and 76 normal tissue types.

Main Results:

• Calretinin expression was detected in 58% of tumor types (weak) and 36% (strong).
• Strong expression in normal tissues included Leydig cells, neurons, ovarian theca cells, and mesothelium.
• Strong calretinin expression in tumors was most common in malignant mesotheliomas, Leydig cell tumors, adrenal adenomas, and adenomatoid tumors.

Conclusions:

• Calretinin is broadly expressed across numerous tumor types, extending beyond its initial diagnostic associations.
• The widespread expression of calretinin in neoplastic tissues requires careful consideration of differential diagnoses, particularly for pleural tumors.
• Metastatic disease should be included in the differential diagnosis for calretinin-positive pleural lesions.