Summary
In congenital naevocytic naevi (CNN), the ultrastructure of melanosomes has been demonstrated only in a few case reports. In the present study, five defined skin levels were systematically compared by electron microscopy in five giant and seven medium-sized CNN. The ages of the patients ranged from 5 days to 29 years. Six common acquired naevocytic naevi (ANN) served as controls. Melanosomes were classified morphologically into several groups. Epidermal melanosomes were normal in all cases. In 10 of the 12 patients, the morphology and size of dermal melanosomes corresponded well with those in ANN, although in four young children (up to 4-years-old) a few enlarged or atypical forms were found. On the other hand, two new-born babies showed rather different, grossly enlarged dermal melanosomes of various shapes and some unusual internal features. They were seen focally even in lower dermal layers and in naevus cells in subepidermal sweat ducts. We conclude that dermal naevus cells in CNN of new-borns, at least in some cases, may contain melanosomes with unusual morphological variations. This does not necessarily indicate malignant transformation.
Similar content being viewed by others
References
Ainsworth AM, Folberg R, Reed RJ, Clark WH Jr (1979) Melanocytic nevi, melanocytomas, melanocytic dysplasias, and uncommon forms of melanoma. In: Clark WH Jr, Goldman LI, Mastrangelo MJ (eds) Human malignant melanoma. Clinical oncology monographs. Grune & Stratton, New York San Francisco London, pp 167–208
Curran RC, McCann BG (1976) The ultrastructure of benign pigmented naevi and melanocarcinomas in man. J Pathol 119:135–146
Drzewiecki KT (1979) Cutaneous malignant melanoma. Scand J Plast Reconstr Surg 13:321–332
Ghadially FN (1985) Is it a melanoma? In: Diagnostic electron microscopy of tumors, 2nd edn. Butterworths, London, pp 106–122
Ghadially FN, Ghadially R, Lalonde J-MA (1986) A comparative ultrastructural study of cutaneous blue naevi of humans and hamsters. J Submicrosc Cytol 18:417–432
Hashimoto K (1971) The ultrastructure of the skin of human embryos. VIII. Melanoblast and intrafollicular melanocyte. J Anat 108:99–108
Hashimoto K, Bale GF (1972) An electron microscopic study of balloon cell nevus. Cancer 30:530–540
Hönigsmann H, Wolff K, Konrad K (1974) Systemische Naevomatose: Tierfellnaevus, multiple eruptive Naevi und Naevuszellabsiedelungen in den Lymphknoten. Hautarzt 25:547–553
Hori Y, Nakayama J, Okamoto M, Nagae S, Taniguchi S, Takayama O, Oohara K (1989) Giant congenital nevus and malignant melanoma. J Invest Dermatol 92:310S-314S
Hunter JAA, Zaynoun S, Paterson WD, Bleehen SS, Mackie R, Cochran AJ (1978) Cellular fine structure in the invasive nodules of different histogenetic types of malignant melanoma. Br J Dermatol 98:255–272
Illig L, Weidner F, Hundeiker M, Gartmann H, Biess B, Leyh F, Paul E (1985) Congenital nevi<10 cm as precursors to melanoma. 52 cases, a review, and a new conception. Arch Dermatol 121:1274–1281
Jimbow K, Oikawa O, Sugiyama S, Takeuchi T (1979) Comparison of eumelanogenesis and pheomelanogenesis in retinal and follicular melanocytes; role of vesiculo-globular bodies in melanosome differentiation. J Invest Dermatol 73:278–284
Kerl H, Smolle J, Hödl St, Soyer HP (1989) Kongenitales Pseudomelanom. Z Hautkr 64:564–568
Konrad K, Hönigsmann H, Wolff K (1972) Bindegewebsmelanocyten beim Menschen. Elektronenmikroskopische und histochemische Untersuchungen beim Mongolenfleck und blauen Naevus. Arch Dermatol Forsch 244:273–275
Kopf AW, Bart RS, Hennessey P (1979) Congenital nevocytic nevi and malignant melanomas. J Am Acad Dermatol 1:123–130
Kuehnl-Petzoldt C, Kunze J, Mueller R, Volk B, Petres J (1984) Histology of congenital nevi during the first year of life. A study by conventional and electron microscopy. Am J Dermatopathol 6 [Suppl 1]:81–88
Langer K, Rappersberger K, Steiner A, Konrad K, Wolff K (1990) The ultrastructure of dysplastic naevi: comparison with superficial spreading melanoma and common naevocellular naevi. Arch Dermatol Res 282:353–362
Maie O, Schneider BV (1986) The ultrastructure of congenital nevocytic nevi. II. Nevus cell morphology and contacts with nerve fibers. Arch Dermatol Res 278:398–406
Margo CE, Habal MB (1987) Large congenital melanocytic nevus. Light and electron microscopic findings. Ophthalmology 94:960–965
Mark GJ, Mihm MC, Liteplo MG, Reed RJ, Clark WH (1973) Congenital melanocytic nevi of the small and garment type. Clinical, histologic, and ultrastructural studies. Hum Pathol 4:395–418
Maul GG, Romsdahl MM (1970) Ultrastructural comparison of two human malignant melanoma cell lines. Cancer Res 30:2782–2790
Mishima Y (1967) Melanotic tumors. In: Zelickson AS (ed) Ultrastructure of normal and abnormal skin. Lea & Febiger, Philadelphia, pp 388–424
Nakagawa H, Rhodes AR, Fitzpatrick TB, Hori Y (1984) Acid phosphatase in melanosome formation: a cytochemical study in normal human melanocytes. J Invest Dermatol 83:140–144
Nordlund JJ (1986) The lives of pigment cells. Dermatol Clin 4:407–419
Rhodes AR, Seki Y, Fitzpatrick TB, Stern RS (1988) Melanosomal alterations in dysplastic melanocytic nevi. A quantitative, ultrastructural investigation. Cancer 61:358–369
Schneider BV, Maie O (1985) The ultrastructure of congenital nevocytic nevi. I. Nevus cells in walls of blood vessels and lymphatics. Arch Dermatol Res 278:49–56
Schnyder UW, Schneider BV, Maie O, Groh V, Sigg Ch (1987) Kongenitale Naevuszellnaevi als Melanompraekursoren der Haut. Monatsschr Kinderheilkd 135:259–264
Schreiner E, Wolff K (1970) Die Ultrastruktur des benignen juvenilen Melanoms. Arch Klin Exp Dermatol 237:749–768
Silvers DN, Helwig EB (1981) Melanocytic nevi in neonates. J Am Acad Dermatol 4:166–175
Szekeres L (1975) Fine structure and X-ray microanalysis of melanosomes in pigmented nevi and melanomas. Arch Dermatol Forsch 252:297–304
Takahashi H, Horikoshi T, Jimbow K (1985) Fine structural characterization of melanosomes in dysplastic nevi. Cancer 56:111–123
Yu H-S, Tsaur K-C, Chien C-H, Perng J-J, Lu C-C (1985) Neurocutaneous melanosis: electron microscopic comparison of the pigmented melanocytic nevi of skin and meningeal melanosis. J Dermatol 12:267–276
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Schneider, B.V., Schnyder, U.W. The ultrastructure of congenital naevocytic naevi. Arch Dermatol Res 283, 438–444 (1991). https://doi.org/10.1007/BF00371779
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00371779