Cameo
Congenital Meianonychia Douglas E. Wong, M.D., Roger H. Brodkin, M.D., Robert R. Rickert, M.D., and S. G. McFalls, M.D.
• A 9-year-old white boy presented with a dark discoloration of the entire right index fingernail, present and gradually darkening since birth (Fig. 1). The entire nail plate was a gray-brown color. On closer examination streaks of deeper hyperpigmentation could be discerned. The proximal nail fold had a narrow margin of slateblue discoloration. The lateral nail folds and skin of the finger were uninvolved. A diagnosis of congenital nail matrix nevus was made. A longitudinal elliptical biopsy ofthe nail unit was performed, extending from the lunula into the proximal nail fold. It revealed increased numbers of solitary melanocytes at the dermoepidermal junction of the nail matrix (Fig. 2). Rare minute foci of aggregates of melanocytes into small nests were noted (Fig. 3). No atypia was present. Abundant melanin pigment was seen throughout all levels ofthe nail bed epithelium and nail plate. The overall histologic pattern was that of a simple lentigo. The occurrence of occasional small nests of melanocytes at the dermoepidermal junction suggests early transition to a junctional nevus.
of all congenital nevocytic nevi in contrast to lifelong Congenital nevocytic nevi of the nails have only rarely been reported.""'' In all cases concern about malignant change prompted excision. Prophylactic excision has been advocated for nevocytic nevi ofthe nails, especially those that have been congenital."* When subungual melanocytic lesions occur in whites, regardless of the histology, many authors suggest excision.^'^ In nonblacks, because of their rare occurrence, melanotic bands of the nails should be viewed as suspicious and should at least be biopsied.
Discussion While large congenital nevocytic nevi are generally believed to have an increased risk of malignant transformation, some authors remark that congenital nevi of any size appear to have an increased risk for developing malignant melanoma.' Although large lesions have been known to develop malignancy early in life, small congenital nevi rarely show malignant changes until puberty. Prior to puberty some would advise excision
From the Department of Dermatology, Mount Sinai Medical Center, Miami Beach, Rorida, the Departments of Medicine (Dermatology), and Pathology, New Jersey Medical School, Newark, New Jersey, the Department of Pathology, Saint Barnabas Medical Center, Livingston, New Jersey, and Jefferson Medical College, Philadelphia, Pennsylvania. Address correspondence to: Douglas E. Wong, M.D., 3301 NE 5th Avenue #914, Miami, FL 33137. .. ,-. ,,_ ., - '
278
Figure 1. Diffuse discoloration ofthe right index fingernail with involvement at the margin ofthe proximal nail fold.
April 1991, Vol. 30, No. 4
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Congenital Melanonychia • Wong et al.
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Figure 2. Nail matrix showing histologic pattern of a simple lentigo. Note numerous melanoeytes at the dermoepidermal junction and elongated rete ridges. Abundant melanin pigment is seen throughout the nail plate. , . _ • ,
It has been shown that the majority of subungual melanomas demonstrate prior pigmentation.^ Saida and Ohshima observed five cases of subungual malignant melanoma in Japanese patients in which the initial sign was melanonychia striata.'" Among the factors cited as suggestive of early subungual melanoma is a pigmented band greater than 6 mm in width, its onset after middle age, dystrophic changes ofthe nail, and a pigmented macule on the periungual skin (Hutchinson sign).'°
For those simple lentigines with evidence of early nest formation, Ackerman has playfully coined the term "jentigo,"'-' At what point these evolving lesions can be called a junctional nevus is uncertain. Stegmaier and Montgomery have reclassified simple lentigines as junctional nevi in the presence of a single nest of nevus cells.'" Although lacking substantial evidence, theory suggests that a simple lentigo may evolve into a junctional nevus and may become part of a process producing a compound or intradermal nevus.""'" Spontaneous involution later in hfe is the endpoint of these melanocytic nevi. Clark et al. describe a cycle of progression from a melanocytic nevus to a malignant melanoma which differs from the life cycle of these common acquired melanocytic nevi.'^ There is at present a great deal of controversy about: (1) the malignant potential of small congenital nevi; (2) the malignant potential of subungual nevi; and (3) the relationship of childhood lentigines to the evolution of nevi and to the development of melanomas. The case presented focuses on therapeutic considerations in a clinical situation where these controversies must be weighed.
References
Figure 3. Higher power view of lesion showing small nest of melanocytes at the dermoepidermal junction (arrow).
1. Rhodes AR, Sober AJ, Day CL, et al. The malignant potential of small congenital nevocellular nevi. J Am Acad Dermatol. 1982;6;230-241. 2. Arons MS, Hunvitz S. Congenital nevocellular nevus; A review of the treatment controversy and a report of 46 cases. Plast Reconstr Surg. 1983;72:355-365. 3. Mollitt DL, Golladay ES. Management of congenital nevocellular nevi. Am J Surg. 1985;150;669-671. 4. Coskey RJ, Magnell TD, Bernacki EG Jr. Congenital subungual nevus. J Am Acad Dermatol. 1983;9:747-751.
280
International Journal of Dermatology • April 1991
5. Ohtsuka HO, Hori Y, Ando M. Nevus ofthe little finger with a remarkable nail deformity. Plast Reconstr Surg. I978;61;1O8111. 6. Caron GA. Familial congenital pigmented nevi ofthe nails. Lancet. 1962; 1:508-509. 7. Kopf AW, Waldo E. Melanonychia striata. Australas J Dermatol. 1980;21;59-70. 8. Leyden JJ, Spott DA, Goldschmidt H. Diffuse and banded melanin pigmentation in nails. Arch Dermatol. 1972; 105:548-550. 9. Feibleman CE, Maize JC. Racial differences in cutaneous melanoma incidence and distribution. In: Ackerman AB, ed. Pathology of Malignant Melanoma. New York: Masson, I98I;47-58. 10. Saida T, Ohshima Y. Clinical and histopathologic characteristics
11. 12. 13. 14. 15.
of early lesions of subungual malignant melanoma. Cancer. 1989;63;556-560. Pinkus H, Mehregan AH. A Guide to Dermatohistopathology. 3rd ed. New York; Appleton-Century-Crofts, 1981;364-366. Maize JC, Foster G. Age related changes in melanocytic nevi. Clin Exp Dermatol. 1979;4;49-58. Maize JC, Ackennan AB. Pigmented Lesions ofthe Skin. Philadelphia; Lea & Febiger, 1987;82. Stegmaier DC, Montgomery H. Histopathologic studies of pigmented nevi in children. J Invest Dermatol. 1953;20;5I-62. Clark WH. The development and biological significance of neoplasia. The Lila Gruber Memorial Cancer Research Award Lecture, American Academy of Dermatology, 42nd Annual Meeting, Chicago, December 1984. .
Large religious motif on the back, not frequently seen today (courtesy of D. Van der Plueg, M.D.). From the World of Tattoos collection, Honolulu, HI. Submitted by Norman Goldstein, M.D., Honolulu, HI.
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Vol. 30
Congenital Meianonychia Douglas E. Wong, M.D., Roger H. Brodkin, M.D., Robert R. Rickert, M.D., and S. G. McFalls, M.D.
• A 9-year-old white boy presented with a dark discoloration of the entire right index fingernail, present and gradually darkening since birth (Fig. 1). The entire nail plate was a gray-brown color. On closer examination streaks of deeper hyperpigmentation could be discerned. The proximal nail fold had a narrow margin of slateblue discoloration. The lateral nail folds and skin of the finger were uninvolved. A diagnosis of congenital nail matrix nevus was made. A longitudinal elliptical biopsy ofthe nail unit was performed, extending from the lunula into the proximal nail fold. It revealed increased numbers of solitary melanocytes at the dermoepidermal junction of the nail matrix (Fig. 2). Rare minute foci of aggregates of melanocytes into small nests were noted (Fig. 3). No atypia was present. Abundant melanin pigment was seen throughout all levels ofthe nail bed epithelium and nail plate. The overall histologic pattern was that of a simple lentigo. The occurrence of occasional small nests of melanocytes at the dermoepidermal junction suggests early transition to a junctional nevus.
of all congenital nevocytic nevi in contrast to lifelong Congenital nevocytic nevi of the nails have only rarely been reported.""'' In all cases concern about malignant change prompted excision. Prophylactic excision has been advocated for nevocytic nevi ofthe nails, especially those that have been congenital."* When subungual melanocytic lesions occur in whites, regardless of the histology, many authors suggest excision.^'^ In nonblacks, because of their rare occurrence, melanotic bands of the nails should be viewed as suspicious and should at least be biopsied.
Discussion While large congenital nevocytic nevi are generally believed to have an increased risk of malignant transformation, some authors remark that congenital nevi of any size appear to have an increased risk for developing malignant melanoma.' Although large lesions have been known to develop malignancy early in life, small congenital nevi rarely show malignant changes until puberty. Prior to puberty some would advise excision
From the Department of Dermatology, Mount Sinai Medical Center, Miami Beach, Rorida, the Departments of Medicine (Dermatology), and Pathology, New Jersey Medical School, Newark, New Jersey, the Department of Pathology, Saint Barnabas Medical Center, Livingston, New Jersey, and Jefferson Medical College, Philadelphia, Pennsylvania. Address correspondence to: Douglas E. Wong, M.D., 3301 NE 5th Avenue #914, Miami, FL 33137. .. ,-. ,,_ ., - '
278
Figure 1. Diffuse discoloration ofthe right index fingernail with involvement at the margin ofthe proximal nail fold.
April 1991, Vol. 30, No. 4
Wo. 4
Congenital Melanonychia • Wong et al.
279
Figure 2. Nail matrix showing histologic pattern of a simple lentigo. Note numerous melanoeytes at the dermoepidermal junction and elongated rete ridges. Abundant melanin pigment is seen throughout the nail plate. , . _ • ,
It has been shown that the majority of subungual melanomas demonstrate prior pigmentation.^ Saida and Ohshima observed five cases of subungual malignant melanoma in Japanese patients in which the initial sign was melanonychia striata.'" Among the factors cited as suggestive of early subungual melanoma is a pigmented band greater than 6 mm in width, its onset after middle age, dystrophic changes ofthe nail, and a pigmented macule on the periungual skin (Hutchinson sign).'°
For those simple lentigines with evidence of early nest formation, Ackerman has playfully coined the term "jentigo,"'-' At what point these evolving lesions can be called a junctional nevus is uncertain. Stegmaier and Montgomery have reclassified simple lentigines as junctional nevi in the presence of a single nest of nevus cells.'" Although lacking substantial evidence, theory suggests that a simple lentigo may evolve into a junctional nevus and may become part of a process producing a compound or intradermal nevus.""'" Spontaneous involution later in hfe is the endpoint of these melanocytic nevi. Clark et al. describe a cycle of progression from a melanocytic nevus to a malignant melanoma which differs from the life cycle of these common acquired melanocytic nevi.'^ There is at present a great deal of controversy about: (1) the malignant potential of small congenital nevi; (2) the malignant potential of subungual nevi; and (3) the relationship of childhood lentigines to the evolution of nevi and to the development of melanomas. The case presented focuses on therapeutic considerations in a clinical situation where these controversies must be weighed.
References
Figure 3. Higher power view of lesion showing small nest of melanocytes at the dermoepidermal junction (arrow).
1. Rhodes AR, Sober AJ, Day CL, et al. The malignant potential of small congenital nevocellular nevi. J Am Acad Dermatol. 1982;6;230-241. 2. Arons MS, Hunvitz S. Congenital nevocellular nevus; A review of the treatment controversy and a report of 46 cases. Plast Reconstr Surg. 1983;72:355-365. 3. Mollitt DL, Golladay ES. Management of congenital nevocellular nevi. Am J Surg. 1985;150;669-671. 4. Coskey RJ, Magnell TD, Bernacki EG Jr. Congenital subungual nevus. J Am Acad Dermatol. 1983;9:747-751.
280
International Journal of Dermatology • April 1991
5. Ohtsuka HO, Hori Y, Ando M. Nevus ofthe little finger with a remarkable nail deformity. Plast Reconstr Surg. I978;61;1O8111. 6. Caron GA. Familial congenital pigmented nevi ofthe nails. Lancet. 1962; 1:508-509. 7. Kopf AW, Waldo E. Melanonychia striata. Australas J Dermatol. 1980;21;59-70. 8. Leyden JJ, Spott DA, Goldschmidt H. Diffuse and banded melanin pigmentation in nails. Arch Dermatol. 1972; 105:548-550. 9. Feibleman CE, Maize JC. Racial differences in cutaneous melanoma incidence and distribution. In: Ackerman AB, ed. Pathology of Malignant Melanoma. New York: Masson, I98I;47-58. 10. Saida T, Ohshima Y. Clinical and histopathologic characteristics
11. 12. 13. 14. 15.
of early lesions of subungual malignant melanoma. Cancer. 1989;63;556-560. Pinkus H, Mehregan AH. A Guide to Dermatohistopathology. 3rd ed. New York; Appleton-Century-Crofts, 1981;364-366. Maize JC, Foster G. Age related changes in melanocytic nevi. Clin Exp Dermatol. 1979;4;49-58. Maize JC, Ackennan AB. Pigmented Lesions ofthe Skin. Philadelphia; Lea & Febiger, 1987;82. Stegmaier DC, Montgomery H. Histopathologic studies of pigmented nevi in children. J Invest Dermatol. 1953;20;5I-62. Clark WH. The development and biological significance of neoplasia. The Lila Gruber Memorial Cancer Research Award Lecture, American Academy of Dermatology, 42nd Annual Meeting, Chicago, December 1984. .
Large religious motif on the back, not frequently seen today (courtesy of D. Van der Plueg, M.D.). From the World of Tattoos collection, Honolulu, HI. Submitted by Norman Goldstein, M.D., Honolulu, HI.
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Vol. 30
