TY - CHAP M1 - Book, Section TI - Nodular and Diffuse Cutaneous Infiltrates A1 - T. Desman, Garrett A1 - Harvell, Jeff D. A1 - Barnhill, Raymond L. A2 - Barnhill, Raymond L. A2 - Crowson, A. Neil A2 - Magro, Cynthia M. A2 - Piepkorn, Michael W. A2 - Kutzner, Heinz A2 - Desman, Garrett T. Y1 - 2020 N1 - T2 - Barnhill's Dermatopathology, 4e AB - Nodular and diffuse dermal cellular infiltrates encompass a wide spectrum of infectious and noninfectious dermatitides as well as neoplasms. Nodular infiltrates produce discrete cellular aggregations that are separated by relatively normal dermis. Diffuse infiltrates tend to involve the entire breadth of a biopsy. They may be relegated to either the upper, middle, or lower portion of a specimen or can be confluent. Combined nodular and diffuse patterns of infiltration may also be present in some conditions. Additionally, tropism for adnexal structures, such as hair follicles and sweat ducts as well as nerve bundles, may characterize some diseases. By definition, this histopathological category exhibits absent to minimal epidermal involvement. This chapter will focus mainly on inflammatory diseases, dermatoses, and some entities in which the true nature of the infiltrate is not precisely defined (inflammatory vs neoplastic). Although many neoplasms may display these patterns (eg, melanocytic proliferations, metastatic tumors), they will be treated mainly as differential diagnoses that are discussed in depth in other sections of this book. SN - PB - McGraw Hill Education CY - New York, NY Y2 - 2024/03/28 UR - dermatology.mhmedical.com/content.aspx?aid=1178388658 ER -