Mesenchymal hamartoma of the liver in an adult: radiologic diagnosis

A case of mesenchymal hamartoma of the liver in a 30-year-old female is reported. Ultrasonography, computed tomography, and hepatic angiography demonstrated the presence of a large, mixed cystic and solid mass within the liver, suggesting the diagnosis of a mesenchymal hamartoma. At surgery, the tumor proved to be unresectable.     

Hamartome mésenchymateux du foie chez l’enfant : une nouvelle observation

Due to their rarity in childhood, tumors of the liver can be difficult to diagnose and manage. Mesenchymal hamartoma is the second most frequent benign liver tumor in children, and yet still a rare entity, poorly understood.Typically, it presents as a rapidly enlarging, painless, abdominal mass in children younger than two years. Spontaneous regression or occasional malignant degeneration into undifferentiated embryonal sarcoma can rarely occur. Here, we report a case of a mesenchymal hamartoma of the liver in a 18 month-old child. The imaging features were suggestive of the diagnostic and confirmed by the pathological examination of the surgical specimen.We discuss the clinicopathological, imaging, and histological features of this tumor through a review of the literature.     

Giant mesenchymal hamartoma of the liver in an adult

We report a case of hepatic mesenchymal hamartoma in an adult; this condition is extremely rare, with only 15 cases having been reported in the English-language literature worldwide. The patient was a 36-year-old woman who was seen at her local hospital for upper abdominal distension. A giant multilocular cystic tumor, which had almost entirely replaced the normal parenchyma of the right lobe of the liver, was diagnosed. She was referred to our hospital, where, with a diagnosis of biliary cystadenoma, the tumor was successfully removed by right hemihepatectomy. After an uneventful postoperative course, the patient was discharged from our hospital. On histological examination, the tumor consisted of numerous cystic lesions without epithelial lining cells; hepatocytes, bile duct, and vascular components, without either lobular structure or atypia, were observed in the pseudocyst wall, leading to a diagnosis of hepatic mesenchymal hamartoma. There have been a few previously reported cases of multifocal hepatic mesenchymal hamartoma reappearing in the remaining liver after hepatectomy, although these cases are considered to be extremely rare. Therefore, periodic follow-up will be necessary for the patient.     

Adult mesenchymal hamartoma of the liver mimicking bile duct cystadenoma

We report a rare case of mesenchymal hamartoma in the cirrhotic liver of a 52-year-old Japanese male. The tumor, 3.5 cm in diameter, contained a cystic lesion and was located in the lateral segment. Bile duct cystadenoma was considered most likely preoperatively because of the patient's age and the normal levels of tumor markers. However, since malignancy of the lesion could not be ruled out by preoperative imaging diagnosis, lateral segmentectomy was performed. Histological examination led to a diagnosis of mesenchymal hamartoma, since the lesion consiste of a multilocular abnormal bile duct accompanied by abundant myxomatous or loose collagen.     

Mesenchymal hamartoma of liver： Magnetic resonance imaging and histopathologic correlation

AIM: To describe the imaging features of hepatic mesenchymal hamartoma with emphasis on magnetic resonance imaging(MRI) compared to histopathologic results. METHODS: Spin-echo sequence(SE),fast spin-echo sequence(FSE) were detected in 12 children(7 males,5 females) with mesenchymal hamartoma of the liver(MHL), aged 1.2 months to 12 years,( mean age, 6.3 years) by axial, saggital, coronary plain imaging with an Elscint 2.0T MR equipment. Their main symptoms were abdominal mass(5 cases), enlarged liver(8 cases), abdominal pain(1 case) and anemia(2 cases), and negative alpha-fetoprotein. Dynamic enhancement examination was added in 2 cases. RESULTS: Six cases had single mass type of MHL, in which 3 cases had solid masses showing slight lowsignal-intensity in T1WI, and irregular high-signalintensity in T2WI, 1 case had a cystic-solid mixed mass showing several border-clear cysts in a solid mass, 2 cases had cystic masses with multi-septa. Five cases had diffuse and multifocal lesions type of MHL with its signal intensity being similar to that of the solid mass. One case had a combined diffuse and single cystic mass. In the early dynamic enhancement examination, the lesions were slightly circum-enhanced, and the center was enhanced in the later scan images. Inner hepatic vessels were compressed in 5 cases, vena cava and abdominal aortae were compressed in 3 cases. Pathological findings included fiber hyperplasia, hyaline degeneration, biliary duct hyperplasia, lobule-like array. CONCLUSION: MR imaging is a better way to differentiate and diagnose MHL. MHL may be recognized by its characteristic occurrence in infancy and MR imaging features.     

Clinical Presentation and Anatopathologic Finding of a Hepatic Vascular Hamartoma: a Case Report.

HVH (hepatic vascular hamartoma) is a tumor like malformation arising from the vascular tissue of the liver. HVH has been previously reported in animals and presents distintive features from the most frequent benign tumor like malformation of the liver, the hepatic mesenchymal hamartoma (HMH). Herein we report a case of HVH localized in hepatic segment 4b, involving the gastro hepatic ligament, successfully treated with total excision. We describe the anatomo-pathologic findings focusing on the clinical and radiological presentation, the intraoperative characteristics and the differential diagnosis.     

Mesenchymal hamartoma of the liver.

The case of a 19 yr-old female with abdominal pain, jaundice, and hepatomegaly is reported. A large mass replacing the left hepatic lobe, detected by scintigraphic and angiographic studies and also by means of ultrasound and transhepatic radio-opaque filling, proved to be cystic. A left hepatic lobectomy was performed. Pathologic examination revealed a mesenchymal hamartoma, a rather rare event in view of the patient's age. Prompt recovery followed surgery, and the patient is well and symptomless 1 yr after operation.     

Mesenchymal hamartoma of the liver in adulthood: immunohistochemical profiles, clinical and histopathological features in two patients

Mesenchymal hamartoma is an uncommon cystic mass of the liver which occurs primarily in children. There are a few reports of its occurrence in adulthood. Here, we present two cases in female patients, 54 and 51 years old. Radiological examinations in both patients showed multiple cystic lesions in the liver. Surgically, total cystectomy was performed in the first patient, while an unroofing procedure was done in the second patient (due to misdiagnosis of the lesion as a simple cyst of the liver). On microscopic examinations of the lesion in each patient, a multilocular cyst was observed, lined by flattened epithelium and surrounded by a mesenchymal component composed of mature connective tissue, arterial and venous vascular structures, peripheral nerve bundles, and ductal structures. An immunohistochemical panel consisting of desmin, smooth-muscle actin, S-100, vimentin, CD34, carcinoembryonic antigen, pancytokeratin, cytokeratin 7, cytokeratin 8, cytokeratin 17, cytokeratin 18, cytokeratin 19, and cytokeratin 20 was applied to paraffin sections. Immunoreactivity for cytokeratin 7 and cytokeratin 19 was observed in cystic epithelium and ductal structures. Focal and patchy desmin immunoreactivity was observed in connective tissue. S-100 was positive only in peripheral nerve bundles. In conclusion, mesenchymal hamartoma of the liver in adulthood is a localized tumoral abnormality that precedes birth, and which has delayed clinical presentation. These lesions seems to be related to a maturation process. During this period of maturation, immature edematous stroma rich in mucopolysaccharides may convert to mature paucicellular hyalinized connective tissue. This maturation process may be also related to loss of premalignant potential of these tumors.     

Mesenchymal cystic hamartoma of the lung: A case report

Rationale:Mesenchymal cystic pulmonary hamartoma is a rare type of hamartoma that has been reported in all cases in the literature. Most patients were reported to have spontaneous pneumothorax and were treated by surgery, and finally confirmed to be caused by rupture of the cystic hamartoma. Here, we report a case of mesenchymal cystic pulmonary hamartoma detected using computed tomography (CT) during a health check-up without obvious symptoms.Patient concerns:A 60-year-old woman was detected using CT during her health check-up. She was a non-smoker and had no symptoms or history of specific diseases.Diagnosis:The final pathological examination confirmed that the lesion was a mesenchymal cystic hamartoma of the lung.Interventions:A uniportal video-assisted thoracic surgery wedge resection was performed for biopsy.Outcomes:The patient recovered smoothly and was discharged on postoperative day 3.Lessons:For cystic pulmonary hamartoma, it is usually difficult to make a correct diagnosis using CT imaging. A chest magnetic resonance imaging examination may be helpful for differentiation diagnosis before video-assisted thoracic surgery biopsy.     

Hepatic tumors in children

Although they account for only 1% to 4% of solid tumors in children, hepatic tumors and pseudotumors offer a diagnostic challenge to the clinician seeing only an occasional case. Metastatic lesions such as neuroblastoma, Wilms' tumor, and lymphoma are the most common neoplasm seen in the liver, but 10 distinct primary tumors and pseudotumors of the liver occur with some regularity, and a few others may be seen rarely, including leiomyosarcoma, rhabdoid tumor, and endodermal sinus tumor. Five of these neoplasms--hepatoblastoma, infantile hemangio-endothelioma, mesenchymal hamartoma, undifferentiated embryonal sarcoma, and embryonal rhabdomyosarcoma of the biliary tree--occur only in children and are the major focus of the article.     

Polypoid hamartoma of the jejunum

The authors report an unusual case of jejunal mesenchymal hamartoma which presented as a bleeding pedunculated polyp in a 67-year-old woman. The lesion was detected by enteroclysis and resected after localization by intraoperative endoscopy.     

Malignant liver tumors

Primary malignant liver tumors can arise from different components of the liver, such as hepatocytes, bile duct epithelium, neuroendocrine cells, and mesenchymal cells. A specific diagnosis frequently can be suggested from imaging studies, but biopsy remains the gold standard for definitive diagnosis of liver tumors. Clinical history of chronic liver disease, known risk factors, or other diseases are of great importance. Patient's age is also an important discriminating feature because several tumors such as hepatoblastoma, mesenchymal hamartoma, and infantile hemangioendothelioma, are found predominantly in pediatric populations, whereas cholangiocarcinoma and hepatocellular carcinoma are rare in pediatric populations.     

Ileal angiomyolipoma manifested by small intestinal intussusception

Angiomyolipomas （AMLs）, a form of benign mesenchymal hamartoma, arise primarily in the kidneys of patients with or without tuberous sclerosis. Extra-renal AMLs are very rare and are most commonly found in the liver. AMLs of the small intestine are exceedingly rare. Here, a case of a 28-year-old man, who presented with ileal intussusception caused by ileal AML is reported. The clinicopathological and immunohistochemical findings of ileal AMLs are discussed and the literature on small intestinal AMLs is reviewed.     

Hepatic angiomyolipoma associated with splenic hamartoma

A 52-year-old woman was admitted to our hospital with thrombophlebitis of the internal jugular vein. Abdominal ultrasonography demonstrated a high echogenic mass measuring 4.5 cm in diameter in the liver, and abdominal CT revealed another liver tumor and an isodensity mass in the spleen. Abdominal MRI and angiography were performed and we presumed the tumors to be two hepatic angiomyolipoma and a splenic hamartoma. As an abdominal CT 21 months later revealed that all tumors were growing, these tomors were surgically resected. The histological diagnoses were hepatic angiomyolipoma and splenic hamartoma.     

Basket pattern blood flow signals discovered in a case of splenic hamartoma by power Doppler ultrasonography

We present the gray-scale ultrasonography (GSUS), power Doppler ultrasonography (PDUS), abdominal computed tomography (CT), and magnetic resonance imaging (MRI) findings for a case of splenic hamartoma in a 27-year-old man, showing a φ 50 mm homogeneous, iso- and hypo-echoic splenic mass with evidence of a small plural cystic lesion. This splenic hamartoma showed increased vascularity on power Doppler sonograms. PDUS showed multiple circular blood flow signals inside the mass (i.e. a basket pattern), which was consistent with the small plural cystic lesion shown by GSUS. Spectral analysis also confirmed arterial and venous flow. CT scans showed that the mass had low-density relative to the normal spleen and MRI showed that the mass was isodense, relative to the normal spleen. Therefore, CT and MRI are not useful for the diagnosis of splenic hamartoma. Ultrasonography can be used to diagnose splenic hamartoma without administration of a contrast material and therefore is an indispensable method for the diagnosis of splenic hamartoma.     

Solitary bile duct hamartoma of the liver

Bile duct hamartomas, also known as von Meyenburg complexes, are benign liver malformations which usually present as multiple small nodules scattered in both lobes of the liver. We report a unique case of bile duct hamartoma. An asymptomatic 30-year-old man who had a solitary cystic lesion underwent partial hepatectomy. Macroscopically, the lesion, measuring 3.6 cm in diameter, was composed of a number of small grayish-white cysts measuring 0.1 to 1.2 cm in diameter. Histologically, the constituent cysts were embedded in a fibrous stroma and were lined by low columnar or cuboidal epithelium. By immunohistochemistry, the MIB-1 index was below 1%, and p53 and carcinoembryonic antigen (CEA) were negative. These findings lead us to conjecture that the lesion was a bile duct hamartoma, although its solitary nature and large size differed from those of typical bile duct hamartoma.     

Solitary bile duct hamartoma of the liver

Bile duct hamartomas, also known as von Meyenburg complexes, are benign liver malformations which usually present as multiple small nodules scattered in both lobes of the liver. We report a unique case of bile duct hamartoma. An asymptomatic 30-year-old man who had a solitary cystic lesion underwent partial hepatectomy. Macroscopically, the lesion, measuring 3.6 cm in diameter, was composed of a number of small grayish-white cysts measuring 0.1 to 1.2 cm in diameter. Histologically, the constituent cysts were embedded in a fibrous stroma and were lined by low columnar or cuboidal epithelium. By immunohistochemistry, the MIB-1 index was below 1%, and p53 and carcinoembryonic antigen (CEA) were negative. These findings lead us to conjecture that the lesion was a bile duct hamartoma, although its solitary nature and large size differed from those of typical bile duct hamartoma.     

Non-random p53 mutations in pediatric undifferentiated (embryonal) sarcoma of the liver.

Undifferentiated (embryonal) sarcoma of the liver (USL) is a rare hepatic tumor in children. Its pathogenesis is largely unknown, but lines of evidence suggest common links to that of mesenchymal hamartoma of the liver (MH). Previously, we found a p53 mutation in a case of pediatric USL. Recently, there was another published report, demonstrating further evidence of p53 alterations in the adult cases. In this study, we analyzed in three cases of pediatric USL and two cases of MH by using PCR-SSCP and direct sequencing technique. The study identified missense mutations in all three cases of USL, but none of MH. The mutations were found specifically in tumor tissue and not detected in the surrounding normal hepatic tissue. Mutation points were localized in exon 7 (Gly245Ser), exon 6 (Arg196Pro), and exon 8 (Arg273Pro), respectively. Immunohistochemical study of p53 protein expression revealed strong immunoreactivity in cases of USL and negative staining in MH. In summary, this study provided a novel data suggesting that mutations of p53 in pediatric USL are not random genetic events and highly possible to be involved in its tumorigenesis.     

Rhabdomyomatous mesenchymal hamartoma: a plaque-type variant in an adult

We present the case of a 40-year-old woman who had a flesh-colored asymptomatic plaque-like lesion above her chin since she was 30 years old. She was generally healthy and physical examination revealed no congenital abnormalities. Histopathology revealed a normal epidermal surface, mature striated muscle fibers arranged randomly within the dermis, and subcutaneous tissue associated with normal-appearing mesenchymal elements such as adipose tissue, collagen, blood vessels, and mature hair follicles. This fits the diagnosis of rhabdomyomatous mesenchymal hamartoma. Our case was different from previously reported cases with regards to the age of onset and clinical presentation. We report this rare adult case and discuss its differential diagnosis.     

Benign liver neoplasms

A variety of benign focal liver lesions are easily characterized with currently available imaging techniques and contrast agents. The most common benign liver lesions, such as hemangioma, bile duct cyst, and FNH, reveal characteristic cross-sectional imaging features that allow an accurate diagnosis. For atypical variants and more uncommon lesions, including HCA, angiomyelioma, infantile hemagioendothelioma, and mesenchymal hamartoma, integration of clinical data can often help in the interpretation of imaging studies. Finally, for the remaining lesions, such as hepatic adenomatosis, the imaging findings may not be specific enough to negate the need for a tissue biopsy.