Giant Mesenchymal Hepatic Hamartomas With Adrenal Involvement Precipitating Respiratory Failure: A Myxomatous Mystery in a Three-Month-Old

The combination of placental mesenchymal dysplasia and hepatic mesenchymal hamartomas is an extremely rare finding. We present the case of a three-month-old female born at 35 weeks gestation with a history of placental mesenchymal dysplasia who presented with non-bilious, non-bloody emesis, and episodes of respiratory distress due to multiple enlarging abdominal cystic lesions. The patient's presentation was unique due to both liver and adrenal solid and cystic lesions. After extensive imaging and multiple biopsies, expert interpretation of biopsy tissue revealed hepatic mesenchymal hamartoma within the liver and the adrenal gland. To our knowledge, this is one of the few documented cases of unresectable hepatic mesenchymal hamartomas with adrenal involvement successfully undergoing a whole liver transplant.

Hepatic mesenchymal hamartoma and undifferentiated embryonal sarcoma of the liver: a pathologic review

This review highlights two rare entities that are predominantly seen in children: hepatic mesenchymal hamartoma (HMH) and undifferentiated embryonal sarcoma of the liver (UESL). HMH is a benign lesion predominantly seen in the first 2 years of life, while UESL is malignant and usually identified in patients between 6 and 10 years of age. UESL may arise in the background of HMH, and the association has been supported by similar chromosomal aberrations (19q13.4). The diagnosis of both lesions is primarily based on histologic evaluation, as the clinical and radiological features are not always typical. The clinicopathologic characteristics, pathogenesis, differential diagnoses and treatment for both lesions are discussed.

Late diagnosis of hepatic mesenchymal hamartoma and placental mesenchymal dysplasia

Placental mesenchymal dysplasia (PMD) is a rare condition characterised by placental enlargement, oedematous villi and multiple anechoic cysts. Hepatic mesenchymal hamartoma (HMH) is a benign proliferation of mesenchymal tissue, commonly seen in infants below the age of 2. We report the case of a 28 years old female who was noted to have a fetus with a well-circumscribed cyst on the liver, suggestive of HMH and a large, thickened placenta, with multiple anechoic cysts, consistent with PMD during the third trimester. There were no other structural abnormalities and at 38 weeks she underwent an induction of labour with normal vaginal delivery of a live female infant. While the aetiology is poorly understood, the increased incidence of HMH with PMD and the morphological similarities of the changes seen in both the placenta and liver, suggests a possible common developmental mechanism. There are only 12 other cases of this concurrent pathology in the literature and only one of these had resulted in a term delivery, and ours is the second one to date.