Table of Contents
Definition / general | Terminology | Epidemiology | Sites | Clinical features | Case reports | Treatment | Clinical images | Microscopic (histologic) description | Microscopic (histologic) images | Differential diagnosisCite this page: Hale CS. Deep penetrating nevus. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/skintumormelanocyticdeeppennevus.html. Accessed March 4th, 2021.
Definition / general
- Very cellular melanocytic nevus consisting of spindled melanocytes extending into reticular dermis or subcutis (Arch Dermatol 1993;129:328)
Terminology
- Focal atypical epithelioid components (clonal nevus) may be a related entity (J Am Acad Dermatol 2006;55:460)
Epidemiology
- Uncommon lesion, first reported in 1989 (Am J Surg Pathol 1989;13:39)
- Slight female predominance (1.3:1)
- Usually appears before age 50 (Arch Pathol Lab Med 2011;135:321), range 3-56 years (mean 26 years, Histopathology 2003;43:529)
Sites
- Usually face, neck, shoulder; not acral skin (Arch Pathol Lab Med 2011;135:321)
Clinical features
- < 1 cm
- May resemble melanoma (J Plast Reconstr Aesthet Surg 2007;60:1252)
Case reports
- 25 year old man with linear arrangement of multiple deep penetrating nevi (Arch Dermatol 2003;139:1608)
- Deep penetrating nevus of cheek skin (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2007;104:e49)
- Unconventional deep penetrating melanocytic nevus with microscopic involvement of regional lymph nodes (J Cutan Pathol 2012;39:25)
Treatment
- Simple excision; only rarely recurs (Histopathology 2003;43:529)
Microscopic (histologic) description
- Nevus whose dermal component extends into reticular dermis or subcutis
- Cellular, nested or fascicular with abundant pigment and mild atypia
- Usually inconspicuous junctional component
- Plump regular nests of melanocytes in dermis
- Mild cytologic atypia with some nuclear pleomorphism, small to medium-sized eosinophilic nucleolus (Arch Pathol Lab Med 2011;135:321)
- Occasional normal dermal mitotic figures, patchy mononuclear inflammatory cell infiltrate
- Absence of maturation
- May be combined with other nevi
Microscopic (histologic) images
Differential diagnosis
- Melanoma - vertical growth phase: mitotic figures and marked atypia, ATM immunostaining may differentiate (Cancer Epidemiol Biomarkers Prev 2007;16:2486)