Journal of Cutaneous Pathology 1975: 2: 30-34
Lichen Sclerosus et Atrophicus An Electron Microscopic Study A. KrNT AND M. L. GEErvrs
•,,
Department of Dermatology, University of Ghent, Belgium The ultrastruetural cbanges in seven cases of lichen sclerosus et atrophicus arc described. An interesting epidermal alteration was the presence of collagen fibrils in the intercelKiUu' space; furtbermore, the basal cells were altered by condensation and homogcnization of the tonofibrils. The basctncnt membrane was not uniform and often multilayered. The anchoring fibrils were numerous. In the cutis intertwining strands of fine filaments, bundles of immature collagen and normal collagen could be found. In lichen sclerosus et atrophicus the dermo-epiderrnal interrelationship is disturbed. (Received for publication Novend>er 27, 1974)
Lichen sclerosus et atrophicus is character'ized histologically by tbe presence of an amorphous and cellular band underneath the epidermis (Montgomery & Hill 1940, Hauser 1958, Steigleder & Raab 1961, Suurmond 1964, Montgomery 1967, Hadida et al, 1970), The electron tnicroscopic studies of the subepidermal homogeneous zone reveal the presence of immature collagen fibrils and of bundles of closely packed but thin fibers showing a regular periodicity (Forssmann et al. 1964, Nicolau & Balus 1966, Hadida et al. 1970, Klug & Sonnichsen 1972, Mann & Cowan 1973). The subepidermal basement membrane is often broadened, and according to Klug & Sonnichsen (1972) the basal epidermal cells may show dyskeratotic signs and acantholysis. Mann & Cowan (1973) described clumps of collagen and elastin passing through the basement membrane and penetrating into the epidermis. It thus appears that in lichen sclerosus et atrophicus a distinct dermo-
epiderrnal interrelation does exist. This phenomenon brought us to an electron microscopic study of seven cases of lichen sclerosus et atrophicus. Material and Methods
Seven cases of lichen sclerosus et atrophicus were studied: two were localized on the back, two on the vulva and three on the preputium. The clinical diagnosis was confirmed in all of the cases by histologic examination. The biopsy specimens were fixed in 2.5 % glutaraldehyde buffer'ed with 0.1 M Sorensen's buffer and postfixed in buffered 1 % Os04. The tissues were embedded in Durcupan ACM, Ultrathin sections were cut with a Reichert ultrarnicrotome and double stained with lead citr'ate and Uranyl-acetate (Reynolds 1963). They were examined with Siemens Elmiskop I at 80 KV.
LICHEN SCLEROSUS ET ATROPHICUS
31
Fig. 1. A.F.: Anchoring fibrils; C : Immatur'e and matur'e collagen fibrils; EC: Epidermal cell; T: tonofilaments; | : cleft formed between the basal cell and the basement membrane. X 14,000.
Results
Epidermis Tbe membrane of the basal cells which lies directly above the basement membrane sometimes showed rectilinear structure, but more often pseudopodes intruding into the papillary layer were seen (Fig. 1). These pseudopodes were delineated by an utidulating tnembrane having numerous half desmosomes (Fig, 3). Some of the pseudopodes enclosed bundles of collagen fibrils, which were not always separated from the cell by a basement membrane. On the lateral and upper cell walls many cytoplasmic processes and microvilli were observed. The cytoplasm of the basal cells was dense and contained numerous mitochondria, ribo-
somes, glycogen, a rudimentary rough-sur'faced endoplasmic reticulum, tonofilaments and tubular structures measuring 150-180 A in diameter. In some cells the tonofibrils were grouped in bundles, which were often homogenized as could be seen in dysker'atotic cells. The nucleoplasm was granular and surrounded by a smooth nuclear membrane. The intercellular spaces were widened in the deep layers of the epidermis. Sometimes in these spaces fibrils measuring 400-500 A and showing tbe characteristic striation of collagen could be observed (Fig. 2). No basement membrane separated the fibrils frotn the surrounding cells. Between the epidermal cells many lymphocytes and
KINT AND GEERTS
Fig. 2. C: collagen in the intercellular spaces of the epidermis; MC: malpighian cell; N: nucleus; T: tonofilaments. X 20,300.
some unidentified mononuclear cells witb clear cytoplasm were present. The melanocytes generally had very few melanin granules and in most of the cases typical Langerhans cells could also be observed. In the more superficial layers of the epidermis the cell structure was very similar to that of normal skin. Dertnis The basement membrane was generally separated from the epidermis by a clear zone of 300 A; in some places, however, the space between the basal cells and the underlying basement membrane is broadened and clefts are formed (Fig, 1). Sometimes immature collagen fibrils could be seen between the membrane and the basal epider-
mal cell. The basement membrane itself was not uniform and varied in tbickness from 300 A to 900 A. It was often multilayered. In some areas it was lacking. Underneath the basement membrane the papillary layer and the superficial dermis were often oedematous, but they were also very dense and contained various fibrils, viz. (Fig. 3): a. anchoring fibrils normal in appear'ence. b. intertwining strands of fine filatnents of 60 A. c. bundles of irntnature collagen fibers havitig diameters varying from 400 to 800 A and showing a periodicity of 450-550 A. d. normal collagen bundles.
LICHEN SCLEROSUS ET ATROPHICUS
33
Fi.i,'. 3. A.F.: Anchoring fibrils; BM: Basement mer-nbranc; C: Mature and immature collagen fibrils; EC: epidermal cell; f: fine fibr-ils (60 A). X 42,000.
Tbe elastin fibers were rare. Tber-e were only a few fibroblasls. Their form was irregular and tbeir cytoplasm dense and filled up with thin filaments, which could leave the cell and accur-nulate in tbe extracellular space. In some of the fibroblasts lar-ge lacunes could be seen, eontaining striated collagen fiber-s. The capillaries and their pericytes appeared normal. Discussion
Tbe electron microscopic appearance of the superficial dermis in lichen sclerosus ct atrophicus is similar to scleroderma. In both diseases the structure of tbe cutis is dense and composed of protocollagcn and collagen fibrils of various dimensions. Tbe
oedematous appearance of tbe papillary layer in some sections was only visible in the early stage of the disease. It can be cor-npared with tbe bistologic findings, whicb in early lesions show oedematous zones underneath the epidermis. As the disease progr-esses, the superficial dermis becomes denser and tbe ebaraeteristic subepidermal band is formed. It is likely tbat the oedema progressively disappear-s. We could not obser-ve the acantholysis in the epidermis which was described by Klug & Sonnichsen (1972), but homoger-iization of the tonofilai-nents could be seen in the basal cells. An interesting epidermal alteration was the presence of collagen fibrils in the intercellular space. A sir-i-iilar finding
KINT AND GEERTS
34
has been described in lichen sclerosus et atropbicus by Mann & Cowan (1973). It can be assumed that these fibrils probably originate from tbe dermis. Although it bas been shown by Prunier-as et al. (1969) that in vitro epidermal cells are capable of producing collagen, an epidermal origin can bardly be accepted. From our material it seems likely that the basal layer of tbe epidermal collagen can be enclosed by pseudopodes of basal cells. Tbe fibrils themselves wei-e probably dissolved in the intereellular spaees of the malpighian layer, beeause they could never be observed witbin the epidermal cells, or between tbe eells of tbe upper half of tbe epidermis. As Mann & Cowan (1973) bave already pointed out, tbe presenee of eollagen in tbe intereellular spaee indicates that in lichen selerosus et atr-opbicus tbe dern-ro-epidermal interrelationship is disturbed. This process migbt be specific for lichen sclerosus et atropbicus and could be one explanation for the band-like distribution of tbe histologie changes in tbis disease.
References Forssmann, W. G., Holzmann, H. & Cabre, J. (1964) Elektronenmikroskopische untersuchungen der Haut beim Lichen sclerosus et -atrophicus. Archiv fiir Klinisehe und experimentelle Dertnatologie 220, 584-599. Hadida, E., Sayag, 1. & Allouche, Y. (1970) A propos du lichen sclero-atrophique. Archives beiges de Dermatologie et de Syphiligraphie 26, 311-335. Hauser, W. (1958) Lichen scler-osus et atrophicus. In Dertnatologie und Vetierologie, ed. Gottron, H. & Schonfeld, W. II, pp. 876-881. Stuttgart: Georg Thieme Verlag.
Klug, H. & Sonnichsen, N. (1972) Elektronen optische Untersucbungen bei Lichen sklerosus et atrophicus. Dermatologische Monatschrift 158, 641-654. Kor-ting, G. W. & Holzmann, H. (1968) Nouveaux aspects du probleme de la sclerodei-mie. Archives beiges de Dertnatologie et de Syphiligraphie 21, 225-234. Mann, P. R. & Cowan, M. A. (1973) Ultrastructur-al changes in four cases of lichen-^sclerosus et atrophicus. Btitish Journal of Dermatology 89, 223-231. Montgomery, H. & HiH,W. R. (1940) Lichen sclerosus et atrophicus. Arehives of Dertnatology and Syphilology 42, 755-779. Montgomery, H. (1967) Dertttopathology, pp. 753-759 & 989-996. New York: Harber Ed. Nicolau, S. G. & Balus, L. (1966) Sur la localisation vulvaire du LSA. Derttiatotogica 132, 27-44. Prunieras, M. (1954) A propos des lichen atr-ophiques. Attnales de Dertnatologie et de Syphiiigraphie 81, 46-61. Prunieras, M., Frey, J., Garzolo, L. & Delescluse, C. (1969) Synthese du collagcne par les cellules de l'epiderme. Bulletin de Dertnatologie et de Syphiligraphie 76, 20-23. Reynolds, E. S. (1963) The use of lead citrate at high pH as an electron opaque stain in electron microscopy. Journal of Cetltdar Biology 17, 208-212. Rupee, M. & Braun-Falco, O. (1964) Electronen mikr-oskopische Untersuchungen ijber das Verhalten der Kollagen fibrillen der Haut bei Skleroderniie. Archiv fiir klinisehe und experimentelle Dermatologie 218, 543-560. Steigleder, G.K. & Raab, W. (1961) Lichen sclerosus et atrophicus. Arehives of Dermatology 84, 219-226. Suurmond, D. (1964) Lichen sclerosus et atrophicus of the vulva Arehives of Dertttatology 90, 143-152. Address: A. Kint Dept. of Dertnatology University of Ghent G he tit Belgiutn
Lichen Sclerosus et Atrophicus An Electron Microscopic Study A. KrNT AND M. L. GEErvrs
•,,
Department of Dermatology, University of Ghent, Belgium The ultrastruetural cbanges in seven cases of lichen sclerosus et atrophicus arc described. An interesting epidermal alteration was the presence of collagen fibrils in the intercelKiUu' space; furtbermore, the basal cells were altered by condensation and homogcnization of the tonofibrils. The basctncnt membrane was not uniform and often multilayered. The anchoring fibrils were numerous. In the cutis intertwining strands of fine filaments, bundles of immature collagen and normal collagen could be found. In lichen sclerosus et atrophicus the dermo-epiderrnal interrelationship is disturbed. (Received for publication Novend>er 27, 1974)
Lichen sclerosus et atrophicus is character'ized histologically by tbe presence of an amorphous and cellular band underneath the epidermis (Montgomery & Hill 1940, Hauser 1958, Steigleder & Raab 1961, Suurmond 1964, Montgomery 1967, Hadida et al, 1970), The electron tnicroscopic studies of the subepidermal homogeneous zone reveal the presence of immature collagen fibrils and of bundles of closely packed but thin fibers showing a regular periodicity (Forssmann et al. 1964, Nicolau & Balus 1966, Hadida et al. 1970, Klug & Sonnichsen 1972, Mann & Cowan 1973). The subepidermal basement membrane is often broadened, and according to Klug & Sonnichsen (1972) the basal epidermal cells may show dyskeratotic signs and acantholysis. Mann & Cowan (1973) described clumps of collagen and elastin passing through the basement membrane and penetrating into the epidermis. It thus appears that in lichen sclerosus et atrophicus a distinct dermo-
epiderrnal interrelation does exist. This phenomenon brought us to an electron microscopic study of seven cases of lichen sclerosus et atrophicus. Material and Methods
Seven cases of lichen sclerosus et atrophicus were studied: two were localized on the back, two on the vulva and three on the preputium. The clinical diagnosis was confirmed in all of the cases by histologic examination. The biopsy specimens were fixed in 2.5 % glutaraldehyde buffer'ed with 0.1 M Sorensen's buffer and postfixed in buffered 1 % Os04. The tissues were embedded in Durcupan ACM, Ultrathin sections were cut with a Reichert ultrarnicrotome and double stained with lead citr'ate and Uranyl-acetate (Reynolds 1963). They were examined with Siemens Elmiskop I at 80 KV.
LICHEN SCLEROSUS ET ATROPHICUS
31
Fig. 1. A.F.: Anchoring fibrils; C : Immatur'e and matur'e collagen fibrils; EC: Epidermal cell; T: tonofilaments; | : cleft formed between the basal cell and the basement membrane. X 14,000.
Results
Epidermis Tbe membrane of the basal cells which lies directly above the basement membrane sometimes showed rectilinear structure, but more often pseudopodes intruding into the papillary layer were seen (Fig. 1). These pseudopodes were delineated by an utidulating tnembrane having numerous half desmosomes (Fig, 3). Some of the pseudopodes enclosed bundles of collagen fibrils, which were not always separated from the cell by a basement membrane. On the lateral and upper cell walls many cytoplasmic processes and microvilli were observed. The cytoplasm of the basal cells was dense and contained numerous mitochondria, ribo-
somes, glycogen, a rudimentary rough-sur'faced endoplasmic reticulum, tonofilaments and tubular structures measuring 150-180 A in diameter. In some cells the tonofibrils were grouped in bundles, which were often homogenized as could be seen in dysker'atotic cells. The nucleoplasm was granular and surrounded by a smooth nuclear membrane. The intercellular spaces were widened in the deep layers of the epidermis. Sometimes in these spaces fibrils measuring 400-500 A and showing tbe characteristic striation of collagen could be observed (Fig. 2). No basement membrane separated the fibrils frotn the surrounding cells. Between the epidermal cells many lymphocytes and
KINT AND GEERTS
Fig. 2. C: collagen in the intercellular spaces of the epidermis; MC: malpighian cell; N: nucleus; T: tonofilaments. X 20,300.
some unidentified mononuclear cells witb clear cytoplasm were present. The melanocytes generally had very few melanin granules and in most of the cases typical Langerhans cells could also be observed. In the more superficial layers of the epidermis the cell structure was very similar to that of normal skin. Dertnis The basement membrane was generally separated from the epidermis by a clear zone of 300 A; in some places, however, the space between the basal cells and the underlying basement membrane is broadened and clefts are formed (Fig, 1). Sometimes immature collagen fibrils could be seen between the membrane and the basal epider-
mal cell. The basement membrane itself was not uniform and varied in tbickness from 300 A to 900 A. It was often multilayered. In some areas it was lacking. Underneath the basement membrane the papillary layer and the superficial dermis were often oedematous, but they were also very dense and contained various fibrils, viz. (Fig. 3): a. anchoring fibrils normal in appear'ence. b. intertwining strands of fine filatnents of 60 A. c. bundles of irntnature collagen fibers havitig diameters varying from 400 to 800 A and showing a periodicity of 450-550 A. d. normal collagen bundles.
LICHEN SCLEROSUS ET ATROPHICUS
33
Fi.i,'. 3. A.F.: Anchoring fibrils; BM: Basement mer-nbranc; C: Mature and immature collagen fibrils; EC: epidermal cell; f: fine fibr-ils (60 A). X 42,000.
Tbe elastin fibers were rare. Tber-e were only a few fibroblasls. Their form was irregular and tbeir cytoplasm dense and filled up with thin filaments, which could leave the cell and accur-nulate in tbe extracellular space. In some of the fibroblasts lar-ge lacunes could be seen, eontaining striated collagen fiber-s. The capillaries and their pericytes appeared normal. Discussion
Tbe electron microscopic appearance of the superficial dermis in lichen sclerosus ct atrophicus is similar to scleroderma. In both diseases the structure of tbe cutis is dense and composed of protocollagcn and collagen fibrils of various dimensions. Tbe
oedematous appearance of tbe papillary layer in some sections was only visible in the early stage of the disease. It can be cor-npared with tbe bistologic findings, whicb in early lesions show oedematous zones underneath the epidermis. As the disease progr-esses, the superficial dermis becomes denser and tbe ebaraeteristic subepidermal band is formed. It is likely tbat the oedema progressively disappear-s. We could not obser-ve the acantholysis in the epidermis which was described by Klug & Sonnichsen (1972), but homoger-iization of the tonofilai-nents could be seen in the basal cells. An interesting epidermal alteration was the presence of collagen fibrils in the intercellular space. A sir-i-iilar finding
KINT AND GEERTS
34
has been described in lichen sclerosus et atropbicus by Mann & Cowan (1973). It can be assumed that these fibrils probably originate from tbe dermis. Although it bas been shown by Prunier-as et al. (1969) that in vitro epidermal cells are capable of producing collagen, an epidermal origin can bardly be accepted. From our material it seems likely that the basal layer of tbe epidermal collagen can be enclosed by pseudopodes of basal cells. Tbe fibrils themselves wei-e probably dissolved in the intereellular spaees of the malpighian layer, beeause they could never be observed witbin the epidermal cells, or between tbe eells of tbe upper half of tbe epidermis. As Mann & Cowan (1973) bave already pointed out, tbe presenee of eollagen in tbe intereellular spaee indicates that in lichen selerosus et atr-opbicus tbe dern-ro-epidermal interrelationship is disturbed. This process migbt be specific for lichen sclerosus et atropbicus and could be one explanation for the band-like distribution of tbe histologie changes in tbis disease.
References Forssmann, W. G., Holzmann, H. & Cabre, J. (1964) Elektronenmikroskopische untersuchungen der Haut beim Lichen sclerosus et -atrophicus. Archiv fiir Klinisehe und experimentelle Dertnatologie 220, 584-599. Hadida, E., Sayag, 1. & Allouche, Y. (1970) A propos du lichen sclero-atrophique. Archives beiges de Dermatologie et de Syphiligraphie 26, 311-335. Hauser, W. (1958) Lichen scler-osus et atrophicus. In Dertnatologie und Vetierologie, ed. Gottron, H. & Schonfeld, W. II, pp. 876-881. Stuttgart: Georg Thieme Verlag.
Klug, H. & Sonnichsen, N. (1972) Elektronen optische Untersucbungen bei Lichen sklerosus et atrophicus. Dermatologische Monatschrift 158, 641-654. Kor-ting, G. W. & Holzmann, H. (1968) Nouveaux aspects du probleme de la sclerodei-mie. Archives beiges de Dertnatologie et de Syphiligraphie 21, 225-234. Mann, P. R. & Cowan, M. A. (1973) Ultrastructur-al changes in four cases of lichen-^sclerosus et atrophicus. Btitish Journal of Dermatology 89, 223-231. Montgomery, H. & HiH,W. R. (1940) Lichen sclerosus et atrophicus. Arehives of Dertnatology and Syphilology 42, 755-779. Montgomery, H. (1967) Dertttopathology, pp. 753-759 & 989-996. New York: Harber Ed. Nicolau, S. G. & Balus, L. (1966) Sur la localisation vulvaire du LSA. Derttiatotogica 132, 27-44. Prunieras, M. (1954) A propos des lichen atr-ophiques. Attnales de Dertnatologie et de Syphiiigraphie 81, 46-61. Prunieras, M., Frey, J., Garzolo, L. & Delescluse, C. (1969) Synthese du collagcne par les cellules de l'epiderme. Bulletin de Dertnatologie et de Syphiligraphie 76, 20-23. Reynolds, E. S. (1963) The use of lead citrate at high pH as an electron opaque stain in electron microscopy. Journal of Cetltdar Biology 17, 208-212. Rupee, M. & Braun-Falco, O. (1964) Electronen mikr-oskopische Untersuchungen ijber das Verhalten der Kollagen fibrillen der Haut bei Skleroderniie. Archiv fiir klinisehe und experimentelle Dermatologie 218, 543-560. Steigleder, G.K. & Raab, W. (1961) Lichen sclerosus et atrophicus. Arehives of Dermatology 84, 219-226. Suurmond, D. (1964) Lichen sclerosus et atrophicus of the vulva Arehives of Dertttatology 90, 143-152. Address: A. Kint Dept. of Dertnatology University of Ghent G he tit Belgiutn
