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Nodular Histiocytic Prostatitis
Vol. 96, Sept.
THE JOURNAL OF UROLOGY
Copyright © 1966 by The Williams & Wilkins Co.
Printed in U.S.A.
NODULAR HISTIOCYTIC PROSTATITIS H. FOX From the Department of Pathology, University of Manchester, Manchester, England
It is well known that the clinical features of prostatic carcinoma may be closely mimicked by granulomatous prostatitis.1· 2 However, the histological picture of granulomatous prostatitis is fairly clear-cut and is characterized by dense lymphocyte and plasma cell infiltration of the gland; a moderate number of histiocytes are usually present and pseudo-tubercles, formed of epitheloid cells and giant cells, are a regular and diagnostic feature. Thus, the histological appearances of typical granulomatous prostatitis are quite distinct fron1 those of an adenocarcinoma and the differentiation of these two conditions usually causes little difficulty. In this paper a rare histological variant of granulomatous prostatitis is described-a variant which may be mistaken for carcinoma and cause considerable diagnostic difficulties.
characteristic of benign senile hyperplasia. However, for the most part the glandular tissue had been destroyed and replaced by well-demarcated cellular nodules. The nodules were approximately round or ovoid and of varying size. In some areas they were discrete and separated from one another by bands of fibromuscular tissue, while elsewhere the nodules showed a tendency to be confluent. Around some of the nodules the fibro-
CASE REPORT
W.H., a 58-year-old man, was admitted to the Manchester Royal Infirmary with a 2-week history of dysuria. He had also noticed some scalding on micturition and nocturia. He was otherwise well. Physical examination was negative except for the marked prostatic enlargement on rectal palpation. The prostate was smooth and firm. The patient was treated by transvesical prostatectomy, enucleation of the prostate being fairly easy. He made a good recovery and was fit and well when seen 6 months after his operation. The resected specimen consisted of multiple pieces of prostatic tissue that together weighed 29 gm. The glandular tissue had a multinodular appearance throughout. In a few areas the prostate showed the nodules of regular glandular and stromal hyperplasia Accepted for publication October 13, 1965. 1 Tanner, F. H. and McDonald, J. R.: Granulomatous prostatitis: histologic study of group of granulomatous lesions collected from prostate glands. Arch. Path., 36: 358-370, 1943. 2 Thompson, G. J. and Albers, D. D.: Granulomatous prostatitis: A condition which clinically may be confused with carcinoma of the prostate. .) . Urol., 69: 530-538, 1953.
FIG. 1. Well demarcated cellular nodules set in fibrous stroma. H & E X45
muscular interstitium was cmnpressed to form a pseudo-capsule. The nodules were composed almost entirely of large cells that closely resembled histiocytes. These cells had sharply demarcated borders and abundant, weak eosinophilic cytoplasm. In many of the cells the cytoplasm was foamy while in others it was coarsely vacuolated. The nuclei were round, though a few were ovoid or reniform. Many were centrally situated within the cell but some were eccentrically placed; they were vesicular with a sharply defined nuclear membrane. There was a large prominent nucleolus but otherwise little staining of nuclear chromatin. The histiocytic cells were regular with little pleomorphism and no mitotic figures. The intervening stroma showed a marked infiltration by lymphocytes together with a moderate number of plasma cells and an occasional polymorphocyte. In some areas the chronic inflammatory cell infiltration extended into the 372
NODULAR HISTIOCYTIC PROSTATITIS
Fm. 2. A, high power view of cellular nodule shows histiocytic cells.H &E X490 B, histiocytic cells in lumen of prostatic ducts. H & E X 120 peripheral part of the histiocytic nodules while in other parts of the gland there was a dense chronic inflammatory cell infiltration immediately round the nodules but no extension of this into the cell nodules. After prolonged searching a single pseudo-tubercle formed of epitheloid cells and a giant cell was seen. The prostatic ducts showed marked lymphocytic cuffing and some contained a mixture of polymorphocytes, lymphocytes and plasma cells in their lumen. However, many of the ducts contained numerous histiocytes similar to those seen in the parenchymal nodules (figs. 1 and 2). Histochemically, the histiocytic cells were negative when stained with periodic acid-Schiffhematoxylin stain. Frozen section stained with Sudan IV showed that a minority of the histiocytic cells contained a small amount of fat; however, many were lipid-free. The lipid present was non-birefringent. Formalin-fixed sections stained with Sudan black gave negative reactions. DISCUSSION
The histological appearances of this variant of chronic prostatitis may, at first sight, be easily confused with those of an adenocarcinoma of the
prostate. The differentiation rests partially on the regularity and uniformity of the cells and partially on the absence of any evidence of rapid growth. Thus, mitotic figures are not seen and the cellular nodules are well demarcated and well delineated-often with a surrounding pseudocapsule of condensed stroma. The nodules show no evidence of any tendency for cells to infiltrate out into the stroma. A further distinguishing feature of this condition is the absence of mucus. The presence of a non-specific chronic inflammatory infiltration is of little distinguishing value, for such an infiltration is no more marked than that seen in many cases of prostatic carcinoma. Similarly the presence of lipid is not a specific feature for fat may be demonstrated in most prostatic carcinomas. 3 It may be argued that these features only eliminate the possibility of malignant tumor and that the condition is in fact a benign tumor-either a xanthoma or a tumor of similar nature to the oncocytoma sometimes seen in the parotid or pancreas. However, the multinodular pattern of the lesion and the finding 3 Braunstein, H.: Staining lipid in carcinoma of prostate gland. Amer. J. Clin. Path., 41: 44-48,
1964.
374
FOX
of a typical pseudotubercle suggest that the lesion is in fact a variant of granulomatous prostatitis. This histiocytic type of prostatitis is rare; there appears to have been only 4 previously reported cases. The first case ,vas described by Kinoshita in 19204 and since then further cases have been reported by Scherrer, 5 Arnold 6 and Myhre. 7 In each of these cases the histological appearance was identical with that described here and all these authors, with the exception of Kinoshita, concluded that the lesion was essentially of an inflammatory nature. Kinoshita considered the appearances were those of a xanthomatous neoplasm. It is a curious fact that the urinary tract does appear, on occasion, to respond to chronic infection with a predominantly histiocytic cell response. Thus, Myhre described histiocytic nodular lesions of inflammatory origin occurring in the ureter, renal pelvis and bladder. 7 In each case, difficulty was experienced in distinguishing these lesions from a neoplasm. In the kidney, the condition of xanthogranulomatous pyelonephritis is well recognized and is characterized by nodules and sheets of histiocytes in the renal paren• Kinoshita, M.: Carcinoma xanthomatodes prostate. Z. Urol., 14: 193-19G, 1920. 5 Scherrer, M.: Tumorilhnliche wacherung histiocytii,rer phagocyten bei chronischer prostatitis. Frank£. Z. Path., 62: 155-loG, 1951. 6 Arnold, K.: Tumorilhnliche histiozytar knoten bei chronischer prostatitis. Z. Urol., 55: 219-223, 1962.
7 Myhre, E.: Chronic inflammation of the urinary tract resembling neoplastic growth. Acta Path. Microbiol. Scand., 59: 189-194, 1963.
chyma. 8- 11 The histological features of xanthogranulomatous pyelonephritis are, in fact, very similar to those of histiocytic prostatitis, and it must be considered that there is a particular tendency for this unusual type of chronic inflammatory response to occur in the urogenital tract. SUJ\Il\L\.RY
A case of an unusual variant of granulomatous prostatitis is described. This variant is characterized by nodular histiocytic replacement of glandular tissue. The histological differentiation of this lesion from carcinoma is discussed, and the reasons for considering this to be a granulomatous prostatitis are cited. The literature on the topic is briefly reviewed and it is concluded that the urogenital tract shmvs a particular tendency to react to chronic infection with a predominantly histiocytic cell response-often nodular. I am indebted to Nir. F. Nicholson for permission to quote the clinical details of this patient and to Mr. 13. W. Figg for the photomicrography. 8 Hatch, C. S. and Cockett, A. T. K.: Xanthogranulomatous pyelonephritis. J. l:rol.. 92: 585-
588, 1964.
'Saeed, S. M. and Fine, G.: Xanthomatous pyelonephritis. Amer. J. Clin. Path., 39: 616-625, 1963. 10
Selzer, D. W., Dahlin, D. C. and DeWeerd.
J. JVI.: Tumefactive xanthogranulonrntous pyelo: nephritis. Snrgery, 42: 874-883, 1957. 11
Smout, M. S., McAninch, L. N. and Wyatt,
J. K.: Tumefactive xanthogranulonmtous pyelonephritis. Brit. J. Urol., 35: 129-132, 1963.
THE JOURNAL OF UROLOGY
Copyright © 1966 by The Williams & Wilkins Co.
Printed in U.S.A.
NODULAR HISTIOCYTIC PROSTATITIS H. FOX From the Department of Pathology, University of Manchester, Manchester, England
It is well known that the clinical features of prostatic carcinoma may be closely mimicked by granulomatous prostatitis.1· 2 However, the histological picture of granulomatous prostatitis is fairly clear-cut and is characterized by dense lymphocyte and plasma cell infiltration of the gland; a moderate number of histiocytes are usually present and pseudo-tubercles, formed of epitheloid cells and giant cells, are a regular and diagnostic feature. Thus, the histological appearances of typical granulomatous prostatitis are quite distinct fron1 those of an adenocarcinoma and the differentiation of these two conditions usually causes little difficulty. In this paper a rare histological variant of granulomatous prostatitis is described-a variant which may be mistaken for carcinoma and cause considerable diagnostic difficulties.
characteristic of benign senile hyperplasia. However, for the most part the glandular tissue had been destroyed and replaced by well-demarcated cellular nodules. The nodules were approximately round or ovoid and of varying size. In some areas they were discrete and separated from one another by bands of fibromuscular tissue, while elsewhere the nodules showed a tendency to be confluent. Around some of the nodules the fibro-
CASE REPORT
W.H., a 58-year-old man, was admitted to the Manchester Royal Infirmary with a 2-week history of dysuria. He had also noticed some scalding on micturition and nocturia. He was otherwise well. Physical examination was negative except for the marked prostatic enlargement on rectal palpation. The prostate was smooth and firm. The patient was treated by transvesical prostatectomy, enucleation of the prostate being fairly easy. He made a good recovery and was fit and well when seen 6 months after his operation. The resected specimen consisted of multiple pieces of prostatic tissue that together weighed 29 gm. The glandular tissue had a multinodular appearance throughout. In a few areas the prostate showed the nodules of regular glandular and stromal hyperplasia Accepted for publication October 13, 1965. 1 Tanner, F. H. and McDonald, J. R.: Granulomatous prostatitis: histologic study of group of granulomatous lesions collected from prostate glands. Arch. Path., 36: 358-370, 1943. 2 Thompson, G. J. and Albers, D. D.: Granulomatous prostatitis: A condition which clinically may be confused with carcinoma of the prostate. .) . Urol., 69: 530-538, 1953.
FIG. 1. Well demarcated cellular nodules set in fibrous stroma. H & E X45
muscular interstitium was cmnpressed to form a pseudo-capsule. The nodules were composed almost entirely of large cells that closely resembled histiocytes. These cells had sharply demarcated borders and abundant, weak eosinophilic cytoplasm. In many of the cells the cytoplasm was foamy while in others it was coarsely vacuolated. The nuclei were round, though a few were ovoid or reniform. Many were centrally situated within the cell but some were eccentrically placed; they were vesicular with a sharply defined nuclear membrane. There was a large prominent nucleolus but otherwise little staining of nuclear chromatin. The histiocytic cells were regular with little pleomorphism and no mitotic figures. The intervening stroma showed a marked infiltration by lymphocytes together with a moderate number of plasma cells and an occasional polymorphocyte. In some areas the chronic inflammatory cell infiltration extended into the 372
NODULAR HISTIOCYTIC PROSTATITIS
Fm. 2. A, high power view of cellular nodule shows histiocytic cells.H &E X490 B, histiocytic cells in lumen of prostatic ducts. H & E X 120 peripheral part of the histiocytic nodules while in other parts of the gland there was a dense chronic inflammatory cell infiltration immediately round the nodules but no extension of this into the cell nodules. After prolonged searching a single pseudo-tubercle formed of epitheloid cells and a giant cell was seen. The prostatic ducts showed marked lymphocytic cuffing and some contained a mixture of polymorphocytes, lymphocytes and plasma cells in their lumen. However, many of the ducts contained numerous histiocytes similar to those seen in the parenchymal nodules (figs. 1 and 2). Histochemically, the histiocytic cells were negative when stained with periodic acid-Schiffhematoxylin stain. Frozen section stained with Sudan IV showed that a minority of the histiocytic cells contained a small amount of fat; however, many were lipid-free. The lipid present was non-birefringent. Formalin-fixed sections stained with Sudan black gave negative reactions. DISCUSSION
The histological appearances of this variant of chronic prostatitis may, at first sight, be easily confused with those of an adenocarcinoma of the
prostate. The differentiation rests partially on the regularity and uniformity of the cells and partially on the absence of any evidence of rapid growth. Thus, mitotic figures are not seen and the cellular nodules are well demarcated and well delineated-often with a surrounding pseudocapsule of condensed stroma. The nodules show no evidence of any tendency for cells to infiltrate out into the stroma. A further distinguishing feature of this condition is the absence of mucus. The presence of a non-specific chronic inflammatory infiltration is of little distinguishing value, for such an infiltration is no more marked than that seen in many cases of prostatic carcinoma. Similarly the presence of lipid is not a specific feature for fat may be demonstrated in most prostatic carcinomas. 3 It may be argued that these features only eliminate the possibility of malignant tumor and that the condition is in fact a benign tumor-either a xanthoma or a tumor of similar nature to the oncocytoma sometimes seen in the parotid or pancreas. However, the multinodular pattern of the lesion and the finding 3 Braunstein, H.: Staining lipid in carcinoma of prostate gland. Amer. J. Clin. Path., 41: 44-48,
1964.
374
FOX
of a typical pseudotubercle suggest that the lesion is in fact a variant of granulomatous prostatitis. This histiocytic type of prostatitis is rare; there appears to have been only 4 previously reported cases. The first case ,vas described by Kinoshita in 19204 and since then further cases have been reported by Scherrer, 5 Arnold 6 and Myhre. 7 In each of these cases the histological appearance was identical with that described here and all these authors, with the exception of Kinoshita, concluded that the lesion was essentially of an inflammatory nature. Kinoshita considered the appearances were those of a xanthomatous neoplasm. It is a curious fact that the urinary tract does appear, on occasion, to respond to chronic infection with a predominantly histiocytic cell response. Thus, Myhre described histiocytic nodular lesions of inflammatory origin occurring in the ureter, renal pelvis and bladder. 7 In each case, difficulty was experienced in distinguishing these lesions from a neoplasm. In the kidney, the condition of xanthogranulomatous pyelonephritis is well recognized and is characterized by nodules and sheets of histiocytes in the renal paren• Kinoshita, M.: Carcinoma xanthomatodes prostate. Z. Urol., 14: 193-19G, 1920. 5 Scherrer, M.: Tumorilhnliche wacherung histiocytii,rer phagocyten bei chronischer prostatitis. Frank£. Z. Path., 62: 155-loG, 1951. 6 Arnold, K.: Tumorilhnliche histiozytar knoten bei chronischer prostatitis. Z. Urol., 55: 219-223, 1962.
7 Myhre, E.: Chronic inflammation of the urinary tract resembling neoplastic growth. Acta Path. Microbiol. Scand., 59: 189-194, 1963.
chyma. 8- 11 The histological features of xanthogranulomatous pyelonephritis are, in fact, very similar to those of histiocytic prostatitis, and it must be considered that there is a particular tendency for this unusual type of chronic inflammatory response to occur in the urogenital tract. SUJ\Il\L\.RY
A case of an unusual variant of granulomatous prostatitis is described. This variant is characterized by nodular histiocytic replacement of glandular tissue. The histological differentiation of this lesion from carcinoma is discussed, and the reasons for considering this to be a granulomatous prostatitis are cited. The literature on the topic is briefly reviewed and it is concluded that the urogenital tract shmvs a particular tendency to react to chronic infection with a predominantly histiocytic cell response-often nodular. I am indebted to Nir. F. Nicholson for permission to quote the clinical details of this patient and to Mr. 13. W. Figg for the photomicrography. 8 Hatch, C. S. and Cockett, A. T. K.: Xanthogranulomatous pyelonephritis. J. l:rol.. 92: 585-
588, 1964.
'Saeed, S. M. and Fine, G.: Xanthomatous pyelonephritis. Amer. J. Clin. Path., 39: 616-625, 1963. 10
Selzer, D. W., Dahlin, D. C. and DeWeerd.
J. JVI.: Tumefactive xanthogranulonrntous pyelo: nephritis. Snrgery, 42: 874-883, 1957. 11
Smout, M. S., McAninch, L. N. and Wyatt,
J. K.: Tumefactive xanthogranulonmtous pyelonephritis. Brit. J. Urol., 35: 129-132, 1963.