Assessing the Quality of Long-Term Stored Tissues in Formalin and in Paraffin-Embedded Blocks for Histopathological Analysis.

Introduction: Formalin is the most commonly used fixative which enables for long-term storage of specimens and preserves morphologic features allowing the microscopic evaluation for future research analysis. Archival collections of the tissue serve as a reliable tool for diagnostic research purpose. They have an important role in on-going patient care, allows for evaluation of recurrent cases for diagnostic purpose and rare case specimens can also be used as an educational tool as well as for further biomedical research purposes.

Unusual Association of Calcifying Cystic Odontogenic Tumor with Compound Odontoma and Ameloblastoma: Case Report and Review of the Literature.

Calcifying cystic odontogenic tumor (CCOT) is a rare odontogenic cyst accounts for <2% of all odontogenic cysts. Simple unicystic CCOT is commonly encountered accounts for 65%, whereas other forms of CCOT are <3%. CCOT is associated with two or more odontogenic tumors, it is called combined odontogenic lesions or hybrid lesions.

Comparison of staining adequacy between tissues stored in formalin and paraffin embedded blocks for prolonged duration.

Introduction: Tissues submitted for histopathological diagnoses are routinely fixed in formaldehyde fixative which facilitates tissue storage for the extended period of time for further investigation or research purpose. The literature has reliable data relating to immunohistochemistry and molecular studies done using tissue fixed in formalin for longer duration and in paraffin-embedded tissue blocks. We have attempted to evaluate staining adequacy of archival specimens using hematoxylin and eosin (H&E) and trichrome stains.