Celularitate

Celularitate, or cellularitate in cognate languages, is the property or state of being composed mainly of cells. In biology and medicine, the term describes the cellular density of a tissue or a sample—the proportion of its volume or area occupied by cells relative to the non-cellular components such as extracellular matrix, stroma, or fluid.

In histology and pathology, cellularitate is used to characterize tissue structure. Tissues with high cellularitate contain many cells per unit area or volume, often with relatively little extracellular material. Tissues with low cellularitate have more extracellular matrix or other non-cellular components. The concept is particularly important in evaluating biopsy specimens and in tumor pathology, where the percentage of tumor cells (tumor cellularity) can influence diagnostic interpretations and the success of molecular testing.

Measurement of cellularitate can be qualitative or quantitative. Qualitative assessments use descriptors such as low, moderate, or high cellularity, while quantitative approaches may count cells in a defined area or estimate the fraction of cells in relation to non-cellular material, sometimes aided by image analysis software or flow cytometry.

Biological and clinical relevance varies by tissue type and context. For example, certain tumors or inflammatory conditions may markedly alter cellularitate, while connective tissues can show relatively low cellularity due to abundant extracellular matrix. Understanding cellularitate helps in interpreting histological findings and planning downstream analyses. See also: cell, tissue, histology, tumor cellularity, pathology.