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Diaphragmatic crus lipoma: a case report
Computerized Medical Imaging and Graphics PERGAMON
Computerized Medical Imaging and Graphics 22 (1998) 421±423
Diaphragmatic crus lipoma: a case report Orhan Oyar a,*, Gulgun Kayalioglu b, Ufuk Cagirici c a
Department of Diagnostic Radiology, Ege University, 35100, Bornova, Izmir, Turkey b Department of Anatomy, Ege University, 35100, Bornova, Izmir, Turkey c Department of Thoracic Surgery, Ege University, 35100, Bornova, Izmir, Turkey
Received 9 April 1998; received in revised form 24 September 1998; accepted 24 September 1998
Abstract Diaphragmatic crus lipoma is a very rare entity. In this case report, smooth, rounded masses of diaphragmatic lipoma, incidentally observed in a 37-year-old female on routine abdominal computed tomographic scanning is presented. q 1998 Elsevier Science Ltd. All rights reserved. Keywords: Lipoma; Diaphragm; Computed tomography
1. Case report
2. Discussion
During CT evaluation of a 37-year-old female patient suffering from pelvic pain, radiological features of pelvic in¯ammatory disease were observed. In the scans through the upper abdomen, the right diaphragmatic crus was observed as a linear homogeneous solid density, while the left crus showed a different morphology and a different density (Fig. 1). In three to four scans through the level of the left posterior cul de sac, two rounded masses and a band with normal crus density between them were present in the diaphragmatic crus. The masses showed a density measuring about 2100 Houns®eld units (HU) consistent with that of adipose tissue (Fig. 2). The crura on the anterior and posterior sides of the masses had a V-shaped or drinking glass-shaped morphology, con®rming the intrinsic origin of the lesion. When contiguous scans were examined, it was observed that the left diaphragmatic crus acquired its normal thickness, morphology and density in the proximal (Fig. 3) and distal (Fig. 4) parts of the lesion masses. We did not perform ®ne needle aspiration biopsy for con®rmation due to the small dimension of the masses, and high risk of damaging vital organs and tissues. Diagnostic surgical intervention was avoided because the lipoma was very small and the case was asymptomatic and malign degeneration of lipomas has not been reported in the literature.
The diaphragm is a dome-shaped, musculo®brous septum which separates the thoracic from the abdominal cavity. Its peripheral part consists of muscular ®bers which originate from the circumference of the thoracic outlet and converge to be inserted into a central tendon. The muscular ®bers of the diaphragm consist of sternal, costal and lumbar parts. The sternal part arises from two ¯eshy slips from the back of the xiphoid process, the costal part from the inner surface of the cartilages and adjacent portions of the lower six ribs on each side. The lumbar part arises from two aponeurotic ligaments named the medial and lateral lumbocostal ligaments from the lumbar vertebrae by two crura. Two crura join anteriorly in front of the spine by means of the median arcuate ligament in front of the abdominal aorta and the vertebral column [1,2]. Diaphragmatic lipomas are encapsulated, soft fatty tumors frequently occurring in obese patients. They are equally common in men and women, reported twice as often on the left side, mostly in a posterolateral location [3,4] and may occasionaly be bilateral [5]. Diaphragmatic lipomas are either sessile or pedunculated and anchored to the diaphragm or hourglass-shaped with an isthmus through the diaphragm and an extrathoracic extension [6]. Sessile lipomas are believed to develop from subpleural mature fatty tissue whereas hourglass-shaped lipomas develop from embryonally undifferentiated tissue [6]. Although there are very few cases reported, diaphragmatic lipomas are probably more common. Due to their stable and usually asymptomatic nature, they are
* Corresponding author at: 87 sok. Iyriboz Apt. No. 4 D, 14, 35040, Bornova, Izmir, Turkey. fax: 1 90-232-3390002.
0895-6111/99/$ - see front matter q 1998 Elsevier Science Ltd. All rights reserved. PII: S 0895-611 1(98)00053-6
422
O. Oyar et al. / Computerized Medical Imaging and Graphics 22 (1998) 421±423
Fig. 1. CT scan passing from the upper abdomen, showing varying density of the left diaphragmatic crus.
Fig. 3. CT scan passing from a section proximal to the diaphragmatic lipoma, showing normal morphology of the left diaphragmatic crus.
incidentally discovered mostly during diagnostic visualization techniques done for other different symptoms of the patients or at autopsy [7]. It has been reported that diaphragmatic lipomas may occasionally cause dry cough and thoracic pain [6]. Although diaphragmatic lipomas usually remain stable in size and have not been reported to degenerate into liposarcoma, they should be followed up in time with CT. Visualization of diaphragmatic crura is very limited with plain radiography. Only the inferior extents of diaphragmatic crura can be distinguished due to the contrast of retroperitoneal adipose tissue. Routine thoracoabdominal CT scanning is preferred to all other techniques in visualization of the crura because it allows the visualization of crura morphology and evaluation of their density. With the widespread usage of CT, diaphragmatic pathologies omitted in plain radiography can now be detected. This led to an increase in diagnosis of diaphragmatic lipomas and asymptomatic hernias and especially Bochdalek hernias.
Castillo and Shirkhoda [8] reported ®ve cases of diaphragmatic lipomas with CT. Ferguson and Westcott [7] also reported a case of diaphragmatic lipoma with CT, they con®rmed their diagnosis with postmortem examination. Diaphragmatic lipomas are frequently mistaken for hernias, especially Bochdalek hernias, and localized eventrations. Eventrations usually retain the general con®guration of the diaphragm, in contrast with the spherical or ovoid shape of lipomas [7]. Most of the Bochdalek hernias in adults contain fat, so they may erroneously be interpreted as diaphragmatic lipoma. Differential diagnosis of Bochdalek hernias from diaphragmatic lipoma is one of the most important dif®culties in diaphragmatic imaging. Bochdalek hernias have four characteristics de®ned with CT:
Fig. 2. CT scan showing a diaphragmatic lipoma as hypodense masses in the left diaphragmatic crus.
Fig. 4. CT scan passing from a section distal to the diaphragmatic lipoma, showing normal morphology of the left diaphragmatic crus.
1. Bochdalek hernias are round±oval masses, adjacent to the thoracic surface of the diaphragm, showing a density of 2130 to 2120 HU;
O. Oyar et al. / Computerized Medical Imaging and Graphics 22 (1998) 421±423
2. they are located in the posteromedial aspect of the hemidiaphragm; 3. there is a discontinuity in the muscular tissue of the diaphragm and a V-shaped con®guration is present; 4. the density of the diaphragmatic defect continues supradiaphragmatically and subdiaphragmatically [9±12]. In this case, a V-shaped con®guration was observed in the ventral and dorsal part of the left diaphragmatic crus, but no discontinuity was de®ned in the diaphragm. A very thin line of diaphragmatic density surrounding the lesion could be observed. The left diaphragmatic crus was returning to its normal con®guration and density here. The presence of nodular hypodense masses instead of a solid homogeneous mass con®rms that the case is an intrinsic pathology of the diaphragm. We propose that the V-shaped con®guration in the adjacent diaphragm musculature is not speci®c for Bochdalek hernias and any intrinsic pathology of the diaphragm having a different density can show a similar con®guration in diaphragmatic crura. Most important of all, the discontinuity of adipose tissue density in cranial and caudal parts, and continuity of the diaphragm caudally especially differentiates lipoma from retroperitoneal adipose tissue. Based on these facts, it is suggested that the presence of these rounded masses in left diaphragmatic crus is concordant with asymptomatic incidental diaphragmatic crus lipoma rather than a small Bochdalek hernia. 3. Summary During CT evaluation of a 37-year-old female patient suffering from pelvic pain, radiological features of pelvic in¯ammatory disease were observed. In the scans through the upper abdomen, the right diaphragmatic crus was observed as a linear homogenous solid density, while the left crus showed a different morphology and a different density. In three to four scans through the level of the left posterior cul de sac, two rounded masses were observed. The masses showed a density of about 2100 HU, consistent with that of adipose tissue and a band with normal crus density between them was present. The crura on the anterior and posterior sides of the masses had a V-shaped or drinking glass-shaped morphology. Fine needle aspiration biopsy and diagnostic surgical intervention biopsy for con®rmation was avoided due to the small dimension of the masses, high risk of damaging vital organs and tissues and benign nature of diaphragmatic lipoma.
References [1] Gray H. Gray's anatomy, 37th ed. In: Williams P, Warwick R., editors. London: Churchill Livingstone, 1989. [2] Silverman PM, Cooper C, Zeman RK. Lateral arcuate ligaments of the diaphragm: Anatomic variations at abdominal CT. Radiology 1992;185(1):105±108.
423
[3] Dalquen P. Lipoma of the diaphragm: Malformation or hernia?. Thoraxchir Vask Chir 1972;20(2):112±115. [4] Wiener MF, Chou WH. Primary tumors of the diaphragm. Arch Surg 1965;90(2):143±152. [5] Tihansky DP, Lopez GM. Bilateral lipomas of the diaphragm. NY State J Med 1988;88(3):151±152. [6] Kalen NA. Lipoma of the diaphragm. Scand J Resp Dis 1970;51(1):28±32. [7] Ferguson DD, Westcott JL. Lipoma of the diaphragm: Report of a case. Radiology 1976;118(3):527±528. [8] Castillo M, Shirkhoda A. Computed tomography of diaphragmatic lipoma. J Comput Tomogr 1985;9(2):167±170. [9] De Martini WJ, House AJS. Partial Bochdalek's herniation: computerized tomographic evaluation. Chest 1980;77(5):702±704. [10] Gale ME. Bochdalek hernia: prevalance and CT characteristics. Radiology 1985;156(2):449±452. [11] Shin MS, Mulligan SA, Baxley WA, Ho KJ. Bochdalek hernia of diaphragm in the adult: Diagnosis by computed tomography. Chest 1987;92(6):1098±1101. [12] Tarver RD, Conces Jr DJ, Cory DA, Vix VA. Imaging the diaphragm and its disorders. J Thorac Imaging 1989;4(1):1±18.
Orhan Oyar, M.D., PhD, Associate Professor, was born in Istanbul in 1963. He graduated from Ege University, Faculty of Medicine in 1986. He gained his doctorate from Ege University, Faculty of Medicine, Department of Radiology during 1987±1991. In this period, he worked in the Computed Tomography Division for 1 year and the Magnetic Resonance Imaging Division for 2 years. He led the Thoracic and Abdominal Radiology Group. In 1996, he became an associate professor. Mr. Oyar has over 80 manuscripts published in Turkish and international journals. He is a member of the New York Academy of Sciences, European Federation of Societies for Ultrasound in Medicine and Biology, European Society of North America, American Roentgen Ray Society and the European Congress of Radiology.
Gulgun Kayalioglu, M.D., PhD, was born in Ankara in 1996. She graduated from Ege University, Faculty of Medicine in 1990. After working as a physician in Yozgat between 1990 and 1991, she started her doctorate training at Ege University, Faculty of Medicine, Department of Anatomy. Dr. Kayalioglu ®nished her doctorate in 1994 and is currently working at Ege University. Dr. Kayalioglu worked in Karolinska Institute, Department of Neuroscience, Stockholm for a period of 6 months with postdoctoral fellowship grants from the Turkish Scienti®c Research Association and The Swedish Institute. Dr. Kayalioglu has over 20 manuscripts published in national and international journals.
Ufuk Cagirici, M.D., PhD, was born in Izmir in 1962. He graduated from Ege University, Faculty of Medicine. He started his doctorate at Izmir Chest Diseases and Thoracic Surgery Training Hospital and ®nished his Thoracic surgery doctorate in 1992. He worked as chief assistant during 1992±1996. Mr. Cagirici has been working as a postdoctorate at Ege University, Faculty of Medicine, Department of Thoracic Surgery since 1996. Ufuk Cagirici is one of the founders of the Izmir Thoracic Surgery Society. He is also a member of National Trauma Association and Turkish Cardiothoracic Surgery Association. He is also a member of the Consultative Committee of Izmir Chest Diseases and Thoracic Surgery Training Hospital.
Computerized Medical Imaging and Graphics 22 (1998) 421±423
Diaphragmatic crus lipoma: a case report Orhan Oyar a,*, Gulgun Kayalioglu b, Ufuk Cagirici c a
Department of Diagnostic Radiology, Ege University, 35100, Bornova, Izmir, Turkey b Department of Anatomy, Ege University, 35100, Bornova, Izmir, Turkey c Department of Thoracic Surgery, Ege University, 35100, Bornova, Izmir, Turkey
Received 9 April 1998; received in revised form 24 September 1998; accepted 24 September 1998
Abstract Diaphragmatic crus lipoma is a very rare entity. In this case report, smooth, rounded masses of diaphragmatic lipoma, incidentally observed in a 37-year-old female on routine abdominal computed tomographic scanning is presented. q 1998 Elsevier Science Ltd. All rights reserved. Keywords: Lipoma; Diaphragm; Computed tomography
1. Case report
2. Discussion
During CT evaluation of a 37-year-old female patient suffering from pelvic pain, radiological features of pelvic in¯ammatory disease were observed. In the scans through the upper abdomen, the right diaphragmatic crus was observed as a linear homogeneous solid density, while the left crus showed a different morphology and a different density (Fig. 1). In three to four scans through the level of the left posterior cul de sac, two rounded masses and a band with normal crus density between them were present in the diaphragmatic crus. The masses showed a density measuring about 2100 Houns®eld units (HU) consistent with that of adipose tissue (Fig. 2). The crura on the anterior and posterior sides of the masses had a V-shaped or drinking glass-shaped morphology, con®rming the intrinsic origin of the lesion. When contiguous scans were examined, it was observed that the left diaphragmatic crus acquired its normal thickness, morphology and density in the proximal (Fig. 3) and distal (Fig. 4) parts of the lesion masses. We did not perform ®ne needle aspiration biopsy for con®rmation due to the small dimension of the masses, and high risk of damaging vital organs and tissues. Diagnostic surgical intervention was avoided because the lipoma was very small and the case was asymptomatic and malign degeneration of lipomas has not been reported in the literature.
The diaphragm is a dome-shaped, musculo®brous septum which separates the thoracic from the abdominal cavity. Its peripheral part consists of muscular ®bers which originate from the circumference of the thoracic outlet and converge to be inserted into a central tendon. The muscular ®bers of the diaphragm consist of sternal, costal and lumbar parts. The sternal part arises from two ¯eshy slips from the back of the xiphoid process, the costal part from the inner surface of the cartilages and adjacent portions of the lower six ribs on each side. The lumbar part arises from two aponeurotic ligaments named the medial and lateral lumbocostal ligaments from the lumbar vertebrae by two crura. Two crura join anteriorly in front of the spine by means of the median arcuate ligament in front of the abdominal aorta and the vertebral column [1,2]. Diaphragmatic lipomas are encapsulated, soft fatty tumors frequently occurring in obese patients. They are equally common in men and women, reported twice as often on the left side, mostly in a posterolateral location [3,4] and may occasionaly be bilateral [5]. Diaphragmatic lipomas are either sessile or pedunculated and anchored to the diaphragm or hourglass-shaped with an isthmus through the diaphragm and an extrathoracic extension [6]. Sessile lipomas are believed to develop from subpleural mature fatty tissue whereas hourglass-shaped lipomas develop from embryonally undifferentiated tissue [6]. Although there are very few cases reported, diaphragmatic lipomas are probably more common. Due to their stable and usually asymptomatic nature, they are
* Corresponding author at: 87 sok. Iyriboz Apt. No. 4 D, 14, 35040, Bornova, Izmir, Turkey. fax: 1 90-232-3390002.
0895-6111/99/$ - see front matter q 1998 Elsevier Science Ltd. All rights reserved. PII: S 0895-611 1(98)00053-6
422
O. Oyar et al. / Computerized Medical Imaging and Graphics 22 (1998) 421±423
Fig. 1. CT scan passing from the upper abdomen, showing varying density of the left diaphragmatic crus.
Fig. 3. CT scan passing from a section proximal to the diaphragmatic lipoma, showing normal morphology of the left diaphragmatic crus.
incidentally discovered mostly during diagnostic visualization techniques done for other different symptoms of the patients or at autopsy [7]. It has been reported that diaphragmatic lipomas may occasionally cause dry cough and thoracic pain [6]. Although diaphragmatic lipomas usually remain stable in size and have not been reported to degenerate into liposarcoma, they should be followed up in time with CT. Visualization of diaphragmatic crura is very limited with plain radiography. Only the inferior extents of diaphragmatic crura can be distinguished due to the contrast of retroperitoneal adipose tissue. Routine thoracoabdominal CT scanning is preferred to all other techniques in visualization of the crura because it allows the visualization of crura morphology and evaluation of their density. With the widespread usage of CT, diaphragmatic pathologies omitted in plain radiography can now be detected. This led to an increase in diagnosis of diaphragmatic lipomas and asymptomatic hernias and especially Bochdalek hernias.
Castillo and Shirkhoda [8] reported ®ve cases of diaphragmatic lipomas with CT. Ferguson and Westcott [7] also reported a case of diaphragmatic lipoma with CT, they con®rmed their diagnosis with postmortem examination. Diaphragmatic lipomas are frequently mistaken for hernias, especially Bochdalek hernias, and localized eventrations. Eventrations usually retain the general con®guration of the diaphragm, in contrast with the spherical or ovoid shape of lipomas [7]. Most of the Bochdalek hernias in adults contain fat, so they may erroneously be interpreted as diaphragmatic lipoma. Differential diagnosis of Bochdalek hernias from diaphragmatic lipoma is one of the most important dif®culties in diaphragmatic imaging. Bochdalek hernias have four characteristics de®ned with CT:
Fig. 2. CT scan showing a diaphragmatic lipoma as hypodense masses in the left diaphragmatic crus.
Fig. 4. CT scan passing from a section distal to the diaphragmatic lipoma, showing normal morphology of the left diaphragmatic crus.
1. Bochdalek hernias are round±oval masses, adjacent to the thoracic surface of the diaphragm, showing a density of 2130 to 2120 HU;
O. Oyar et al. / Computerized Medical Imaging and Graphics 22 (1998) 421±423
2. they are located in the posteromedial aspect of the hemidiaphragm; 3. there is a discontinuity in the muscular tissue of the diaphragm and a V-shaped con®guration is present; 4. the density of the diaphragmatic defect continues supradiaphragmatically and subdiaphragmatically [9±12]. In this case, a V-shaped con®guration was observed in the ventral and dorsal part of the left diaphragmatic crus, but no discontinuity was de®ned in the diaphragm. A very thin line of diaphragmatic density surrounding the lesion could be observed. The left diaphragmatic crus was returning to its normal con®guration and density here. The presence of nodular hypodense masses instead of a solid homogeneous mass con®rms that the case is an intrinsic pathology of the diaphragm. We propose that the V-shaped con®guration in the adjacent diaphragm musculature is not speci®c for Bochdalek hernias and any intrinsic pathology of the diaphragm having a different density can show a similar con®guration in diaphragmatic crura. Most important of all, the discontinuity of adipose tissue density in cranial and caudal parts, and continuity of the diaphragm caudally especially differentiates lipoma from retroperitoneal adipose tissue. Based on these facts, it is suggested that the presence of these rounded masses in left diaphragmatic crus is concordant with asymptomatic incidental diaphragmatic crus lipoma rather than a small Bochdalek hernia. 3. Summary During CT evaluation of a 37-year-old female patient suffering from pelvic pain, radiological features of pelvic in¯ammatory disease were observed. In the scans through the upper abdomen, the right diaphragmatic crus was observed as a linear homogenous solid density, while the left crus showed a different morphology and a different density. In three to four scans through the level of the left posterior cul de sac, two rounded masses were observed. The masses showed a density of about 2100 HU, consistent with that of adipose tissue and a band with normal crus density between them was present. The crura on the anterior and posterior sides of the masses had a V-shaped or drinking glass-shaped morphology. Fine needle aspiration biopsy and diagnostic surgical intervention biopsy for con®rmation was avoided due to the small dimension of the masses, high risk of damaging vital organs and tissues and benign nature of diaphragmatic lipoma.
References [1] Gray H. Gray's anatomy, 37th ed. In: Williams P, Warwick R., editors. London: Churchill Livingstone, 1989. [2] Silverman PM, Cooper C, Zeman RK. Lateral arcuate ligaments of the diaphragm: Anatomic variations at abdominal CT. Radiology 1992;185(1):105±108.
423
[3] Dalquen P. Lipoma of the diaphragm: Malformation or hernia?. Thoraxchir Vask Chir 1972;20(2):112±115. [4] Wiener MF, Chou WH. Primary tumors of the diaphragm. Arch Surg 1965;90(2):143±152. [5] Tihansky DP, Lopez GM. Bilateral lipomas of the diaphragm. NY State J Med 1988;88(3):151±152. [6] Kalen NA. Lipoma of the diaphragm. Scand J Resp Dis 1970;51(1):28±32. [7] Ferguson DD, Westcott JL. Lipoma of the diaphragm: Report of a case. Radiology 1976;118(3):527±528. [8] Castillo M, Shirkhoda A. Computed tomography of diaphragmatic lipoma. J Comput Tomogr 1985;9(2):167±170. [9] De Martini WJ, House AJS. Partial Bochdalek's herniation: computerized tomographic evaluation. Chest 1980;77(5):702±704. [10] Gale ME. Bochdalek hernia: prevalance and CT characteristics. Radiology 1985;156(2):449±452. [11] Shin MS, Mulligan SA, Baxley WA, Ho KJ. Bochdalek hernia of diaphragm in the adult: Diagnosis by computed tomography. Chest 1987;92(6):1098±1101. [12] Tarver RD, Conces Jr DJ, Cory DA, Vix VA. Imaging the diaphragm and its disorders. J Thorac Imaging 1989;4(1):1±18.
Orhan Oyar, M.D., PhD, Associate Professor, was born in Istanbul in 1963. He graduated from Ege University, Faculty of Medicine in 1986. He gained his doctorate from Ege University, Faculty of Medicine, Department of Radiology during 1987±1991. In this period, he worked in the Computed Tomography Division for 1 year and the Magnetic Resonance Imaging Division for 2 years. He led the Thoracic and Abdominal Radiology Group. In 1996, he became an associate professor. Mr. Oyar has over 80 manuscripts published in Turkish and international journals. He is a member of the New York Academy of Sciences, European Federation of Societies for Ultrasound in Medicine and Biology, European Society of North America, American Roentgen Ray Society and the European Congress of Radiology.
Gulgun Kayalioglu, M.D., PhD, was born in Ankara in 1996. She graduated from Ege University, Faculty of Medicine in 1990. After working as a physician in Yozgat between 1990 and 1991, she started her doctorate training at Ege University, Faculty of Medicine, Department of Anatomy. Dr. Kayalioglu ®nished her doctorate in 1994 and is currently working at Ege University. Dr. Kayalioglu worked in Karolinska Institute, Department of Neuroscience, Stockholm for a period of 6 months with postdoctoral fellowship grants from the Turkish Scienti®c Research Association and The Swedish Institute. Dr. Kayalioglu has over 20 manuscripts published in national and international journals.
Ufuk Cagirici, M.D., PhD, was born in Izmir in 1962. He graduated from Ege University, Faculty of Medicine. He started his doctorate at Izmir Chest Diseases and Thoracic Surgery Training Hospital and ®nished his Thoracic surgery doctorate in 1992. He worked as chief assistant during 1992±1996. Mr. Cagirici has been working as a postdoctorate at Ege University, Faculty of Medicine, Department of Thoracic Surgery since 1996. Ufuk Cagirici is one of the founders of the Izmir Thoracic Surgery Society. He is also a member of National Trauma Association and Turkish Cardiothoracic Surgery Association. He is also a member of the Consultative Committee of Izmir Chest Diseases and Thoracic Surgery Training Hospital.