Nodular Melanoma
A 74-year-old man presented for evaluation of a pigmented nodule on the left arm that had grown over 2 months’ time. A biopsy was performed, which revealed nodular melanoma.
Nodular melanoma describes a clinical presentation of melanoma devoid of a significant macular
(radial) component.1 Although older studies suggested histologic criteria such as limitation of the radial growth phase to less than three rete ridges,2 there has been no accepted standardized histologic approach to diagnosis. Clinical presentation remains the most important defining feature.
Nodular melanoma comprises approximately one tenth of all melanomas and is more commonly found in men.1 Recent reports have addressed differences in nodular melanoma from metastases and primary dermal melanoma.3 Nodular melanoma is increasing in incidence, along with all other types of melanoma.4 Most nodular melanomas do not exhibit the asymmetry, irregular border, variegated color, and diameter larger than 6.0 mm that have been successfully publicized as warning signs for superficial spreading malignant melanoma.5 Because nodular melanoma may be symmetrical and well-circumscribed and exhibit none of the ABCD features, an “E” has recently been added to alert patients to the dangers of a growing or erythematous, elevated, or evolving tumor.6 Any lesion suspected of being a melanoma should be biopsied.
Even with early detection, nodular melanomas can grow several millimeters over a few weeks’ time and may be associated with high mortality and poor outcome.7 Some studies have shown the surprising results that delay in detection may not be associated with a worse prognosis due to the rapid rate of growth and proclivity to metastasis of some melanomas.8
Therapy for metastatic melanoma is difficult. Although commonly performed, sentinel lymph node studies followed by lymphadenectomy when indicated are helpful in determining prognosis but have questionable benefits for overall survival.9,10 Interferon alpha therapy is of some utility.11 Early diagnosis followed by complete removal is still the best treatment.
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3. Cassarino DS, Cabral ES, Karthar V, Swetter SM. Primary dermal melanoma: Distinct immunohistochemical findings and clinical outcome com-pared with nodular and metastatic melanoma. Arch Dermatol. 2008;144:49-56.
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melanoma: perspective observational study. BMJ. 2006;332(7555):1423.
10. Wick MR, Patterson JW. Sentinel lymph node biopsies for cutaneous melanoma. [Review]. Am J Surg Pathol. 2005;29 (3):412-414.
11. Moschos S, Kirkwood JM. Present role and future potential of type I interferon in adjuvant therapy high-risk operable melanoma. Cytokine Growth Factor Rev. 2007;18 (5-6):451-458.