Clinical Radiology (1992) 45, 203 205
Case Report: Imaging of Bile Duct Hamartomas C. M A R T I N O L I , G. C I T T A D I N I , Jr, G. A. R O L L A N D I and R. C O N Z I
Institute of Radiology- "R", University of Genoa, Genova, Italy A rare case of multiple bile duct hamartomas of the liver has been evaluated with ultrasound (US), computed tomography (CT), magnetic resonance imaging (MRI) and digital subtraction angiography (DSA). The CT and angiographic features of the hamartomas described here differ significantly from previously reported cases. In addition, the MR appearance of these tumours is reported for the first time. Martinoli, C., Cittadini, G. Jr, Rollandi, G.A. & Conzi, R. (1992). Clinical Radiology 45, 203 205. Case Report: Imaging of Bile Duct Hamartomas
Bile duct h a m a r t o m a s (BDH) of the liver (also termed von Meyenburg complexes) have been considered a rare incidental finding which can be confused with metastatic disease (Mixter and Mixter, 1953; Chung, 1970). The diagnostic characteristics of bile duct hamartomas have not been well documented because only a few cases have been reported previously; all of these were examined with only one (McLoughlin and Phillips, 1975; Cooke and Cooke, 1987; Tan et al., 1989) or two imaging modalities (Eisenberg et al., 1986). This work reports the case of a patient affected by multiple B D H of the liver associated to pancreatic cysts. The findings on ultrasound (US), computed tomography (CT), magnetic resonance imaging (MRI) and digital subtraction angiography (DSA) are described.
examination the diagnosis of multiple hepatic B D H and chronic cystic pancreatitis was made, The post-operative course was uneventful and the patient remains well 6 months later.
CASE REPORT A 23-year-old female presented with recent onset of pain in the pancreaticoduodenal region. Biochemistry and liver function tests showed only an increased value of serum yGT (364 U/litre). US examination demonstrated a 3.5 × 2 cm cystic mass in the head of the pancreas, surrounded by an inhomogeneous, hypoechoic parenchymal area. The main pancreatic duct was not ectatic. The liver was characterized by well defined multiple rounded homogeneously hypoechoic nodular lesions randomly scattered throughout the parenchyma (Fig. la). Nodule size ranged from 0.7 to 3 cm approximately. The gallbladder and biliary tree were normal. US-Doppler examination showed regular flow within portal, eoeliac and superior mesenteric vessels. Neither lymph node enlargement nor peritoneal fluid were demonstrated. In order to vcrify the hypothesis of pancreatic cystic cancer metastatized to the liver, CT, M R I and selective coeliac and superior mesenteric D S A were performed. CT confirmed the cystic appearance of the pancreatic mass and imaged liver nodules as multiple, rounded, well outlined low attenuation lesions. After i.v. administration of contrast medium, the hepatic nodules became rapidly and homogeneously hyperdense to the surrounding normal parenchyma (Fig. lb). No peripheral, ring-like contrast enhancement of the nodules was observed. M R I characterized the hepatic nodules as hypointense on Tl-weighted spin-echo sequences (Fig. 2a) and hyperintense on T2-weighted ones (Fig. 2b). D y n a m i c M R I with dimeglumine gadopentetate (Gd-DTPA) displayed a slow perfusion pattern in the nodules, analogous to the contrast-enhanced CT (Fig. 2c). D S A showed multiple nodules of abnormal vascularity scattered in the liver parenchyma (Fig. 3a) in which contrast medium persisted through the venous phase (Fig. 3b). No vascular abnormalities were detected in the pancreatic head. After US-guided fine needle biopsies of the pancreatic mass and of one of the hepatic nodules were performed with non-diagnostic cytologic results, the patient underwent laparotomy and surgical resection of some hepatic lesions for histological examination. In addition, per-operative biopsies of the pancreatic head were performed. On histological Correspondence to: Dr Carlo Martinoli, Institute of Radiology "R", University of Genoa, Viale Benedetto XV, 10, 1-16132, Genova, Italy.
(a)
(b) Fig. I US (a) and dynamic CT (b) scan show representative B D H nodules. On the US image the nodule is characterized by posterior acoustic enhancement. On the CT image the lesion enhances homogeneously.
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CLINICAL RADIOLOGY
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(a)
(b)
(b) (c) Fig. 2 - M R imaging of hepatic BDH. (a) Tl-weighted SE image (350/ 20). (b) T2-weighted SE image (1800/120). (c) Gd-enhanced TIweighted SE image (350/20). BDH are hypointense on T1 and brightly hyperintense on T2-weighted images. Dynamic MRI shows regular Gdenhancement within lesion, in that similar to contrast-enhanced CT.
DISCUSSION Originally described by von Meyenburg (von Meyenburg, 1918), hepatic BDH is a rare disorder (Chung, 1970) consisting of discrete greyish-white nodular lesions widely scattered throughout liver parenchyma, usually ranging between 0.1 and 0.5 cm in size (Chung, 1970; Eisenberg et al., 1986; Tan et al., 1989), but occasionally larger. In one recently reported case (Bornfors, 1984)
Fig. 3 Digital subtrfiction angiography. (a) Arterial phase; (b) venous phase. Tumour stain of the BDH nodules persists throughout the venous phase as delayed wash-out. No vascular findings typical of malignant neoplasms are recognizable.
BDH measured up to 3 cm. It is generally accepted that BDH represent a developmental defect rather than a true neoplasm and may be seen in isolation or associated with other congenital disorders such as hepatic fibrosis (MacMahon, 1929), polycystic liver and kidney disease (von Meyenburg, 1918; MacMahon, 1929; Chung, 1970) and pancreatic cysts (MacMahon, 1929). Patients with BDH are usually asymptomatic. However, these lesions are important to recognize because they may be confused with metastatic cancer. A few cases of association with cholangiocarcinoma have been reported (Bornfors, 1984; Dekker et al., 1989). On US, BDH exhibited unusual but non-specific features: (i) solid, homogeneously hypoechoic pattern; (ii)
IMAGING OF BILE DUCT HAMARTOMAS thin, well defined outlines without lateral acoustic shadowing; and (iii) posterior acoustic enhancement. Both hypoechoic (Eisenberg e t al., 1986) and hyperechoic (Tan et al., 1989) B D H have been described elsewhere, illustrating the variable echogenic pattern o f these lesions. To our knowledge, the M R appearance o f B D H has not been reported previously. On M R I , B D H showed relaxation parameters different from those of normal hepatic parenchyma. Whereas on Tl-weighted images B D H were slightly hypointense, heavily T2-weighted spin-echo sequences with echo times greater than 120 ms effectively displayed the long T2 bright signal typical o f lesions containing slowly flowing blood. D y n a m i c M R imaging with G d - D T P A confirmed the h o m o g e n e o u s and slow perfusion pattern o f B D H . The pattern of vascularity o f the lesions seen in our patient, as assessed by dynamic CT and angiography, is different f r o m that reported previously (McLoughlin and Phillips, 1975; C o o k e and Cooke, 1987). CT showed regular and uniform contrast enhancement o f the lesions unlike the case reported by Cooke and C o o k e (1987). In addition, D S A did not demonstrate the grape-like pattern of small rings 2-3 m m in diameter reported by M c L o u g h lin and Phillips (1975). In conclusion, B D H have non-specific, variable imaging appearances. In the case presented in this report, B D H seem to share most imaging features with other benign liver tumours. These features are: (i) regular outlines; (ii) h o m o g e n e o u s parenchymal texture on US, CT and M R I ; (iii) uniform contrast enhancement on CT and M R I ; (iv) absence o f vascular signs o f malignancy on DSA. These lesions can usually be differentiated from h a e m a n g i o m a s on the basis o f their US appearance but there are no specific criteria with which to distinguish
205
them from focal nodular hyperplasia or liver cell adenomas. Both these latter lesions are usually solitary and m a y exhibit typical findings such as a central scar or dystrophic changes respectively. In addition, focal n o d u l a r hyperplasia and liver a d e n o m a are in general characterized by M R I signal intensity and C T attenuation values quite similar to those o f normal liver. However, neither o f these conditions can be excluded in the absence o f the above characteristic M R I and C T findings.
REFERENCES
Bornfors, M (1984). The development of cholangiocarcinoma from multiple bile-duct adenomas. Acta Pathologica, Microbiologica, et Immunologiea Scandinavica, 2, 285 289, Chung, EB (1970). Multiple bile duct hamartomas. Cancer, 26,287 296. Cooke, JC & Cooke, DAP (1987). The appearances of multiple biliary hamartomas of the liver (von Meyenberg complexes) on computed tomography. Clinical Radiology, 38, 101 102. Dekker, A, Ten Kate, FJW & Terpstra, OT (1989). Cholangiocarcinoma associated with multiple bile duct hamartomas of the liver. Digestive Diseases and Sciences, 34, 952-958. Eisenberg, D, Hurwitz, L & Yu, AC (1986). CT and sonography of multiple bile-duct hamartomas simulating malignant liver disease (case report). American Journal o f Roentgenology, 147, 279-280. MacMahon, HE (1929). Congenital anomalies of the liver. American Journal of Pathology, 5, 499 507. McLoughlin, MJ & Phillips, MJ (1975). Angiographic findings in mulhple bile duct hamartomas of the liver. Radiology, 116, 41 43. Mixter, CG & Mixter, CG Jr (1953). Liver nodules encountered at laparotomy: significance and treatment. Annals of Surgery, 138, 230 239. Tan, A, Shen, JF & Hecht, AH (1989). Sonogram of multiple bile duct hamartomas. JournalofClinical Ultrasound, 17, 667 669. von Meyenburg, H (1918). Uber die Cystenleber. Beitrage zur Pathologic und Anatomie, 64, 477-532.
Case Report: Imaging of Bile Duct Hamartomas C. M A R T I N O L I , G. C I T T A D I N I , Jr, G. A. R O L L A N D I and R. C O N Z I
Institute of Radiology- "R", University of Genoa, Genova, Italy A rare case of multiple bile duct hamartomas of the liver has been evaluated with ultrasound (US), computed tomography (CT), magnetic resonance imaging (MRI) and digital subtraction angiography (DSA). The CT and angiographic features of the hamartomas described here differ significantly from previously reported cases. In addition, the MR appearance of these tumours is reported for the first time. Martinoli, C., Cittadini, G. Jr, Rollandi, G.A. & Conzi, R. (1992). Clinical Radiology 45, 203 205. Case Report: Imaging of Bile Duct Hamartomas
Bile duct h a m a r t o m a s (BDH) of the liver (also termed von Meyenburg complexes) have been considered a rare incidental finding which can be confused with metastatic disease (Mixter and Mixter, 1953; Chung, 1970). The diagnostic characteristics of bile duct hamartomas have not been well documented because only a few cases have been reported previously; all of these were examined with only one (McLoughlin and Phillips, 1975; Cooke and Cooke, 1987; Tan et al., 1989) or two imaging modalities (Eisenberg et al., 1986). This work reports the case of a patient affected by multiple B D H of the liver associated to pancreatic cysts. The findings on ultrasound (US), computed tomography (CT), magnetic resonance imaging (MRI) and digital subtraction angiography (DSA) are described.
examination the diagnosis of multiple hepatic B D H and chronic cystic pancreatitis was made, The post-operative course was uneventful and the patient remains well 6 months later.
CASE REPORT A 23-year-old female presented with recent onset of pain in the pancreaticoduodenal region. Biochemistry and liver function tests showed only an increased value of serum yGT (364 U/litre). US examination demonstrated a 3.5 × 2 cm cystic mass in the head of the pancreas, surrounded by an inhomogeneous, hypoechoic parenchymal area. The main pancreatic duct was not ectatic. The liver was characterized by well defined multiple rounded homogeneously hypoechoic nodular lesions randomly scattered throughout the parenchyma (Fig. la). Nodule size ranged from 0.7 to 3 cm approximately. The gallbladder and biliary tree were normal. US-Doppler examination showed regular flow within portal, eoeliac and superior mesenteric vessels. Neither lymph node enlargement nor peritoneal fluid were demonstrated. In order to vcrify the hypothesis of pancreatic cystic cancer metastatized to the liver, CT, M R I and selective coeliac and superior mesenteric D S A were performed. CT confirmed the cystic appearance of the pancreatic mass and imaged liver nodules as multiple, rounded, well outlined low attenuation lesions. After i.v. administration of contrast medium, the hepatic nodules became rapidly and homogeneously hyperdense to the surrounding normal parenchyma (Fig. lb). No peripheral, ring-like contrast enhancement of the nodules was observed. M R I characterized the hepatic nodules as hypointense on Tl-weighted spin-echo sequences (Fig. 2a) and hyperintense on T2-weighted ones (Fig. 2b). D y n a m i c M R I with dimeglumine gadopentetate (Gd-DTPA) displayed a slow perfusion pattern in the nodules, analogous to the contrast-enhanced CT (Fig. 2c). D S A showed multiple nodules of abnormal vascularity scattered in the liver parenchyma (Fig. 3a) in which contrast medium persisted through the venous phase (Fig. 3b). No vascular abnormalities were detected in the pancreatic head. After US-guided fine needle biopsies of the pancreatic mass and of one of the hepatic nodules were performed with non-diagnostic cytologic results, the patient underwent laparotomy and surgical resection of some hepatic lesions for histological examination. In addition, per-operative biopsies of the pancreatic head were performed. On histological Correspondence to: Dr Carlo Martinoli, Institute of Radiology "R", University of Genoa, Viale Benedetto XV, 10, 1-16132, Genova, Italy.
(a)
(b) Fig. I US (a) and dynamic CT (b) scan show representative B D H nodules. On the US image the nodule is characterized by posterior acoustic enhancement. On the CT image the lesion enhances homogeneously.
204
CLINICAL RADIOLOGY
~)
(a)
(b)
(b) (c) Fig. 2 - M R imaging of hepatic BDH. (a) Tl-weighted SE image (350/ 20). (b) T2-weighted SE image (1800/120). (c) Gd-enhanced TIweighted SE image (350/20). BDH are hypointense on T1 and brightly hyperintense on T2-weighted images. Dynamic MRI shows regular Gdenhancement within lesion, in that similar to contrast-enhanced CT.
DISCUSSION Originally described by von Meyenburg (von Meyenburg, 1918), hepatic BDH is a rare disorder (Chung, 1970) consisting of discrete greyish-white nodular lesions widely scattered throughout liver parenchyma, usually ranging between 0.1 and 0.5 cm in size (Chung, 1970; Eisenberg et al., 1986; Tan et al., 1989), but occasionally larger. In one recently reported case (Bornfors, 1984)
Fig. 3 Digital subtrfiction angiography. (a) Arterial phase; (b) venous phase. Tumour stain of the BDH nodules persists throughout the venous phase as delayed wash-out. No vascular findings typical of malignant neoplasms are recognizable.
BDH measured up to 3 cm. It is generally accepted that BDH represent a developmental defect rather than a true neoplasm and may be seen in isolation or associated with other congenital disorders such as hepatic fibrosis (MacMahon, 1929), polycystic liver and kidney disease (von Meyenburg, 1918; MacMahon, 1929; Chung, 1970) and pancreatic cysts (MacMahon, 1929). Patients with BDH are usually asymptomatic. However, these lesions are important to recognize because they may be confused with metastatic cancer. A few cases of association with cholangiocarcinoma have been reported (Bornfors, 1984; Dekker et al., 1989). On US, BDH exhibited unusual but non-specific features: (i) solid, homogeneously hypoechoic pattern; (ii)
IMAGING OF BILE DUCT HAMARTOMAS thin, well defined outlines without lateral acoustic shadowing; and (iii) posterior acoustic enhancement. Both hypoechoic (Eisenberg e t al., 1986) and hyperechoic (Tan et al., 1989) B D H have been described elsewhere, illustrating the variable echogenic pattern o f these lesions. To our knowledge, the M R appearance o f B D H has not been reported previously. On M R I , B D H showed relaxation parameters different from those of normal hepatic parenchyma. Whereas on Tl-weighted images B D H were slightly hypointense, heavily T2-weighted spin-echo sequences with echo times greater than 120 ms effectively displayed the long T2 bright signal typical o f lesions containing slowly flowing blood. D y n a m i c M R imaging with G d - D T P A confirmed the h o m o g e n e o u s and slow perfusion pattern o f B D H . The pattern of vascularity o f the lesions seen in our patient, as assessed by dynamic CT and angiography, is different f r o m that reported previously (McLoughlin and Phillips, 1975; C o o k e and Cooke, 1987). CT showed regular and uniform contrast enhancement o f the lesions unlike the case reported by Cooke and C o o k e (1987). In addition, D S A did not demonstrate the grape-like pattern of small rings 2-3 m m in diameter reported by M c L o u g h lin and Phillips (1975). In conclusion, B D H have non-specific, variable imaging appearances. In the case presented in this report, B D H seem to share most imaging features with other benign liver tumours. These features are: (i) regular outlines; (ii) h o m o g e n e o u s parenchymal texture on US, CT and M R I ; (iii) uniform contrast enhancement on CT and M R I ; (iv) absence o f vascular signs o f malignancy on DSA. These lesions can usually be differentiated from h a e m a n g i o m a s on the basis o f their US appearance but there are no specific criteria with which to distinguish
205
them from focal nodular hyperplasia or liver cell adenomas. Both these latter lesions are usually solitary and m a y exhibit typical findings such as a central scar or dystrophic changes respectively. In addition, focal n o d u l a r hyperplasia and liver a d e n o m a are in general characterized by M R I signal intensity and C T attenuation values quite similar to those o f normal liver. However, neither o f these conditions can be excluded in the absence o f the above characteristic M R I and C T findings.
REFERENCES
Bornfors, M (1984). The development of cholangiocarcinoma from multiple bile-duct adenomas. Acta Pathologica, Microbiologica, et Immunologiea Scandinavica, 2, 285 289, Chung, EB (1970). Multiple bile duct hamartomas. Cancer, 26,287 296. Cooke, JC & Cooke, DAP (1987). The appearances of multiple biliary hamartomas of the liver (von Meyenberg complexes) on computed tomography. Clinical Radiology, 38, 101 102. Dekker, A, Ten Kate, FJW & Terpstra, OT (1989). Cholangiocarcinoma associated with multiple bile duct hamartomas of the liver. Digestive Diseases and Sciences, 34, 952-958. Eisenberg, D, Hurwitz, L & Yu, AC (1986). CT and sonography of multiple bile-duct hamartomas simulating malignant liver disease (case report). American Journal o f Roentgenology, 147, 279-280. MacMahon, HE (1929). Congenital anomalies of the liver. American Journal of Pathology, 5, 499 507. McLoughlin, MJ & Phillips, MJ (1975). Angiographic findings in mulhple bile duct hamartomas of the liver. Radiology, 116, 41 43. Mixter, CG & Mixter, CG Jr (1953). Liver nodules encountered at laparotomy: significance and treatment. Annals of Surgery, 138, 230 239. Tan, A, Shen, JF & Hecht, AH (1989). Sonogram of multiple bile duct hamartomas. JournalofClinical Ultrasound, 17, 667 669. von Meyenburg, H (1918). Uber die Cystenleber. Beitrage zur Pathologic und Anatomie, 64, 477-532.
