Cystic hepatic mesenchymal hamartoma: the role of radiology in diagnosis and perioperative management

Abstract

ABSTRACT. A 13-month-old male presented with large hepatic mass that was confirmed diagnostically to be a cystic hepatic mesenchymal hamartoma. The sieve-like appearance of the solid components of the mass, as seen at ultrasonography, and findings of dynamic post-contrast MRI are highlighted here. Beyond diagnostic imaging, we extended our role in patient management through ultrasound-guided intra-operative aspiration of fluid from the cystic components of the tumour to reduce its volume and thereby facilitate surgical resection. Mesenchymal hamartoma (MH) of the liver is a rare, benign developmental malformation composed of a mixture of loose mesenchymal tissue, bile ducts, connective tissue and hepatocytes along with cysts formed either from degenerative areas of mesenchyme or from dilated bile ducts and lymphatics [1,2]. They are predominantly cystic, with the stromal predominant type rarely seen [1]. This pathology was variably labelled as lymphangioma of the liver, bile duct fibroadenoma, cavernous lymphangiomatoid tumour, giant lymphangioma and pseudocystic mesenchymal tumour before being unified under the single term ''mesenchymal hamartoma''. This term conveys that they are not true neoplasms.We present a case that demonstrates an approach from clinical presentation to treatment of MH with an emphasis on dynamic post-contrast MRI and ultrasound appearance. We also highlight the scope for radiologists to expand their role in peri-operative patient management, through the example of the simple but pro-active step of ultrasound-guided intra-operative aspiration of fluid from the massive cystic components of the mass that facilitated surgical excision in this patient. Case reportA 13-month-old male presented with abdominal distension, shortness of breath and loss of appetite for the past 2 months. On examination, non-tender abdominal mass was noted. Besides elevated serum alphafetoprotein (830 IU; normal 0-10) and gamma-glutamyl transpeptidase (127 U l 21 ; normal ,18 U l 21 ), the laboratory reports were unremarkable. There were no signs of sepsis. The patient underwent an ultrasound of the abdomen on the day of admission and an MRI of the abdomen on the following day. A 1-month-old CT scan, performed elsewhere, was reviewed.Ultrasound revealed a well-defined, multicystic mass involving the right lobe of liver. The cysts were anechoic and variable in size (largest 12 cm). Thin (1-2 mm) intervening septae and peripheral solid components were noted. The solid areas were isoechoic to the liver but demonstrated a sieve-like appearance constituted by multiple tiny (1-4 mm) anechoic areas with posterior enhancement and intervening iso-to hyperechoic tissue (Figure 1). Colour Doppler interrogation showed minimal vascularity. The visualised portal and hepatic veins in the vicinity were displaced. There was no biliary dilatation or evidence of portal hypertension. The review of postcontrast CT images showed a circumscribed hypodense mass with minimally enhancing septations and peripheral solid components but no inte...

Differential diagnosis and management of liver tumors in infants

“…On CT-contrast the solid component, septate, and the peripheral rim may enhance. On MRI, MHL has a low signal intensity on T1-weighted magnetic resonance sequences and a variable signal intensity on T2-weighted sequences (Figure 4) [32] . In most patients, the diagnosis of MHL is suggested by imaging and confirmed by histological examination of the resected specimen.…”

Placental Mesenchymal Dysplasia with Hepatic Mesenchymal Hamartoma: A Case Report and Literature Review

“…The best management strategy of PMD with associated HMH is, however, unclear given the poor prognosis. In review of the literature, discussed above, success has been reported with postnatal surgical resection or even minimally invasive methods via percutaneous drainage [8,11]. There has also been success reported with conservative management resulting in complete regression and only intra-hepatic calcifications remaining [12,13].…”

Collision and composite tumors; radiologic and pathologic correlation

“…The alternating solid and cystic components of hamartomas may appear to have a ''swiss cheese'' like pattern. On post-contrast CT, thick solid septa of the hamartoma may demonstrate heterogeneous enhancement [39,[42][43][44] Mesenchymal hamartomas in adults may show a series of histologic modifications: progressive loss of hepatocytes, degeneration of bile duct epithelium, and cystic changes of the mesenchymal component. Mesenchymal hamartomas are benign lesions, which typically have the best prognosis when treated with surgical resection due to potential growth/-mass effect and risk of malignant degeneration [45].…”

“…Mesenchymal hamartomas are benign lesions, which typically have the best prognosis when treated with surgical resection due to potential growth/-mass effect and risk of malignant degeneration [45]. Ultrasound-guided intraoperative aspiration of fluid from cystic components of the hamartomas to reduce its volume may facilitate surgical resection [44]. Other possible differential diagnoses for hepatic lesions including hepatic abscess, hepatic embryonal sarcoma, infantile hemangioendothelioma of liver, simple cysts, hemorrhagic cysts, and hepatoblastoma should be considered and correlated with the patient's clinical presentation and medical history (Fig.…”