Abstract:

Background: Bones are hard tissue forming of body skeleton, composed of 60% inorganic component (hydroxyapatite), 10% water and 30% organic component. Skeletal bones can host numerous types of cancers, they account for less than 1% of diagnosed cancers each year and are associated with significant morbidity and mortality. In routine histopathology, the Study of fibrilar, cellular and sub cellular structures of mineralized tissues like bones is only possible after the removal of the calcium apatite of these hard tissues by the process of demineralization (decalcification) using different decalcifying agents such as acids and chelating agents. Currently there is no local study that shows the efficacy of different decalcifying agent, though there are striking differences in calcium (Ca) and phosphorus (P) metabolism between ethnic groups

Objectives: This study intended to evaluate the efficacy of different decalcifying agent by identifying fastest decalcifying agents, effects of agents on integrity of the bones tissue, and staining characteristics of the bones decalcified in the different decalcifying agents.

Methodology: Prospective descriptive laboratory-based study will be conducted on post mortem bone tissue in CPL at Bugando Medical Centre from April to August 2023. Specimen meet standard were sorted, decalcified, processed, stained and observed microscopically according to BMC Central pathology laboratory standard guideline. A budget of about 801,000 Tshs was used in this research.

Result: A total number of 55 bone tissue samples were enrolled in this study, Nitric acid was the fastest agent which took 1.59 ± 0.65 days while ethylene diamine tetracetic acid was slowest agent which took 20.10 ± 1.52 days for complete decalcification, tissue decalcified by EDATA and nitric acid were easy to cut, scored 29.70 and 29.15 respectively, Second best agent during cutting were hydrochloric acid scored 29.7 followed by formic acid with 27.15 scores and the last decalcifying agent that showed poor effect on many tissue texture were trichloroacetic acid which scored 26.68 scores. Decalcifying agent with high performance on overall demonstration of cellular features through staining characteristics was EDTA with 16.45 scores, and agent which was poor on demonstration of staining features was trichloroacetic acid scored 13.45 scores.

Conclusion: Histological sections impressions depend on a variety of factors which includes fixation, tissue processing, sectioning and staining timings. The final results led to the proposition that EDTA was indeed the best decalcifying agent and should be used if time factor is not essential. In case of time become relevant for example if surgeon depend on pathologist output for patient management, 10% nitric acid can be used due to its fastest action and good staining features.