The Incidence and Probable Origin of Melanin in the Prostate

Vol. 104, July Printed in U.S.A.

THE JOURNAL OF UROLOGY

Copyright © 1970 by The Williams & Wilkins Co.

THE INCIDENCE AND PROBABLE ORIGIN OF :IVIELANIN IN THE PROSTATE RAMON A. GUILLAN*

AND

SAMUEL ZELMAN

From the Departments of Pathology and Jl!l edical Service, Veterans Administration Hospital, Tope/ca, and the University of Kansas Medical School, Kansas City, Kansas

Infrequent case reports on melanin in the prostate1· 3 and one probable example of prostatic melanoma 4 prompted a search to determine the incidence of melanin in prostates. Sections from 330 prostate glands obtained at autopsy were stained with hematoxylin aud eosin, the Gomori reaction for iron, the Fontana:vrasson stain with and without permanganate bleaching and Lillie's ferrous iron technique. Epithelium cells with melanin were found in 13 prostates (4 per cent). The brownish-yellm, granules were deceptively inconspicuous with routine hematoxylin and eosin stains. They did not take the iron stain but stained positively with Lillie's ferrous iron technique and the Fontana-Masson stain and bleached completely with permanganate. The cells containing melanin were mainly tall columnar but occasionally atrophic. The pigment granules were mostly in the basal portions of the cells but their distribution varied ..Marked hyperplasia with secondary budding; characterized the epithelial cells (fig. 1). Desquamated cells containing melanin were seen in the glandular lumina in some areas. In 2 prostates pigmented melanoblasts with small elongated dendritic processes were detected in the parenchyma. In one prostate the rnelanoblasts were in close relation to epithelium containing melanin (fig. 2). With the exception of the approximated dendritic melanoblasts, similar appearances have been described with prostatic blue nevus lesions. 2 • 3 ·Willis indicates that melanoblasts are as Accepted for publication Jnly 3, 1969. * Request for reprints: Veterans Administration Hospital, Topeka, Kansas 66622. 1 Goldman, R. L.: Melanogenic epithelium in the prostate gland. Amer. J. Clin. Path., 49: 75, 1968. 2 Nigogosyan, G., De La Pava, S., Pickren, J. W. and Woodruff, M. W.: Blue nevus of the prostate gland. Cancer, 16: 1963. 3 Simard, C., Rognon, L. and Pilorce, G.: Le probleme du naevus bleu prostatique. Ann. Anat. Path., 9: 469, 1964. 4 Berry, N. E. and Reese, L.: Malignant melanoma which had its first clinical manifestations in the prostate gland. J. Urol., 69: 286, 1953.

diverse in type as the number of tissues capable of forming melanin. 5 They are often found in the juxta-cutaneous ·mucous membranes. Abundant melanin pigment and occasional melanomas have been observed in mucosa! epithelium and in the glands of the nasal cavity, oral cavity, esophagus, parotid gland, gallbladder and vagina. 0· 11 A. malignant melanoma which clinically first appeared in the proRtate has been reported. The origin of the pigment in tumors containinp; melanin or hyperplasias of the skin remains uncertain-whether produced by the epithelial cells themselves 12 or formed non-neoplastic melanocytes and transferred to them. 13 • 14 The observation of melanoblasts in close association with prostatic epithelium containing; melanin in one of our cases favors transmission of the pigment rather than its formation by epithelium itself. 5 Willis, R. A.: Pathology of Tumours, 4th edit. London: Butterworths, pp. 915-936, 1967. 6 Ariel, I. M.: Malignant melanoma of the vagina. Report of a successfully treated case. Obstet. Gynec., 17: 222, 1961. 7 De La Pava, S., Nigogosyan, G., Pickren, J. W. and Cabrera, A.: Melanosis of the esophagus. Cancer, 16: 48, 1963. 8 Greene, G. W., Jr. and Bernier, J. L.: Primary malignant melanomas of the parotid gland. Oral Surg., 14: 108, 1961. 9 Lewis, M. G. and Martin, J. A.: Malignant melanoma of the nasal cavity in Ugandan Africans. Relationship of ectopic pigmentation, Cancer, 20: 1699, 1967. 10 Scofield, H. H.: The blue (Jadassohn-Tieche) nevus: a previously unreported intraoral lesion. J. Oral Surg., 17: 4, 1959. 11 Walsh, T. S., Jr.: Primary melanoma of gallbladder with cervical metastasis and year survival; first histologically proved case. Cancer, 9: 518, 1956. 12 Stewart, M. J. and Bonser, G. M.: Melaninforming epidermal. tumours of skin; study of 57 personally observed cases. J. Path. & Bact., 60: 21, 1948. 13 Lennox, B.: Pigment patterns in epithelial tumours of skin. J. Path. & Bact., 61: 587, 1949. 14 Lund, H. Z. and Kraus, J. M.: Melanotic tumors of the skin. Atlas of Tumor Pathology. sect. 1, fasc. 3, Washington, D.C.: Armed Forces Institute of Pathology, 1962.

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FIG. 1. A, prostatic hyperplastic epithelium containing melanin. Reduced from Fontana-Masson X200. B, high power view of A. Reduced from Fontana-Masson XSOO.

FIG. 2. Dendritic melanoblasts in prostatic parenchyma closely approximated to epithelium containing melanin. Reduced from Fontana-Masson XSOO.

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INCIDENCE AND PROBABLE ORIGIN OF MELANIN IN PROSTATE

Stromal melanoblasts within the prostate, similar to those seen in blue nevus of the skin, were attributed to possible migration from the neural crest. 2 Though the incidence of melanin in prostate is low (4 per cent), this gland must be considered as a possible site of origin of metastatic melanoma.

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dritic melanoblasts were present in the stroma of 2 prostates and, in some areas, these were in close relation to prostatic epithelium containing melanin. It seems reasonable to infer that the pigment was formed by melanoblasts and transferred to the prostatic epithelium, rather than that the epithelium itself was melanogenic.

SUMMARY

Melanin was detected by special stains in 13 of 330 prostates examined (4 per cent). Den-

Technical assistance was provided by Mr. William K. Gaines.