0022-534 7/81/1263-0333$02.00/0 Vol. 126, September Printed in U.S.A.
THE JOURNAL OF UROLOGY
Copyright© 1981 by The Williams & Wilkins Co.
PEYRONIE'S DISEASE: AN ELECTRON MICROSCOPIC STUDY J. S. VANDEBERG,* C. J. DEVINE, C. E. HORTON, K D. SOMERS, G. L. WRIGHT, JR., M. S. LEFFELL, D. M. DAWSON, S. H. GLEISCHMAN AND M. J. ROWE From the Divisions of Urology and Plastic Surgery, Norfolk General Hospital and Departments of Microbiology, Immunology and Biochemistry, Eastern Virginia Medical School, Norfolk, Virginia
An electron microscopic examination of penile plaques from 20 patients with Peyronie's disease generally agreed with the light microscopic interpretation for lesions of short duration. Our data additionally show evidence for a reorganization of the interstitial matrix in vascular areas of the tunica albuginea. Penile plaques demonstrated nerve demyelination in 4 patients and the presence of bacteria in L Myofibroblast cells were not observed. Numerous studies have been reported on the clinical symptoms associated with Peyronie's disease. Various chemical and physical treatments have been directed toward a nonsurgical approach of softening or eliminating penile fibrotic plaques in the tunica albuginea. However, success with these methods has been inconsistent and generally beneficial in <50 per cent of the patients. 1 In numerous instances elective surgery via the Horton-Devine dermal graft method has proved to be an alternative.2 Smith reported the histological pattern of this disease at the light microscopic level. 3• 4 Lesions of short duration show a predominant inflammatory infiltrate, while lesions of long duration exhibit extensive fibrosis and ossification. We herein provide the first detailed electron microscopic examination of penile plaques in Peyronie's disease. We examined the ultrastructural relationship of cells in loose and dense connective tissue in penile plaques and relate them, when possible, to findings reported previously in the literature. MATERIALS AND METHODS
Plaque and adjacent normal tissues were examined from 20 patients, ranging in age from 32 to 67 years. Most of these individuals had been on at least l form of therapy for several months preoperatively. All specimens of fibrotic plaques were obtained from the tunica albuginea with, in some instances, attached erectile tissue of the corpus cavemosum. Fibrotic plaques also were compared to other forms of control tissues from patients with scar or hypospadias repair. A visual description and freehand drawing were made of each specimen, and correlated with the patient and preoperative treatment. Surgically excised plaques and adjacent normal tissue, obtained in the operating room, were diced into 1 mm. 3 blocks and immediately fixed for 2 hours in cold (4C) buffered Karnovsky's fixative, pH 7.4. They subsequently were transported to the laboratory for post-fixation in 0.1 M. cacodylate buffered 1 per cent osmium tetroxide, pH 7.4, dehydrated through a graded series of ethanol and propylene oxide and embedded in epon 812. Thick sections (0.5 µm.) were taken and stained with toluidine blue azure II for light microscopy. Thin sections then were cut and mounted on unsupported 300 mesh grids and stained in uranyl acetate and lead citrate before viewing in Hitachi HU-llB and Zeiss 10 electron microscopes. RESULTS
Histological features of the plaque included ballooning endothelial cells and perivascular cuffing with lymphocytes (fig. 1), which closely resembled the description by Smith in lesions Accepted for publication October 31, 1980. * Current address: Core Electron Microscope Laboratory (151), Veterans Administration Medical Center, San Diego, California 92161.
of short duration. 3 ' 4 However, this observation also was noted in 3 patients with a 2 to 3-year clinical history of Peyronie's disease. Ultrastructural examination of vascular areas revealed several interesting features. Endothelial cell membranes often were totally disrupted, with electron dense particulate material filli.ng the lumen (fig. 2, A). The appearance of this substance frequently was interwoven with microfilaments peripheral to the original endothelial wall and extended to outer regions of dense collagen. Random patterns of ectopic calcification were observed frequently in this area. In 1 patient several vascular areas in the tunica albuginea demonstrated the presence of bacteria which, because of the ultrastructure, resembled gram-negative bacilli (fig. 2). These micro-organisms were noted as isolated aggregates in the lumen and, occasionally, in the free space between collagen bundles. In other vascular regions there was evidence of reorganization of the interstitial matrix, which was demonstrated by the presence of apparent elastogenesis occurring in numerous free spaces between collagen bundles (fig. 3). This figure shows developing elastin fibers somewhere intermediate to the appearance of oxytalan and elaunin fibers. 5 The intriguing aspect of this observation was that mast cells and macrophages gene erally were noted in dose association with this elastic material. Specifically, pseudopodial extensions of cell membranes appeared to envelope this material in the interstitial matrix. While this elastic substance was never noted in the cytoplasm of mast cells it was observed in the macrophage. In tissue from 4 individuals numerous fiber tracts demonstrated partial to complete fragmentation of myelin (fig. 4, A). Neurotubules and filaments were totally absent. Schwann cell cytoplasm exhibited zebra-like bodies, vacuolated mitochondria and an accumulation of lipid inclusions (fig. 5). Large electron dense inclusions also were obvious in these cells. In specimens of plaque tissue where the erectile tissue of the corpus cavemosum was attached, smooth muscle cell nuclei often were stellate-shaped and expanded through a large area of the cytoplasm. Surrounding these cells were occasional microfibrils in a fine amorphous material (fig. 6), which appeared to comprise most of the intercellular space and form the predominant bridge between neighboring smooth muscle cells. Tight junctions between adjacent cells were observed rarely. The cytoplasm of these smooth muscle cells contained an apparent normal complement of contractile fibrils, mitochondria and Golgi apparatus. Smooth muscle cells from the tunica albuginea of a hypospadias patient were joined by tight junctions. Unlike the smooth muscle cells in Peyronie's plaque these cells were surrounded by bundles of mature collagen fibers (fig. 7). Few nuclei in these control cells ever presented the stellate appearance associated with a state of contraction. 333
VANDE BERG AND ASSOCIATES
autoimmune disorder, perhaps antecedent to some vascular trauma, and be accompanied by a fibroproliferative tissue response. In support of these ideas our study generally corroborates the suggestions of Smith, in which there is microscopic evidence for a trend originating as a vasculitis in the tunica albuginea, leading to fibrosis and possible calcification. 3• 4 Data from our investigation contribute several new additions to the interpretations by Smith. Calcification was observed in 2 patients with lesions of short duration. Such a condition might suggest that some individuals possess a predisposition toward an accelerated form of fibrosis. A degeneration and/or reorganization of con-
Fm. 1. Cross section of perivascular collar shows lymphocyte infiltration. Reduced from Xl,600.
Fm. 3. In many vascular areas mast cell membranes (M) surround elastic-like material (e) in interstitial matrix. Note presence of microfilaments (mf) surrounding venule, which extends into regions of free space (arrow). Reduced from XS,300.
Fm. 2. A, electron micrograph of plaque demonstrates disrupted endothelial membrane (Ee) and occurrence of microfilamentous material (mf). Bacteria (B) aggregated in original vascular lumen. Reduced from X7,000. B, scanning electron micrograph of fractured plaque demonstrates red blood cell (Rbe) encapsulated in area of calcification (Ee). Bacteria (B) are obvious throughout this area. Reduced from X7,500. DISCUSSION
Peyronie's disease is a penile fibromatosis, the etiology of which is unknown. Possible causes of Peyronie's disease have been reviewed by Chesney,6 and Billig and associates 7 but minimal supporting evidence exists to explain the etiology and pathogenesis of this disease. Peyronie's disease frequently is accompanied by other types of fibromatoses, for example Dupuytren's contracture and plantar fibromatosis, 7 suggesting a possible immunological basis for these fibrocontractive disorders. The pathogenesis of these diseases may result from an
Fm. 4. A, cross section of nerve fiber tract shows axons (Ax) and fragmented myelin (Me). Reduced from X3,000. B, enlarged magnification of axon demonstrates fragmentation of myelin (Me). Neurotubules and filaments are entirely absent. Reduced from X59,000.
PEYRONIE'S DISEASE: ELECTRON MICROSCOPIC STUDY
FIG. 5. Cross section of individual myelinated axons. Note presence of electron dense bodies (V), lipid droplets (ld) and zeb:ra-like bodies (Z) in Schwann cell cytoplasm. Reduced from X3,400.
FIG. 6. Smooth muscle cells from plaque contain underlying corpus cavernosum. Note presence of amorphous particulate material surrounding each cell and elastic-like material (e). Middle cell contains nuclei indicative of myofibroblast cell but other key characters are absent. Reduced from ><16,000.
Za:rafonetis and Horrax suggested that altered serotonin-monoamine oxidase levels may be responsible for increases in fibrosis.8 Highton and Garrett reµorted that mast cells also are concerned with fibrillogenesis, and that serotonin and related substances may have a direct effect on collagen. 9 Such compounds also destroy normal electron microscopic appearances of collagen bundles. Related to these structural alterations we observed that the periodicity of collagen fibers ranged from 2,cl to 48 nm. in specimens of plaque, compared to an average of 62 nm. in our hypospadias controls. This decrease in of collagen bands was evident particularly in areas of calcification. The presence of bacteria in vascular areas of the tunica albuginea was observed in 1 patient whose plaque demonstrated extensive calcification. Smith also identified bacilli and cocci in the vicinity of the urethra but not in the tunica albuginea. 4 Similarly, Billig and associates reported the presence of micro, organisms specifically in the periurethral glands, 7 These findings were presented in relationship to the apparent inflammatory and fibrosing symptoms noted in Peyronie's disease. While the presence of bacteria has been an uncommon observation their role would be interesting if these micro-organisms had the capability of disrupting loose connective tissue through ronidase production. 10 In several other specimens of plaque our data show that there is a demyelination of nerve axons. N eurotubules and filaments were notably absent in fragmented fibers, whereas ated axons did not appear to be affected. We 11 and other investigators 12 have cited preservation of the neurovascular bundle as one of the critical factors in the outcome of the dermal graft procedure. While this is certainly a relevant consideration during excision our findings show that a certain amount of neuropathology occurs preoperatively. a,,,u~,ufi.H m the clinical evaluation of patients with Peyronie's disease we have found no cases of impotence caused by the disease per se 13 these findings must be considered in the evaluation of postop· erative patients. Finally, because of the contracted angular state of the in Peyronie's disease we paid particular attention in our vations to search for the myofibroblast cell that has been reported to be responsible for contraction in fibrotic plaques of breast implants,14 • 15 Dupuytren's contracture 16 and wound healing.17· 18 In several plaques certain unusual smooth muscle cells closely resembled the myofibroblast by possessing dense zones of fibrillar bundles and stellate nuclei. However, the fibrillar bundles 1) were not immediately beneath the plasma mem-, brane, 2) did not measure 40 to 80 angstrom units, 3) were not necessarily parallel to the long axis of the cell and 4) were not associated with nuclei that were multiply indented. While Ariyan and associates did report the presence of myofibroblasts in the tunica albuginea in 2 patients with Peyronie's disease it should be mentioned that their micrographs did not show many of the aforementioned key features that are characteristic the myofibroblast. 14 REFERENCES l. Devine, C. J., Jr. and Horton, C. E.: Surgical treatment of Peyronie's
Frn. 7. Control section from corpus cavemosum of hypospadias patient shows mature collagen formation in interstitial matrix. In comparison to figure 6 note absence of amorphous and elastic-like material. Reduced from X4,000.
nective tissue involving elastogenesis in free space between collagen bundles appears to be an integral part of this disease (figs. 2, A and 6). Associated with this open area we have observed mast cells, specifically associated with elastic fibers. It generally is accepted that the products of mast cells, histamine and serotonin are associated with inflammatory reactions.
disease with a dermal graft. J. Urol., 111: 44, 1974. 2, Horton, C. E. and Devine, C. J., Jr.: Peyronie's disease. Plast Reconstr. Surg., 52: 503, 1973. 3. Smith, B. H.: Peyronie's disease. Amer. J. Clin. Path., 45: 670, 1966, 4. Smith, B. H.: Subclinical Peyronie's disease. Amer, J. Clin. Path,, 52: 385, 1969. 5. Bossart, M. I., Spjut, H.J. and Scott, F. B.: Ultrastructural analysis of human penile corpus cavemosum. Urology, 15: 448, 1980. 6, Chesney, J.: Peyronie's disease. Brit. J. Urol., 47: 209, 1975. 7. Billig, R., Baker, R., Immergut, M. and Maxted, W,: Peyronie's disease. Urology, 6: 409, 1975, 8. Zarafonetis, C. J. D. and Horrax, T. M.: Treatment of disease with potassium para-aminobenzoate (Potaba). 81: 770, 1959. 9. Highton, T. C. and Garrett, M. H.: Some effects of serotonin a.nd
VANDE BERG AND ASSOCIATES
related compounds on human collagen. Lancet, 1: 1234, 1963. 10. Meyer, K.: The biological significance of hyaluronic acid and hyaluronidase. Physiol. Rev., 27: 335, 1947. 11. Wild, R. M., Devine, C. J., Jr. and Horton, C. E.: Dermal graft repair of Peyronie's disease: survey of 50 patients. J. Urol., 121: 47, 1979. 12. Palomar, J.M., Halikiopoulos, H. and Thomas, R.: Evaluation of the surgical management of Peyronie's disease. J. Urol., 123: 680, 1980. 13. Jones, W. J., Horton, C. E. and Devine, C. J., Jr.: Psychological aspects of Peyronie's disease. Unpublished data. 14. Ariyan, S., Enriquez, R. and Krizek, T. J.: Wound contraction and fibrocontractive disorders. Arch. Surg., 113: 1034, 1978.
15. Rudolph, R., Abraham, J., Vecchione, T., Guber, S. and Woodward, M.: Myofibroblasts and free silicon around breast implants. Plast. Reconstr. Surg., 62: 185, 1978. 16. Gabbiani, G. and Majno, G.: Dupuytren's contracture: fibroblast contraction? An ultrastructural study. Amer. J. Path., 66: 131, 1972. 17. Gabbiani, G., Chaponnier, C. and Hiittner, I.: Cytoplasmic filaments and gap functions in epithelial cells and myofibroblasts during wound healing. J. Cell Biol., 76: 561, 1978. 18. Gabbiani, G.: The role of contractile proteins in wound healing and fibrocontractive diseases. In: Methods and Achievements in Experimental Pathology. Edited G. Gabbiani. Basel: S. Karger, vol. 9, chapt. 8, p. 187, 1979.