Context.-Three-dimensional (3D) printing, a rapidly advancing technology, is widely applied in fields such as mechanical engineering and architecture. Three-dimensional printing has been introduced recently into medical practice in areas such as reconstructive surgery, as well as in clinical research. Three-dimensionally printed models of anatomic and autopsy pathology specimens can be used for demonstrating pathology entities to undergraduate medical, dental, and biomedical students, as well as for postgraduate training in examination of gross specimens for anatomic pathology residents and pathology assistants, aiding clinicopathological correlation at multidisciplinary team meetings, and guiding reconstructive surgical procedures.Objective.-To apply 3D printing in anatomic pathology for teaching, training, and clinical correlation purposes.Design.-Multicolored 3D printing of human anatomic pathology specimens was achieved using a ZCorp 510 3D printer (3D Systems, Rock Hill, South Carolina) following creation of a 3D model using Autodesk 123D Catch software (Autodesk, Inc, San Francisco, California).Results.-Three-dimensionally printed models of anatomic pathology specimens created included pancreatoduodenectomy (Whipple operation) and radical nephrectomy specimens. The models accurately depicted the topographic anatomy of selected specimens and illustrated the anatomic relation of excised lesions to adjacent normal tissues.Conclusions.-Three-dimensional printing of human anatomic pathology specimens is achievable. Advances in 3D printing technology may further improve the quality of 3D printable anatomic pathology specimens.

Cylindroma of the breast is a very rare lesion which is morphological and immunophenotypically identical to benign dermal cylindroma. We report a breast cylindroma in a previously healthy 62 year old female detected through a national breast screening program. The patient had no significant family or past medical history, and specifically no history of breast or skin diseases. The tumor consisted of well circumscribed islands of epithelial cells surrounded by a dense membrane material, and focally containing hyaline globules. At low power the islands of tumour cells formed a "jig-saw" pattern, which is typical of cylindroma, but was present within normal breast parenchyma and no had direct connection with the overlying skin. Two distinct cell populations, smaller peripheral basaloid cells and larger central cells with vesicular chromatin, were highlighted by immunohistochemistry for p63 and cytokeratin-7 respectively. Immunohistochemistry for ER, PR, and Her2/neu was negative in tumour cells. We discuss the nine previously reported cases and the distinction of breast cylindroma from adenoid cystic carcinoma, the main differential diagnosis.