Journal of Cutaneous Pathology 1979: 6: 53-58
The Dermal Component in Melanosis Naeviformis Becker
E. HANEKE Department of Dermatology, University of Erlangen, Erlangen, Germany Histological investigations were performed in 11 subjects suffering from melanosis naeviformis Becker. Apart from the well-known epidermal alterations such as basal hyperpigmentation, slight acanthosis and growth of coarse hair, dermal elianges were found in each case. The dermis was considerably thickened and contained numerous small and/or large bundles of smooth muscle without relation to cutaneous adnexa. Thus, melanosis naeviformis Becker can be considered an organoid nevus with epidermal, melanocytic and dermal components. (Received for publication July 3, 1978)
Melanosis naeviformis Becker (MNB) (Becker 1949) is a fairly common but rarely noted and often overlooked or misdiagnosed lesion. It is characterized by a uniformly fair to dark brown patch of at least palm-size, the border of wliich is sharply outlined but highly irregular and resolving into small patches Uke an archipelago (Becker 1949, Frain-Bell & Rook 1957, Copeman & Jones 1965, Gartmann et al. 1968). The growth of eoarse hair is not found in all cases (Gartmann et al. 1 968) but is characteristic of the unique clinieal picture if present. MNB often develops after intense exposure to sunlight. It has been classified both as a pigmented hairy epidermal nevus (Frain-Bell & Rook 1957, Copeman & Jones 1965) and an organie hamartoma with differentiation of mature hair structures (Lever 1967). Nevus cells have never been found (Kopf & Yuppa 1968). tVlaterJals and Methods
Patients MNB was diagnosed in 17 patients, but only 11 of them consulted because of the slowly growing pigmentation (Fig. 1).
Histopathology Incisional biopsy was permitted in 11 cases. Paraffin sections were stained with hematoxylin & eosin, van Gieson, Fontana's argentaffin reaction and cresyl violet. Results
The epidermis showed a slight acanthosis with numerous tender, sometimes anastomosing rete pegs. Mild hyperkeratosis was found in tliree cases only. The cells of the basal and suprabasal layers were heavily pigmented. Melanin granules were arranged above the nucleus of basal cells in the form of a pole cap. The nielanocytes were only slightly increased, if at all. The papiUary body and sometimes the upper dermis contained melanophages (Fig. 2). The dermis was significantly thickened as compared with normal skin of symmetric contralateral sites. Besides single hair follicles, numerous smaU and thick bundles of smooth muscle fibers without relation to foUicles or blood vessels eould be observed (Figs. 3 and 4). They were irregularly arranged and sometimes contained only very few muscle ceUs so that they could easily
0303/6987/79/010053-06 $02.50/0 © 1979 Munksgaaid, Copenhagen
HANEKE
54
Fig. I. Melanosis naeviformis Becker on the left shoulder.
escape notice. Though the number and/or size of these smooth muscle bundles was so striking as to be already eonspieuous in seven H & E stained sections they were markedly augmented in aU van Gieson specimens. There was no significant correlation between the duration of MNB, hair growth and number of smooth muscles. Mast ceUs were frequent in subepidermal and perifolUcular arrangement. A particular relation to cutaneous nerves could not be found. Discussion
The commonly described histological feat-
ures of MNB are slight acanthosis with tender rete pegs, occasional hyperkeratosis, marked hyperpigmentation of the basal layers and varying amount of melanophages mainly in the papillary body. The number of basal melanocytes is only sUghtly increased. The hair foUicles are normal (Lever & Schaumburg-Lever 1975). Electron microscopically, the hyperpigmentation is similar to that found after exposure to sunUght with markedly increased activity of the melanocytes and complexing of melanosomes, indicating an augmented melanin synthesis (Frenk & Delaeretaz 1970, Gebhart et al. 1971), although the number of melanocytes is almost normal. Gebhart et al. (1971)
DERMIS IN MELANOSIS BECKER
55
Fig. 2. Melanosis naeviformis Becker. Heavily pigmented basal layer and mdanophages in the papillary b o d y ; Fontana's argentaffin reaction, magnification: X 250.
found a particular relation of mast cells to cutaneous nerves and blood vessels with electron microscopy. Staining with metachromatic dyes, however, did not reveal in o u r material an abnormal number of either peri- or intraneural mast cells. Up to now, the study of dermal alterations in MNB has mostly been neglected, although Stokes, in his publication (1923) concerning a 'nevus pilaris with hyperplasia of nonstriated muscle', was probably the first to describe what we now call MNB. Urbanek & Johnson (1978), however, believe it to be the association of MNB with a
smooth muscle hamartoma. The present study showed that a smooth muscle hyperplasia of varying degree can be found in practically all cases. Furthermore, the thickening of the dermis is striking. A dermal component in MNB seems to have also been suggested by other authors (Goedbloed 1954, Spira & Griem 1967, Copeman & Jones 1965 (two cases)). An increase in smooth muscle fibers was observed in chronic lymphedema of the leg (Cluzan & Levillain 1976) and rarely beneath seborrheic keratoses (unpublished observations). The origin of the smooth tnuscles in MNB
56
HANEKE
\, Figs. 3 and 4. The dermis in MNB contains masses of small and large bundles of smooth muscle cells; van Gieson, magnification: 3: X 20, 4: X 80.
is still unknown. It may either be a congenital hypertrophic anlage of the musculi cutis diagonales (Schiefferdecker 1917) or the development from pluripotent fibroblasts, as can be suggested in the case of lymphedema. However, only in very pronounced cases does the smooth musculature of MNB resemble the so-called muscle plate (Pinkus 1927). Svindland & Wetterland (1975) found granulomatous infUtrates around hair follicles in the margin of MNB containing epithelioid and giant cells. Since the MNB in their case developed 6 months after a BCG
vaccination they considered an atypical mycobacterial infection as the cause of the MNB. Out of our 11 cases, a granulomatous infiltrate with some epitheUoid cells was found in only one case. It could as well be an inflammatory reaction to a damaged follicle. Since the dermal changes, though to various degrees, were found in all cases we feel that the hyperplasia of smooth muscles and the thickening of the dermis are part of MNB and a feature which contributes to the histological diagnosis. Thus it does not represent an association of MNB with smooth muscle hamartoma, but another constituent
DERMIS IN MELANOSIS BECKER
57
•/• 1' Fig. 4. hairy epidermal nevus (Becker). Archives of Derttiatology 92, 249-251. Frain-Bell, W. & Rook, A. (1957) Pigmented and hypertrichotic epidermal nevus. Transactions of the St. John's Hospital dermatological Society (Lotidon) 39, 51-55. References Frenk, E. & Delaeretaz, J. (1970) Zur Ultrastruktur der Beeker'schen Melanose. Hautarzt 21, 397-400. Becker, S. W. (1949) Concurrent melanosis and hypertrichosis in distribution of nevus unius Gartmann, H., Neuhaus, D. & Tritsch, F. (1968) Melanosis naeviformis. Zeitschrift fiir Haut- und lateris. Archives of Dermatology and SyphiloGeschlechtskrankheiten 43, 973-984. logy 60,155-160, Cluzan, R. & Levillain, R. (1976) L'hyperplasie Gebhart, W., Kidd, R. L. & Niebauer, G. (1971) Beckersche Melanose. Archiv fiir derntatolomusculaire lisse dans les lymphoedernes. In gische Forscltung 241, 166-178. Ergebtiisse der Angiologie, vol. 13: Basic LymR. (1954) Naevus vaseulosophology, ed. Foldi, M., pp. 71-76. Stuttgart, Goedbloed, pigmentoso-pilosus tardus. Dermatologiea 109 New York: Schattauer. 231. Copeman, P. W, & Jones, E. W. (1965) Pigmented
of a tardive organoid nevus or hamartoma with epidermal, melanocytic and dermal components.
58
HANEKE
nevus unius lateris (Becker) with eczemaKopf, A. W. & Yuppa, J. (1968) Becker's nevus. tization? Archives of Dermatology 97, 540Archives of Dermatology 98, 97-98. 541. Lever, W. F. (1967) Histopathology of the Skin, 4th edn., pp. 534-537, London: Pitman Medi- Stokes, J. H. (1923) Nevus pilaris with hyperplasia of nonstriated muscle. Archives of Dermatology cal Publishers - Philadelphia: Lippincott. and Syphilology 7, 479-481. Lever, W. F. & Schaumburg-Lever, G. (1975) Histopathology of the Skin, 5th edn., p. 659, Svindland, H. B. & Wetterland, P. (1975) A case of pigmentary hair naevus (Beeker). Acta dermatoPliiladelphia-Toronto: Lippincott. venereologica (Stockholtn) 55, 141-145. Pinkus, F. (1927) Die normalc Anatomie der Haut: Die glatte Muskulatur der Haut. In:/. Jadassohn Urbanek, R. W. & Johnson, W. C (1978) Smooth Handbuch der Haut und Gesehleehtskrankmuscle hamartoma associated with Becker's heiten I/I, pp. 256-266. BerUn, Springernevus. Archives of Dermatology 114, 104Verlag. 106. Pinkus, H. (1965) Zur Begriffsbestimmung der Naevi, Organnaevi und naevoiden Tumoren. Hautarzt 16, 184-190. Schiefferdecker, P. (1917) cit. Schmidt, W. (1968) Die normale Histologie von Corium und Sub- Address: cutis. Die Muskulatur der Haut. In J. Jadas- Dr. E. Haneke sohn Handbuch der Haut- und Gesehleehts- Dermatologische Universitatsklinik krankheiten I/I, pp. 479^82. Berlin, Heidel- (Head: Prof Dr. O. P. Hornstcin) Erlangen, Hartmannstr. 14 berg, New York: Springer-Verlag. Spira, A. & Griem, S. F. (1967) Concurrent D-8520 Erlangen West Germany melanosis and hypertrichosis in distribution of
The Dermal Component in Melanosis Naeviformis Becker
E. HANEKE Department of Dermatology, University of Erlangen, Erlangen, Germany Histological investigations were performed in 11 subjects suffering from melanosis naeviformis Becker. Apart from the well-known epidermal alterations such as basal hyperpigmentation, slight acanthosis and growth of coarse hair, dermal elianges were found in each case. The dermis was considerably thickened and contained numerous small and/or large bundles of smooth muscle without relation to cutaneous adnexa. Thus, melanosis naeviformis Becker can be considered an organoid nevus with epidermal, melanocytic and dermal components. (Received for publication July 3, 1978)
Melanosis naeviformis Becker (MNB) (Becker 1949) is a fairly common but rarely noted and often overlooked or misdiagnosed lesion. It is characterized by a uniformly fair to dark brown patch of at least palm-size, the border of wliich is sharply outlined but highly irregular and resolving into small patches Uke an archipelago (Becker 1949, Frain-Bell & Rook 1957, Copeman & Jones 1965, Gartmann et al. 1968). The growth of eoarse hair is not found in all cases (Gartmann et al. 1 968) but is characteristic of the unique clinieal picture if present. MNB often develops after intense exposure to sunlight. It has been classified both as a pigmented hairy epidermal nevus (Frain-Bell & Rook 1957, Copeman & Jones 1965) and an organie hamartoma with differentiation of mature hair structures (Lever 1967). Nevus cells have never been found (Kopf & Yuppa 1968). tVlaterJals and Methods
Patients MNB was diagnosed in 17 patients, but only 11 of them consulted because of the slowly growing pigmentation (Fig. 1).
Histopathology Incisional biopsy was permitted in 11 cases. Paraffin sections were stained with hematoxylin & eosin, van Gieson, Fontana's argentaffin reaction and cresyl violet. Results
The epidermis showed a slight acanthosis with numerous tender, sometimes anastomosing rete pegs. Mild hyperkeratosis was found in tliree cases only. The cells of the basal and suprabasal layers were heavily pigmented. Melanin granules were arranged above the nucleus of basal cells in the form of a pole cap. The nielanocytes were only slightly increased, if at all. The papiUary body and sometimes the upper dermis contained melanophages (Fig. 2). The dermis was significantly thickened as compared with normal skin of symmetric contralateral sites. Besides single hair follicles, numerous smaU and thick bundles of smooth muscle fibers without relation to foUicles or blood vessels eould be observed (Figs. 3 and 4). They were irregularly arranged and sometimes contained only very few muscle ceUs so that they could easily
0303/6987/79/010053-06 $02.50/0 © 1979 Munksgaaid, Copenhagen
HANEKE
54
Fig. I. Melanosis naeviformis Becker on the left shoulder.
escape notice. Though the number and/or size of these smooth muscle bundles was so striking as to be already eonspieuous in seven H & E stained sections they were markedly augmented in aU van Gieson specimens. There was no significant correlation between the duration of MNB, hair growth and number of smooth muscles. Mast ceUs were frequent in subepidermal and perifolUcular arrangement. A particular relation to cutaneous nerves could not be found. Discussion
The commonly described histological feat-
ures of MNB are slight acanthosis with tender rete pegs, occasional hyperkeratosis, marked hyperpigmentation of the basal layers and varying amount of melanophages mainly in the papillary body. The number of basal melanocytes is only sUghtly increased. The hair foUicles are normal (Lever & Schaumburg-Lever 1975). Electron microscopically, the hyperpigmentation is similar to that found after exposure to sunUght with markedly increased activity of the melanocytes and complexing of melanosomes, indicating an augmented melanin synthesis (Frenk & Delaeretaz 1970, Gebhart et al. 1971), although the number of melanocytes is almost normal. Gebhart et al. (1971)
DERMIS IN MELANOSIS BECKER
55
Fig. 2. Melanosis naeviformis Becker. Heavily pigmented basal layer and mdanophages in the papillary b o d y ; Fontana's argentaffin reaction, magnification: X 250.
found a particular relation of mast cells to cutaneous nerves and blood vessels with electron microscopy. Staining with metachromatic dyes, however, did not reveal in o u r material an abnormal number of either peri- or intraneural mast cells. Up to now, the study of dermal alterations in MNB has mostly been neglected, although Stokes, in his publication (1923) concerning a 'nevus pilaris with hyperplasia of nonstriated muscle', was probably the first to describe what we now call MNB. Urbanek & Johnson (1978), however, believe it to be the association of MNB with a
smooth muscle hamartoma. The present study showed that a smooth muscle hyperplasia of varying degree can be found in practically all cases. Furthermore, the thickening of the dermis is striking. A dermal component in MNB seems to have also been suggested by other authors (Goedbloed 1954, Spira & Griem 1967, Copeman & Jones 1965 (two cases)). An increase in smooth muscle fibers was observed in chronic lymphedema of the leg (Cluzan & Levillain 1976) and rarely beneath seborrheic keratoses (unpublished observations). The origin of the smooth tnuscles in MNB
56
HANEKE
\, Figs. 3 and 4. The dermis in MNB contains masses of small and large bundles of smooth muscle cells; van Gieson, magnification: 3: X 20, 4: X 80.
is still unknown. It may either be a congenital hypertrophic anlage of the musculi cutis diagonales (Schiefferdecker 1917) or the development from pluripotent fibroblasts, as can be suggested in the case of lymphedema. However, only in very pronounced cases does the smooth musculature of MNB resemble the so-called muscle plate (Pinkus 1927). Svindland & Wetterland (1975) found granulomatous infUtrates around hair follicles in the margin of MNB containing epithelioid and giant cells. Since the MNB in their case developed 6 months after a BCG
vaccination they considered an atypical mycobacterial infection as the cause of the MNB. Out of our 11 cases, a granulomatous infiltrate with some epitheUoid cells was found in only one case. It could as well be an inflammatory reaction to a damaged follicle. Since the dermal changes, though to various degrees, were found in all cases we feel that the hyperplasia of smooth muscles and the thickening of the dermis are part of MNB and a feature which contributes to the histological diagnosis. Thus it does not represent an association of MNB with smooth muscle hamartoma, but another constituent
DERMIS IN MELANOSIS BECKER
57
•/• 1' Fig. 4. hairy epidermal nevus (Becker). Archives of Derttiatology 92, 249-251. Frain-Bell, W. & Rook, A. (1957) Pigmented and hypertrichotic epidermal nevus. Transactions of the St. John's Hospital dermatological Society (Lotidon) 39, 51-55. References Frenk, E. & Delaeretaz, J. (1970) Zur Ultrastruktur der Beeker'schen Melanose. Hautarzt 21, 397-400. Becker, S. W. (1949) Concurrent melanosis and hypertrichosis in distribution of nevus unius Gartmann, H., Neuhaus, D. & Tritsch, F. (1968) Melanosis naeviformis. Zeitschrift fiir Haut- und lateris. Archives of Dermatology and SyphiloGeschlechtskrankheiten 43, 973-984. logy 60,155-160, Cluzan, R. & Levillain, R. (1976) L'hyperplasie Gebhart, W., Kidd, R. L. & Niebauer, G. (1971) Beckersche Melanose. Archiv fiir derntatolomusculaire lisse dans les lymphoedernes. In gische Forscltung 241, 166-178. Ergebtiisse der Angiologie, vol. 13: Basic LymR. (1954) Naevus vaseulosophology, ed. Foldi, M., pp. 71-76. Stuttgart, Goedbloed, pigmentoso-pilosus tardus. Dermatologiea 109 New York: Schattauer. 231. Copeman, P. W, & Jones, E. W. (1965) Pigmented
of a tardive organoid nevus or hamartoma with epidermal, melanocytic and dermal components.
58
HANEKE
nevus unius lateris (Becker) with eczemaKopf, A. W. & Yuppa, J. (1968) Becker's nevus. tization? Archives of Dermatology 97, 540Archives of Dermatology 98, 97-98. 541. Lever, W. F. (1967) Histopathology of the Skin, 4th edn., pp. 534-537, London: Pitman Medi- Stokes, J. H. (1923) Nevus pilaris with hyperplasia of nonstriated muscle. Archives of Dermatology cal Publishers - Philadelphia: Lippincott. and Syphilology 7, 479-481. Lever, W. F. & Schaumburg-Lever, G. (1975) Histopathology of the Skin, 5th edn., p. 659, Svindland, H. B. & Wetterland, P. (1975) A case of pigmentary hair naevus (Beeker). Acta dermatoPliiladelphia-Toronto: Lippincott. venereologica (Stockholtn) 55, 141-145. Pinkus, F. (1927) Die normalc Anatomie der Haut: Die glatte Muskulatur der Haut. In:/. Jadassohn Urbanek, R. W. & Johnson, W. C (1978) Smooth Handbuch der Haut und Gesehleehtskrankmuscle hamartoma associated with Becker's heiten I/I, pp. 256-266. BerUn, Springernevus. Archives of Dermatology 114, 104Verlag. 106. Pinkus, H. (1965) Zur Begriffsbestimmung der Naevi, Organnaevi und naevoiden Tumoren. Hautarzt 16, 184-190. Schiefferdecker, P. (1917) cit. Schmidt, W. (1968) Die normale Histologie von Corium und Sub- Address: cutis. Die Muskulatur der Haut. In J. Jadas- Dr. E. Haneke sohn Handbuch der Haut- und Gesehleehts- Dermatologische Universitatsklinik krankheiten I/I, pp. 479^82. Berlin, Heidel- (Head: Prof Dr. O. P. Hornstcin) Erlangen, Hartmannstr. 14 berg, New York: Springer-Verlag. Spira, A. & Griem, S. F. (1967) Concurrent D-8520 Erlangen West Germany melanosis and hypertrichosis in distribution of
