FIBROUS HISTIOCYTOMA JAMES
B. KAROL,
ANTHONY EMIL
OF BLADDER
M.D.
A. EASON,
A. TANAGHO,
M.D. M.D.
From the Division of Urology, University of California School San Francisco, California
ABSTRACT -A case of benign 5brou.s rare, and criteria for defining malignant important.
of Medicine,
histiocytoma of the bladder is presented. The occurrence is potential are unreliable. Careful follow;-up emlluations are
Fibrous histiocytoma, a tumor of mesenchymal origin, rarely involves the urinary tract. A case of intravesical fibrous histiocytoma with concomitant acute urinary retention is presented. To our knowledge such a lesion located in the bladder has been previously reported only once. 1 Case Report A thirty-three-year-old man was admitted to the hospital because of acute urinary retention. Catheterization yielded 400 ml. of bloody urine which proved to be uninfected. The patient had had obstructive voiding symptoms, which became progressively worse for one and one-half years. He had had one previous episode of gross Prostatitis had been diagpainful hematuria. nosed and treated with antibiotics. Physical examination disclosed an orangesized mass situated above the prostate and palpable both transabdominally and rectally. Routine laboratory studies yielded results with the exception of within normal range, urinalysis which disclosed the presence of blood. Excretory urography and cystography demonstrated a large intravesical filling defect without ureteral obstruction or displacement (Fig. 1). At cystoscopy, a tumor mass with apparently normal overlying mucosa was visualized, projecting
UROLOGY
I DECEMBER1977
/ VOLUMEX,
NUlLfBER6
FIGURE 1. Excretory urogram shows large intravesical filling defect without ureteral involvement.
593
FIGURE 2. (A) Low-power photomicrograph. Epithelial sur$ace of encapsulated tumor shows erosion with subjacent inj!ammation and edema. (B) Deeper portion of lesion shows increased fibrous stroma and variable cellularity. (C) Rare mitotic figures seen in high-power photomicrograph.
from midtrigone just within the bladder neck. Identification of either ureter-al orifice was impossible because of the bulky nature of the lesion. Perineal needle biopsy showed benign fibrous tissue. On a subsequent pelvic sonogram a solid mass could be seen within the urinary bladder. This finding was confirmed by computerized tomograpy (CT) body scanning, which delineated a 7 by 8 cm. midpelvic mass, completely surrounded on its superior and lateral margins by bladder. Diagnostic studies for possible metastases did not disclose any. On transvesical exploration a cleavage plane was established between the bladder trigone and the mass, which was then bluntly enucleated with relative ease. The posterior bladder wall was left intact, and hemostasis was obtained with electrocoagulation and hemostatic sutures. To insure integrity of the upper urinary tract both ureters were catheterized with 8 F pediatric feeding tubes. Postoperative recovery was uneventful. Histopathologic
examination
The specimen measured 8 by 10 by 6.5 cm. and weighed 239 Cm. It was a solid mass, with a pale red-gray to grayish tan external surface, and a homogenous glistening white appearance on the cut surface. Microscopically, the encapsulated tumor showed considerable variation in density and cellularity. Much of the subcapsular
594
region was edematous, with oval to spindleshaped cells, containing round to oval nuclei (Fig. 2A). In the denser regions of the lesion there was increased cellularity, as well as increased fibrous stroma (Fig. 2B). Rare round mitotic figures were seen (Fig. 2C). On trichrome staining an extensive amount of fibrous connective tissue could be visualized. Because of the uniformity of the histologic picture and the absence of mitotic figures, it was believed that the lesion was nonaggressive. Comment Histiocytic tumors most commonly involve the skin, soft tissue, muscles, tendons, and joints. However, they have been reported in locations such as the pancreas, respiratory tree, scrotum, and spermatic cord.2-5 They rarely occur in the urinary tract. Only 5 cases of renal involvement2*6,7 and 1 case of bladder involvement’ have been reported. Histiocytes are phagocytic cells belonging to the reticuloendothelial system. They have been shown to be facultative fibroblasts, capable of altering tumor appearance by the degree to which they assert their fibroblastic potential.2,8 This variability has led to the extremely confusing classification of histiocytic tumors as dermatofibroma, sclerosing hemangioma, fibroxanthoma, dermatofibrosarcoma protuberans, and neurofibroma.
UROLOGY
/ DECEMBER1977
/ VOLUMEX.
NUMBER6
University of California, A-644
Kauffman and Stout2 in reviewing histiocytic tumors in children, divided them into two groups: those containing more fibrous elements were called fibrous xanthomas, and those with little fibrous tissue were called histiocytomas. Potential for malignancy may be present in these tumors, but they generally are benign. However, the various criteria for histologically defining benign and malignant groups have proved unreliable. 2 In general, malignancy is associated with tumor cell pleomorphism and mitosis. Moreover, if excision is incomplete, residual tumors will grow and result in local recurrence. Our patient’s tumor was interpreted as benign because of its uniformity and lack of atypia. Nevertheless, to detect the development of possible latent malignancy, we plan to follow up this case with frequent cystoscopic evaluations.
UROLOGY
/
DECEMBER
1977
/
VOLUME
X, NUMBER
San Francisco,
California 94143 (DR. TANAGHO)
References 1. Stearns MD, et al: Fibrous histiocytoma of the bladder, J. Ural. 115: 114 (1976). 2. Kauffman SL, and Stout AP: Histiocytic tumors (fibrous xanthoma and histiocytoma) in children, Cancer 14: 469 (1961). 3. Hakimi M, Pais RP, Fine G, and Davila IC: Fibrous his_ tiocytoma of the’trachea, Chest 68: 367 (1975). 4. O’Brien JE, and Stout AP: Malignant fibrous xanthomas, Cancer 17: 1145 (1964). 5. Margules, RM, Allen RE, and Dunphy JE: Pancreatic tumor of mesenchymal origin presenting as obstruction jaundice, Am. J. Surg. 131: 357 (1967). _ 6. Klues RC. Farah RN. and Cernv IC: Renal mahenant histiocytoma: J. Ural. 112: 727 (1974). ’ ’ 7. Palma LD, Oaeta JF, Kenny GM, and Murphy GP: Perirenal fibrous xanthoma: unusual retroperitoneal tumor diagnosis and treatment, J. Surg. Oncol. 2: 45 (1970). 8. Ozello L, Stout AP, and Murray MR: Cultural characteristics of malignant histiocytomas and fibrous xanthomas, Cancer 16: 331 (1963).
6
595
B. KAROL,
ANTHONY EMIL
OF BLADDER
M.D.
A. EASON,
A. TANAGHO,
M.D. M.D.
From the Division of Urology, University of California School San Francisco, California
ABSTRACT -A case of benign 5brou.s rare, and criteria for defining malignant important.
of Medicine,
histiocytoma of the bladder is presented. The occurrence is potential are unreliable. Careful follow;-up emlluations are
Fibrous histiocytoma, a tumor of mesenchymal origin, rarely involves the urinary tract. A case of intravesical fibrous histiocytoma with concomitant acute urinary retention is presented. To our knowledge such a lesion located in the bladder has been previously reported only once. 1 Case Report A thirty-three-year-old man was admitted to the hospital because of acute urinary retention. Catheterization yielded 400 ml. of bloody urine which proved to be uninfected. The patient had had obstructive voiding symptoms, which became progressively worse for one and one-half years. He had had one previous episode of gross Prostatitis had been diagpainful hematuria. nosed and treated with antibiotics. Physical examination disclosed an orangesized mass situated above the prostate and palpable both transabdominally and rectally. Routine laboratory studies yielded results with the exception of within normal range, urinalysis which disclosed the presence of blood. Excretory urography and cystography demonstrated a large intravesical filling defect without ureteral obstruction or displacement (Fig. 1). At cystoscopy, a tumor mass with apparently normal overlying mucosa was visualized, projecting
UROLOGY
I DECEMBER1977
/ VOLUMEX,
NUlLfBER6
FIGURE 1. Excretory urogram shows large intravesical filling defect without ureteral involvement.
593
FIGURE 2. (A) Low-power photomicrograph. Epithelial sur$ace of encapsulated tumor shows erosion with subjacent inj!ammation and edema. (B) Deeper portion of lesion shows increased fibrous stroma and variable cellularity. (C) Rare mitotic figures seen in high-power photomicrograph.
from midtrigone just within the bladder neck. Identification of either ureter-al orifice was impossible because of the bulky nature of the lesion. Perineal needle biopsy showed benign fibrous tissue. On a subsequent pelvic sonogram a solid mass could be seen within the urinary bladder. This finding was confirmed by computerized tomograpy (CT) body scanning, which delineated a 7 by 8 cm. midpelvic mass, completely surrounded on its superior and lateral margins by bladder. Diagnostic studies for possible metastases did not disclose any. On transvesical exploration a cleavage plane was established between the bladder trigone and the mass, which was then bluntly enucleated with relative ease. The posterior bladder wall was left intact, and hemostasis was obtained with electrocoagulation and hemostatic sutures. To insure integrity of the upper urinary tract both ureters were catheterized with 8 F pediatric feeding tubes. Postoperative recovery was uneventful. Histopathologic
examination
The specimen measured 8 by 10 by 6.5 cm. and weighed 239 Cm. It was a solid mass, with a pale red-gray to grayish tan external surface, and a homogenous glistening white appearance on the cut surface. Microscopically, the encapsulated tumor showed considerable variation in density and cellularity. Much of the subcapsular
594
region was edematous, with oval to spindleshaped cells, containing round to oval nuclei (Fig. 2A). In the denser regions of the lesion there was increased cellularity, as well as increased fibrous stroma (Fig. 2B). Rare round mitotic figures were seen (Fig. 2C). On trichrome staining an extensive amount of fibrous connective tissue could be visualized. Because of the uniformity of the histologic picture and the absence of mitotic figures, it was believed that the lesion was nonaggressive. Comment Histiocytic tumors most commonly involve the skin, soft tissue, muscles, tendons, and joints. However, they have been reported in locations such as the pancreas, respiratory tree, scrotum, and spermatic cord.2-5 They rarely occur in the urinary tract. Only 5 cases of renal involvement2*6,7 and 1 case of bladder involvement’ have been reported. Histiocytes are phagocytic cells belonging to the reticuloendothelial system. They have been shown to be facultative fibroblasts, capable of altering tumor appearance by the degree to which they assert their fibroblastic potential.2,8 This variability has led to the extremely confusing classification of histiocytic tumors as dermatofibroma, sclerosing hemangioma, fibroxanthoma, dermatofibrosarcoma protuberans, and neurofibroma.
UROLOGY
/ DECEMBER1977
/ VOLUMEX.
NUMBER6
University of California, A-644
Kauffman and Stout2 in reviewing histiocytic tumors in children, divided them into two groups: those containing more fibrous elements were called fibrous xanthomas, and those with little fibrous tissue were called histiocytomas. Potential for malignancy may be present in these tumors, but they generally are benign. However, the various criteria for histologically defining benign and malignant groups have proved unreliable. 2 In general, malignancy is associated with tumor cell pleomorphism and mitosis. Moreover, if excision is incomplete, residual tumors will grow and result in local recurrence. Our patient’s tumor was interpreted as benign because of its uniformity and lack of atypia. Nevertheless, to detect the development of possible latent malignancy, we plan to follow up this case with frequent cystoscopic evaluations.
UROLOGY
/
DECEMBER
1977
/
VOLUME
X, NUMBER
San Francisco,
California 94143 (DR. TANAGHO)
References 1. Stearns MD, et al: Fibrous histiocytoma of the bladder, J. Ural. 115: 114 (1976). 2. Kauffman SL, and Stout AP: Histiocytic tumors (fibrous xanthoma and histiocytoma) in children, Cancer 14: 469 (1961). 3. Hakimi M, Pais RP, Fine G, and Davila IC: Fibrous his_ tiocytoma of the’trachea, Chest 68: 367 (1975). 4. O’Brien JE, and Stout AP: Malignant fibrous xanthomas, Cancer 17: 1145 (1964). 5. Margules, RM, Allen RE, and Dunphy JE: Pancreatic tumor of mesenchymal origin presenting as obstruction jaundice, Am. J. Surg. 131: 357 (1967). _ 6. Klues RC. Farah RN. and Cernv IC: Renal mahenant histiocytoma: J. Ural. 112: 727 (1974). ’ ’ 7. Palma LD, Oaeta JF, Kenny GM, and Murphy GP: Perirenal fibrous xanthoma: unusual retroperitoneal tumor diagnosis and treatment, J. Surg. Oncol. 2: 45 (1970). 8. Ozello L, Stout AP, and Murray MR: Cultural characteristics of malignant histiocytomas and fibrous xanthomas, Cancer 16: 331 (1963).
6
595
