3-DIMENSIONAL ANATOMY OF COMPLETE DUCT SYSTEMS IN HUMAN BREAST - PATHOLOGICAL AND DEVELOPMENTAL IMPLICATIONS

Aims-To reconstruct the arrangement in space of all major ducts and th eir branches from nipple to periphery of a human breast obtained at ne cropsy. Methods-Duct tracing through cleared haematoxylin stained 2 mm sub-gross coronal slices of a complete necropsy breast and computer m odelling of duct territories. Results-All branches were traced for 10 complete duct systems of a single breast from a 19 year old girl. Thei r complexity prevented comprehensive modelling of individual ducts and rami using available computer software, but the territories (catchmen ts) drained by individual duct systems did not overlap and could be re constructed. Catchment volume and length of the central unbranched duc t draining each catchment varied greatly. Duct spacing showed non-rand om unformity which is also seen in rodent mammary glands. Conclusions- These spatial relations are consistent with mutual growth inhibition b etween duct systems during mammary development. Although there is no c lear morphological distinction between mammary duct end buds and later al buds in women, the present study does suggest that processes of bra nching morphogenesis occurring during development of the breasts in wo men do show some analogies with the growth of end buds/lateral branche s/alveoli during rodent mammary gland development. Rodent models of ma mmary development may usefully suggest hypotheses about human breast b iology. Less laborious methods of three dimensional reconstruction of mammary ducts and their branches from sub-gross slices, allowing more specimens to be studied, would be valuable for the study of normal hum an breast development and mammary intraepithelial neoplasia. Increasin g power and decreasing costs of high definition image processing hardw are and software may make such endeavours practicable.