Melanoma, Nodular Type
Soheil Sam Dadras, MD, PhD
Nicole Carreau
Key Facts
Terminology
Nodular, predominantly dermal invasive melanoma
Clinical Issues
Elevated, firm, rapidly growing nodule
Microscopic Pathology
Junctional component is small, and nodule may be separated from epidermis
Areas of nodular/sheet-like growth pattern
Epithelioid cell morphology with vesicular nuclei, prominent nucleoli
Pleomorphic nuclei with hyperchromasia
Mitoses often numerous, present deep in dermal component
Top Differential Diagnoses
Superficial spreading type of invasive melanoma
Spitz nevus
Metastatic melanoma (with epidermotropism)
 Clinical photograph of a nodular-type melanoma shows a darkly pigmented elevated lesion with irregular borders on the chest. (Courtesy J. Wu, MD.) |
 Low-power examination of a MM-NT shows a large, expansile dermal nodule with irregular pigmentation  and areas of epidermal thinning and necrosis  (but no complete ulceration in this section). |
TERMINOLOGY
Abbreviations
Melanoma, nodular type (MM-NT)
Definitions
Invasive melanoma that histologically lacks a prominent junctional component (radial growth phase does not extend beyond 3 rete ridges of invasive vertical growth phase)
CLINICAL ISSUES
Epidemiology
Incidence
2nd most common subtype of invasive melanoma (after superficial spreading type)
Age
Median age of onset is 49 years
