Giant hepatic mesenchymal hamartoma in a preterm newborn: a case report and literature review

Mesenchymal hamartoma of the liver (MHL) often presents as a painless right upper abdominal mass in young children. However, MHL is rarely reported in the neonatal period. We presented the case of a preterm newborn with a huge MHL. The boy was delivered at 30 weeks weighing 1750 g. Abdominal distention was the initial presentation. Ultrasound and computed tomography showed a highly vascularized mass originating from the left lobe. Liver hemangioma was initially suspected and oral propranolol was administered. However, the tumor was rapidly enlarging, resulting in compromised respiratory status and severe anemia. Surgical resection and neonatal management were successful. The patient required cardiopulmonary resuscitation in the operating room and received packed red blood cells. The histopathological result was mesenchymal hamartoma. The baby recovered well after one-year follow-up. We also reviewed the clinical courses and treatment strategies of preterm MHL cases in published English literature from 1990 to 2021.

Pediatric Mesenchymal Hamartoma of Liver: A Case Report with Histomorphological Differential Diagnosis and Review of Literature

Mesenchymal hamartoma of liver (MHL) is a benign liver tumour that occurs mainly in children, especially those under 2 years old. The pathogenesis of this tumor is still unknown. It is believed that MHL is derived from the Ito cells and either a developmental malformation of primitive hepatic mesenchyme; result of toxic or ischemic insult; or a true neoplasm. It is amenable to treatment and has a good prognosis but presents with varied clinical, imaging and histological findings. However, it can be confused with other hepatic tumors and can mimic malignancy. Therefore, it is important to recognize this rare entity to avoid unnecessary over management. We present a case of MHL in a 3-year-old boy with abdominal distension. Based on the clinical presentation, laboratory and radiological findings a diagnosis of complex cyst of liver was made. A final diagnosis of MHL was given after histopathological examination.

A case of mesenchymal hamartoma of the chest wall of a child

Mesenchymal hamartoma of the chest wall is a rare benign tumor that usually occurs in infants and children. The clinical presentations and imaging features are atypical and difficult to differentiate from malignant tumors. In this article, we present a case with a large mesenchymal hamartoma tumor of the chest wall. A large right-sided chest wall mass was discovered in a 6-month-old boy by his mother. Chest X-ray revealed a thoracic mass with well-defined margins on the right side that expanded into the right ribs. Chest computed tomography showed that the mass originated from the thoracic wall. The patient underwent complete removal of the mass, and histopathology results confirmed a mesenchymal hamartoma.

Liver Tumors in Pediatric Patients

The most recent advance in the care of children diagnosed with hepatoblastoma and hepatocellular carcinoma is the Pediatric Hepatic International Tumor Trial, which opened to international enrollment in 2018. It is being conducted as a collaborative effort by the pediatric multicenter trial groups in North America, Europe, and the Far East. This international effort was catalyzed by a new unified global risk stratification system for hepatoblastoma, an international histopathologic consensus classification for pediatric liver tumors, and a revised 2017 collaborative update of the PRE-Treatment EXTent of disease radiographic based staging system.

[Mesenchymal abdominal tumors in children]

Mesenchymal tumors in childhood comprise benign and malign entities and differ regarding typical sites of manifestation, age peak and clinical symptoms. In some cases biopsy is mandatory. If nephroblastoma is a possible diagnosis, biopsy must be avoided by all means in order to avoid biopsy tract metastasis. Imaging is used to narrow the differential diagnosis, describe the exact extent of the lesion and deliver complete staging. In pediatric patients sonography and MRI are the most important imaging modalities. Low-dose CT of the thorax serves for assessment of possible pulmonary metastases.

Torsion of a mesenchymal hamartoma of the liver in a 1-year-old boy

We report a case of a one-year-old boy who was referred to our clinic suspected of having acute abdomen. On physical examination, the abdomen was soft, diffusely tender with weak peristalsis. Ultrasonography and MRI of the right hemiabdomen demonstrated a well-defined, solid, expansive formation with slightly lobulated contours and an interspersed inhomogeneous structure with overall dimensions of 59 × 45 × 50 mm. After midline laparotomy was performed, a cystic tumor was found, twisted around a pedicle which was arising from the falciform ligament and it measured 5-6 cm in diameter. The tumor appeared to be necrotic. The mass was ligated and extirpated on the pedicle and sent for histopathological analysis. After the surgery, the boy was hemodynamically stable, without respiratory complications and all laboratory findings were within normal limits. Histopathological analysis showed that the tumor was composed of mesenchymal stroma with sparse glimpses of hepatocytes and bile ducts with partly cystic changes lined by orderly epithelium. Given the clinical data, histology and immunohistochemistry analysis (alpha-fetoprotein, CK8/18, hepatocyte, desmin and CD31) a diagnosis of a twisted mesenchymal hamartoma of the liver was made.

Asymptomatic Mesenchymal Hamartoma of the Chest Wall in Child With Fluorodeoxyglucose Uptake on PET/CT-Report of a Case

We had experience with a case of mesenchymal hamartoma of the chest wall (MHCW) with fluorodeoxyglucose (FDG) uptake on positron emission tomography/computed tomography (PET/CT). We reported the first case of asymptomatic MHCW in a child with preoperative PET/CT. Mesenchymal hamartoma of the chest wall is a rare benign tumor that usually presents as a visible chest wall mass or respiratory problems secondary to compression of the lung in early infancy. It is often reported that malignant transformation is extraordinarily rare. Positron emission tomography/CT is useful for diagnosis of malignancy. There is no report of MHCW in a child with preoperative PET/CT before. We examined an asymptomatic 1-year-old girl with an incidental finding on a chest x-ray. Scans of CT and PET/CT were performed before surgical resection. After surgery, the resected tumor was examined histologically. Chest x-ray and CT scan of the chest confirmed a 25- × 20-mm round shaped intrapleural mass containing calcification and destructing the rib, arising from the third rib. Scan of PET/CT demonstrated the mass with light FDG accumulation. Histologically, the mass was homogenous, with thick funicular of hyaline cartilage interdigitating with scattered fiber. There were no malignant cells. No malignant MHCW was demonstrated in the mass, with light FDG accumulation by PET/CT. PET/CT might be a useful tool to distinguish malignant MHCW in children.

Benign liver tumors in children: outcomes after resection

PURPOSE

Benign liver tumors in children are rare and data regarding the surgical outcomes are deficient. We reviewed our experience in the management of these tumors particularly the extent, safety, and effectiveness of surgical resection.

METHODS

Between March 2005 and March 2014, 10/90 liver resections were performed for benign liver tumors. Three other patients received conservative treatment. Demographic characteristics, operative management, morbidity, and mortality were analyzed.

RESULTS

The median age of the patients was 12 months. The distribution of pathology was infantile hepatic hemangioendothelioma/hemangioma (n = 7), mesenchymal hamartoma (n = 4), adenoma (n = 1) and focal nodular hyperplasia (n = 1). Median tumor size was 12.25 cm (range 3.5-21 cm) with a median tumor volume of 576.64 cm(3) (range 13.9-1822.64 cm(3)). Non-anatomic resection was performed in 6/10 patients and the median blood loss was 100 ml (range 10-850 ml). Median length of hospital stay was 7 days (range 5-9 days). There were no mortality, none of the patients had a local recurrence, and all are alive at a median follow-up of 33 months.

CONCLUSIONS

Two-third patients with benign liver tumors were managed with surgical excision, which comprised 11% of our resectional practice. Non-anatomical resection whenever feasible can be performed safely and does not compromise the oncological outcomes.

Liver transplantation for a giant mesenchymal hamartoma of the liver in an adult: Case report and review of the literature

Mesenchymal hamartomas of the liver (MHLs) in adults are rare and potentially premalignant lesions, which present as solid/cystic neoplasms. We report a rare case of orthotopic liver transplantation in a patient with a giant MHL. In 2013, a 34-year-old female sought medical advice after a 2-year history of progressive abdominal distention and respiratory distress. Physical examination revealed an extensive mass in the abdomen. Computed tomography (CT) of her abdomen revealed multiple liver cysts, with the diameter of largest cyst being 16 cm × 14 cm. The liver hilar structures were not clearly displayed. The adjacent organs were compressed and displaced. Initial laboratory tests, including biochemical investigations and coagulation profile, were unremarkable. Tumor markers, including levels of AFP, CEA and CA19-9, were within the normal ranges. The patient underwent orthotopic liver transplantation in November 2013, the liver being procured from a 40-year-old man after cardiac death following traumatic brain injury. Warm ischemic time was 7.5 min and cold ischemic time was 3 h. The recipient underwent classical orthotopic liver transplantation. The recipient operative procedure took 8.5 h, the anhepatic phase lasting for 1 h without the use of venovenous bypass. The immunosuppressive regimen included intraoperative induction with basiliximab and high-dose methylprednisolone, and postoperative maintenance with tacrolimus, mycophenolate mofetil, and prednisone. The recipient’s diseased liver weighed 21 kg (dry weight) and measured 41 cm × 32 cm × 31 cm. Histopathological examination confirmed the diagnosis of an MHL. The patient did not experience any acute rejection episode or other complication. All the laboratory tests returned to normal within one month after surgery. Three months after transplantation, the immunosuppressive therapy was reduced to tacrolimus monotherapy, and the T-tube was removed after cholangiography showed no abnormalities. Twelve months after transplantation, the patient remains well and is fulfilling all normal activities. Adult giant MHL is extremely rare. Symptoms, physical signs, laboratory results, and radiographic imaging are nonspecific and inconclusive. Surgical excision of the lesion is imperative to make a definite diagnosis and as a cure. Liver transplantation should be considered as an option in the treatment of a non-resectable MHL.

Choledochal cyst rupture with an intrahepatic pseudocyst mimicking hepatic mesenchymal hamartoma in an infant

Spontaneous choledochal cyst rupture and consequent biliary peritonitis are rare in children. Here, we report a unique case of intrahepatic bile duct rupture of choledochal cyst type IV that resulted in loculated biliary peritonitis with an intrahepatic pseudocyst mimicking a hepatic mesenchymal hamartoma in a 3-month-old boy. Magnetic resonance cholangiopancreatography can help differentiate these conditions. Regardless of the location, pseudocysts resulting from biliary peritonitis should be considered in cases of choledochal cysts with adjacent fluid collection or cystic lesions.

Differential diagnosis and management of liver tumors in infants

During the first year of life, most of the liver neoplasms are benign in origin, but some of these histologically benign lesions may be challenging in their management. Although most hepatic hemangiomas can be safely observed until involution is documented, some patients will need treatment due to progressive hepatomegaly, hypothyroidism and/or cardiac failure. Large mesenchymal hamartomas may require extensive hepatic resection and an appropriate surgical plan is critical to obtain good results. For malignant neoplasms such as hepatoblastoma, complete surgical resection is the mainstay of curative therapy. The decision about whether to perform an upfront or delayed resection of a primary liver malignant tumor is based on many considerations, including the ease of resection, surgical expertise, tumor histology and stage, and the likely chemosensitivity of the tumor. This article reviews the initial management of the more common hepatic tumors of infancy, focusing on the differential diagnosis and treatment options.

Benign Hepatic Mesenchymal Hamartoma (HMH) - A Case Report

A one-year-old male child presented with progressive enlargement of abdomen and loss of appetite which he had suffered from, since 4 months. Physical examination showed a palpable mass in right hypochondrium. Ultrasonography and MRI showed a solid mass arising from right lobe of liver. The resected mass was well encapsulated, yellowish white in colour and it measured 20 x 18 x 17cm. Cut surface showed a Nutmeg like appearance. Histology showed a well-defined, fibrous capsule with numerous ducts which were lined by flat to low cuboidal epithelium and which were surrounded by concentric layers of fibrous tissue which showed myxoid changes at places. Intervening area showed normal appearing hepatocytes with clear cell changes, dilated congested sinusoids, along with extramedullary haematopoiesis. Based on distinctive morphological features, a histological diagnosis of Benign Hepatic Mesenchymal Hamartoma of liver was made. IHC was not done, as no specific marker has been described for making a differential diagnosis. Benign Hepatic Mesenchymal Hamrtoma (HMH) of liver is an extremely rare tumour of childhood and therefore, the case was considered worth documentation.

Mesenchymal hamartoma mimicking hepatoblastoma

Mesenchymal hamartoma and hepatoblastoma are common causes of hepatic masses in pediatric population; they have similar radiologic and pathologic features. Herein, we present a case of mesenchymal hamartoma that was preoperatively diagnosed as hepatoblastoma. The mass was completely resected instead of being treated with preoperative chemotherapy. Postoperative pathological evaluation revealed mesenchymal hamartoma with free margins; the patient incidentally received the standard treatment. If we would have measured serum AFP in our patient, we could make the correct diagnosis preoperatively, because AFP increases largely in hepatoblastoma. When suspicious exists, serum AFP is a good guide in differentiating hepatoblastoma from mesenchymal hamartoma.

Mesenchymal hamartoma of the liver--a case report and literature review

We report a case of a mesenchymal hamartoma of the liver in a two-year-old boy. He presented to the emergency room with abdominal distention and vomiting. Abdominal ultrasound and computed tomography were performed and revealed a large, intra-peritoneal lesion, with thick wall, multiple cysts of variable size and solid septa. The lesion was surgically resected. Pathological examination revealed a mesenchymal hamartoma of the liver. We are including a short literature review, highlighting the main features of mesenchymal hamartoma of the liver, and discussing its differential diagnosis.

Mesenchymal hamartoma of the liver: a case report

Hepatic mesenchymal hamartoma (HMH) is a hamartomatous growth of the mesenchymal tissue in the liver, which is of an uncertain aetiology. It is a space-occupying lesion that can potentially compress the adjacent organs, resulting in various complications, which include death. Hepatic mesenchymal hamartoma is characterized by the variable proliferation of the myxomatous mesenchyme and the malformed bile ducts. The differential diagnosis includes other paediatric hepatic masses. The diagnosis is typically made during infancy, and a complete resection is invariably curative. Here, we are reporting a case of HMH in a one year old female child who presented with abdominal distension. A clinical diagnosis of malignancy was made, based on the symptoms and imaging studies and a final diagnosis was made only after a histopathological examination. The lesion was potentially benign, with very rare chances of recurrence. This case has been presented due to its rarity.