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Computed tomography and ultrasound in diagnosis of pelvic lipomatosis
COMPUTED
TOMOGRAPHY
IN DIAGNOSIS
OF PELVIC
AND ULTRASOUND LIPOMATOSIS
PAUL A. CHURCH, M.D. ELIAS KAZAM, M.D. From the Department of Surgery (Urology), James Buchanan Brady Foundation, and Department of Radiology, The New York HospitalCornell Medical Center, New York, New York
ABSTRACT - Computed tomography (CT) and ultrasound are emerging as useful diagnostic adjuvants in the confirmation of pelvic lipomatosis. A case of pelvic lipomatosis studied by CT and sonography is presented. These two techniques offer greater precision in the demonstration of fatty tissue density within the true pelvis. The findings appear characteristic and unique. CT and ultrasound confkmation of pelvic lipomatosis provide added confidence in an accurate clinical diagnosis and may obviate the need for diagnostic surgical exploration.
Pelvic lipomatosis is a rare condition characterized by the deposition of an excessive amount of benign adipose tissue in the bony pelvis. Symptoms and complications are related to the compression of pelvic structures. The clinical findings and radiographic characteristics have been thoroughly described by other authors. l-3 Some authors believe that these clinical features alone are sufficient for an accurate diagnosis, while others advocate surgical exploration and biopsy to confirm the diagnosis of pelvic lipomatosis. More recently, the usefulness of computed for the tomography (CT) h as been reported confirmation of 2 cases of pelvic lipomatosis.4 It was suggested that the CT features were unique, as well as diagnostic. We report an additional case of pelvic lipomatosis examined by both CT and sonography. The two techniques indeed do appear to offer special diagnostic capabilities that are valuable in the confirmation of pelvic lipomatosis. Case Report A fifty-year-old black man had a twenty-five year history of recurring lower urinary tract including frequency, dysuria, symptoms, urethral discharge, and perineal pain. Sterile
UROLOGY
/
DECEMBER
1979
/
VOLUME
XIV,
NUMBER
pyuria and a boggy-feeling prostate were often present, and he was treated for “chronic prostatitis.” The development of bilateral varicoceles and a left inguinal hernia prompted further evaluation. He was normotensive, and the prostate was described as “high-riding.” An intravenous pyelogram revealed increased lucency in the pelvis and a “gourd-shaped” bladder. There was elevation of the bladder base and medial deviation of the distal ureters (Fig. 1A). A large bladder residual was present after voiding. A barium enema showed straightening and narrowing of the rectosigmoid with displacement of the sigmoid colon out of the pelvis (Fig. 1B). A presumptive diagnosis of pelvic lipomatosis was made, and sonography and CT were performed to evaluate further the soft tissues of the pelvis. Ultrasound revealed evidence of extensive echogenicity within the pelvis consistent with large deposits of fat (Fig. 2A and B). CT showed tissue surrounding the bladder and compressing its lateral walls (Fig. 2C). CT attenuation values confirmed this tissue to be fat density. There was no evidence of other soft tissue masses or adenopathy. At cystoscopy the posterior urethra was found to be elongated with elevation of the bladder neck. There were marked inflammatory changes
6
631
FIGURE 2. (A) Sagittal and (B) transverse sections show ultrasound appearance offEuid-j&d bladder (Bl) surrounded by large amounts of echogenic fat (j). (C) CT section of pelvis clearly showing bladder (B’) and seminal vesicles (s) compressed by homogenous fat (f3. Rectum (r) is seen posteriorly. (Adapted from Behan and Kazams with permission.)
of the prostatic urethra and bladder base. A left inguinal herniorraphy and varicocelectomy were performed, followed in several days by a transurethral resection of benign prostate tissue, in an effort to relieve any obstructive components to the patient’s voiding difficulties. Postoperatively, he continues to suffer from irritative urinary symptoms, including &equency, dysuria, urgency, and urge incontinence. The patient has been followed for over one year without deterioration in the appearance of the upper tracts. Comment This case demonstrates the typical features of pelvic lipomatosis. Clinically, the long history of irritable lower urinary tract symptoms and a “high-riding” prostate on rectal examination are
632
suggestive of the diagnosis. The presence of residual urine and lack of hypertension are somewhat unusual, however. The radiographic appearance by intravenous pyelogram and barium enema is typical of pelvic lipomatosis. Moreover, the cystoscopic appearance of an elongated posterior urethra and proliferative cystitis is typical of patients with this disorder. Our interest in the sonographic and CT evaluation of fatty tissues prompted study of this patient. In our experience most fatty tumors and tissues are markedly echogenic.5 The dense, featureless echoes in this patient’s pelvic sonogram represent fat surrounding the fluidfilled bladder. CT scanning offers a unique opportunity to delineate and identify tissues by their cross-sectional density, i.e., attenuation value. This ability appears to be especially
UROLOGY
/
DECEMBER
1979
/
VOLUME
XIV,
NUMBER
6
applicable to the evaluation of soft tissue masses in the bony pelvis. The CT scan in this patient clearly shows the bladder to be surrounded by homogenous tissue of fat density. Other pelvic structures are seen, including the seminal vesicles and rectum, but no abnormal masses or adenopathy are visible aside from the excessive amount of pelvic fat. The examination supports the conclusion of Gerson, Gerzof, and Robbins that the CT features are probably unique and diagnostic. While many investigators contend that a correct diagnosis can be made from the clinical characteristics and radiographic features alone,6 others insist that surgical exploration for tissue confirmation is essential.“s In the former school, perhaps the most important diagnostic criteria is the “gourd-shaped’ bladder with the radiolucent “halo.” It has been stated that this is the key to the diagnosis, since pelvic lipomatosis is the only process which will compress the bladder bilaterally and also give increased in obese palucency to the pelvis. However, tients the pelvic lucency is often difficult to appreciate, even with low-kilovoltage enhancement films. The barium enema findings are complementary to the features on the intravenous pyelogram but can be simulated by other conditions, including lymphoma and metastatic carcinoma. Pelvic angiography only has been useful in a rather negative way, by &riling to reveal the existence of tumor vessels. The. proponents of surgical exploration stress the importance of excluding malignant disease beyond any doubt. They cite cases in which lymphoma, metastatic carcinoma of the prostate, and retrovesical liposarcoma may present with a similar roentgenographic picture.g
It would appear that sonography and computed tomography may now offer the extra margin of diagnostic confidence to make surgical confirmation of pelvic lipomatosis obsolete. CT provides quantitative data regarding tissue density and, therefore, a more precise identification of fatty tissues. The findings demonstrated in this case and the 2 cases previously reported indeed do appear sufficiently unique so as to support the diagnostic value of CT in the evaluation of pelvic lipomatosis. The ultrasound features are complementary to CT, although less specific. The examination is easily performed and noninvasive. It is believed that these two techniques represent an important diagnostic adjuvant to conventional radiologic studies and virtually assure an accurate clinical diagnosis.
UROLOGY
6
/
DECEMBER
1979
/
VOLUME
XIV,
NUMBER
525 East 68th Street New York, New York 10021 (DR. CHURCH) References 1. Fogg L, and Smith W: Pelvic lipomatosis: a condition simulating pelvic neoplasm, Radiology 90: 558 (1968). 2. Lucey DT, and Smith MJV: Pelvic lipomatosis, J. Ural. 195: 341 (1971). 3. Sacks SA, and Drenick EJ: Pelvic lipomatosis: effect of diet, Urology 6: 609 (1975). 4. Gerson ES, Gerzof SC, and Robbins AH: CT confirmation of pelvic lipomatosis: two cases, AJR 129: 338 (1977). 5. Behan M, and Kazam E: The echographic characteristics of Eztty tissues and tumors, Radiology 129: 143 (1978). 6. Moss AA, Clark RE, Goldberg HI, and Pepper HW: Pelvic lipomatosis: a roentgenographic diagnosis, AJR 115: 411 (1972). 7. Witten DM, Myers GH, and Utz DC: In: Emmett’s Clinical Urography, 4th ed., Philadelphia, Saunders, 1977, p. 2236. 8. Abbott DA, and Skinner DG: Congenital venous anomalies associated with pelvic lipomatosis (a case report), J. Ural. 112: 739 (1974). 9. Nussbaum PS: Carcinoma of the prostate presenting as pelvic lipomatosis, Surg. Clin. North Am. 52: 405 (1972).
633
TOMOGRAPHY
IN DIAGNOSIS
OF PELVIC
AND ULTRASOUND LIPOMATOSIS
PAUL A. CHURCH, M.D. ELIAS KAZAM, M.D. From the Department of Surgery (Urology), James Buchanan Brady Foundation, and Department of Radiology, The New York HospitalCornell Medical Center, New York, New York
ABSTRACT - Computed tomography (CT) and ultrasound are emerging as useful diagnostic adjuvants in the confirmation of pelvic lipomatosis. A case of pelvic lipomatosis studied by CT and sonography is presented. These two techniques offer greater precision in the demonstration of fatty tissue density within the true pelvis. The findings appear characteristic and unique. CT and ultrasound confkmation of pelvic lipomatosis provide added confidence in an accurate clinical diagnosis and may obviate the need for diagnostic surgical exploration.
Pelvic lipomatosis is a rare condition characterized by the deposition of an excessive amount of benign adipose tissue in the bony pelvis. Symptoms and complications are related to the compression of pelvic structures. The clinical findings and radiographic characteristics have been thoroughly described by other authors. l-3 Some authors believe that these clinical features alone are sufficient for an accurate diagnosis, while others advocate surgical exploration and biopsy to confirm the diagnosis of pelvic lipomatosis. More recently, the usefulness of computed for the tomography (CT) h as been reported confirmation of 2 cases of pelvic lipomatosis.4 It was suggested that the CT features were unique, as well as diagnostic. We report an additional case of pelvic lipomatosis examined by both CT and sonography. The two techniques indeed do appear to offer special diagnostic capabilities that are valuable in the confirmation of pelvic lipomatosis. Case Report A fifty-year-old black man had a twenty-five year history of recurring lower urinary tract including frequency, dysuria, symptoms, urethral discharge, and perineal pain. Sterile
UROLOGY
/
DECEMBER
1979
/
VOLUME
XIV,
NUMBER
pyuria and a boggy-feeling prostate were often present, and he was treated for “chronic prostatitis.” The development of bilateral varicoceles and a left inguinal hernia prompted further evaluation. He was normotensive, and the prostate was described as “high-riding.” An intravenous pyelogram revealed increased lucency in the pelvis and a “gourd-shaped” bladder. There was elevation of the bladder base and medial deviation of the distal ureters (Fig. 1A). A large bladder residual was present after voiding. A barium enema showed straightening and narrowing of the rectosigmoid with displacement of the sigmoid colon out of the pelvis (Fig. 1B). A presumptive diagnosis of pelvic lipomatosis was made, and sonography and CT were performed to evaluate further the soft tissues of the pelvis. Ultrasound revealed evidence of extensive echogenicity within the pelvis consistent with large deposits of fat (Fig. 2A and B). CT showed tissue surrounding the bladder and compressing its lateral walls (Fig. 2C). CT attenuation values confirmed this tissue to be fat density. There was no evidence of other soft tissue masses or adenopathy. At cystoscopy the posterior urethra was found to be elongated with elevation of the bladder neck. There were marked inflammatory changes
6
631
FIGURE 2. (A) Sagittal and (B) transverse sections show ultrasound appearance offEuid-j&d bladder (Bl) surrounded by large amounts of echogenic fat (j). (C) CT section of pelvis clearly showing bladder (B’) and seminal vesicles (s) compressed by homogenous fat (f3. Rectum (r) is seen posteriorly. (Adapted from Behan and Kazams with permission.)
of the prostatic urethra and bladder base. A left inguinal herniorraphy and varicocelectomy were performed, followed in several days by a transurethral resection of benign prostate tissue, in an effort to relieve any obstructive components to the patient’s voiding difficulties. Postoperatively, he continues to suffer from irritative urinary symptoms, including &equency, dysuria, urgency, and urge incontinence. The patient has been followed for over one year without deterioration in the appearance of the upper tracts. Comment This case demonstrates the typical features of pelvic lipomatosis. Clinically, the long history of irritable lower urinary tract symptoms and a “high-riding” prostate on rectal examination are
632
suggestive of the diagnosis. The presence of residual urine and lack of hypertension are somewhat unusual, however. The radiographic appearance by intravenous pyelogram and barium enema is typical of pelvic lipomatosis. Moreover, the cystoscopic appearance of an elongated posterior urethra and proliferative cystitis is typical of patients with this disorder. Our interest in the sonographic and CT evaluation of fatty tissues prompted study of this patient. In our experience most fatty tumors and tissues are markedly echogenic.5 The dense, featureless echoes in this patient’s pelvic sonogram represent fat surrounding the fluidfilled bladder. CT scanning offers a unique opportunity to delineate and identify tissues by their cross-sectional density, i.e., attenuation value. This ability appears to be especially
UROLOGY
/
DECEMBER
1979
/
VOLUME
XIV,
NUMBER
6
applicable to the evaluation of soft tissue masses in the bony pelvis. The CT scan in this patient clearly shows the bladder to be surrounded by homogenous tissue of fat density. Other pelvic structures are seen, including the seminal vesicles and rectum, but no abnormal masses or adenopathy are visible aside from the excessive amount of pelvic fat. The examination supports the conclusion of Gerson, Gerzof, and Robbins that the CT features are probably unique and diagnostic. While many investigators contend that a correct diagnosis can be made from the clinical characteristics and radiographic features alone,6 others insist that surgical exploration for tissue confirmation is essential.“s In the former school, perhaps the most important diagnostic criteria is the “gourd-shaped’ bladder with the radiolucent “halo.” It has been stated that this is the key to the diagnosis, since pelvic lipomatosis is the only process which will compress the bladder bilaterally and also give increased in obese palucency to the pelvis. However, tients the pelvic lucency is often difficult to appreciate, even with low-kilovoltage enhancement films. The barium enema findings are complementary to the features on the intravenous pyelogram but can be simulated by other conditions, including lymphoma and metastatic carcinoma. Pelvic angiography only has been useful in a rather negative way, by &riling to reveal the existence of tumor vessels. The. proponents of surgical exploration stress the importance of excluding malignant disease beyond any doubt. They cite cases in which lymphoma, metastatic carcinoma of the prostate, and retrovesical liposarcoma may present with a similar roentgenographic picture.g
It would appear that sonography and computed tomography may now offer the extra margin of diagnostic confidence to make surgical confirmation of pelvic lipomatosis obsolete. CT provides quantitative data regarding tissue density and, therefore, a more precise identification of fatty tissues. The findings demonstrated in this case and the 2 cases previously reported indeed do appear sufficiently unique so as to support the diagnostic value of CT in the evaluation of pelvic lipomatosis. The ultrasound features are complementary to CT, although less specific. The examination is easily performed and noninvasive. It is believed that these two techniques represent an important diagnostic adjuvant to conventional radiologic studies and virtually assure an accurate clinical diagnosis.
UROLOGY
6
/
DECEMBER
1979
/
VOLUME
XIV,
NUMBER
525 East 68th Street New York, New York 10021 (DR. CHURCH) References 1. Fogg L, and Smith W: Pelvic lipomatosis: a condition simulating pelvic neoplasm, Radiology 90: 558 (1968). 2. Lucey DT, and Smith MJV: Pelvic lipomatosis, J. Ural. 195: 341 (1971). 3. Sacks SA, and Drenick EJ: Pelvic lipomatosis: effect of diet, Urology 6: 609 (1975). 4. Gerson ES, Gerzof SC, and Robbins AH: CT confirmation of pelvic lipomatosis: two cases, AJR 129: 338 (1977). 5. Behan M, and Kazam E: The echographic characteristics of Eztty tissues and tumors, Radiology 129: 143 (1978). 6. Moss AA, Clark RE, Goldberg HI, and Pepper HW: Pelvic lipomatosis: a roentgenographic diagnosis, AJR 115: 411 (1972). 7. Witten DM, Myers GH, and Utz DC: In: Emmett’s Clinical Urography, 4th ed., Philadelphia, Saunders, 1977, p. 2236. 8. Abbott DA, and Skinner DG: Congenital venous anomalies associated with pelvic lipomatosis (a case report), J. Ural. 112: 739 (1974). 9. Nussbaum PS: Carcinoma of the prostate presenting as pelvic lipomatosis, Surg. Clin. North Am. 52: 405 (1972).
633