A pair of DICER1-positive monozygotic twins: One with pleuropulmonary blastoma, another with acute transient hepatitis

Outcome of two pairs of monozygotic twins with pleuropulmonary blastoma: case report

Background

Pleuropulmonary blastomas (PPB) are rare aggressive paediatric lung malignancies and are among the most common DICER1-related disorders: it is estimated that 75–80% of children with a PPB have the DICER1 mutation. DICER1 mutations are responsible for familial tumour susceptibility syndrome with an increased risk of tumours. In approximately 35% of families with children manifesting PPB, further malignancies may be observed. Symptoms of DICER1 syndrome may vary, even within monozygotic twins. Preventive screening of carriers with DICER1 mutations is important and follow-up is undertaken as recommended by the 2016 International PPB Register.

Case presentation

We present two pairs of monozygotic twins. In one pair of 4-year, 2-month old girls, both with DICER1 mutation, one developed PPB(II) and her identical sibling had acute transient hepatitis. In the other pair of 19-month-old female babies, one had a history of bronchopulmonary hypoplasia and developed PPB(III) without DICER1 mutation, and her identical sibling had allergic asthma. Both patients with PPB were treated with R0 resection and received 12 cycles of postoperative chemotherapy. At the most recent review, the twins had been followed up for six and eight years, respectively, and they all remained healthy. However, the height and weight of the patients with PPB were lower than those of their respective identical sister.

Conclusions

PPB is rare, especially in monozygotic twins. We emphasise the importance of genetic testing and follow-up in monozygotic twins with PPB. During the follow-up, children surviving PPB should be monitored closely for growth and development disorders which caused by chemotherapy.

Clinical analysis of early death in children with pleuropulmonary blastoma in a single center in China

OBJECTIVE

Pleuropulmonary blastoma (PPB) is a rare malignant tumor in childhood that is highly invasive and has poor prognosis. We retrospectively analyzed patients with PPB who died within 30 days in hopes of providing a basis for improving diagnosis and treatment.

METHODS

We retrospectively reviewed six children with PPB who died within 30 days of admission at our hospital from January 2004 to March 2018, including their clinical features, pathological diagnosis, course of treatment, and major causes of death.

RESULTS

Six patients (two female, four male; median age, 38 months) were included. All patients presented with respiratory symptoms. Chest imaging showed that all tumors had diameters greater than 10 cm, with varying degrees of serous effusion. Four patients underwent ultrasound-guided fine-needle aspiration (FNA), one patient underwent exploratory thoracotomy, and one underwent partial tumor resection. Five cases were type III, and another was type II. Four patients developed adverse events while waiting for pathological results after FNA, and four patients were treated with chemotherapy but their tumors failed to decrease in size one to two weeks later. The median hospitalization to death time was 17 days (range, 5-24 days).

CONCLUSIONS

PPB often presents with respiratory symptoms that rapidly develop into respiratory distress. The rapid tumor enlargement contributes to the disease's progression. Chemoreduction in such tumors is not obviously effective, and the mortality rate is high. The main causes of death were respiratory failure and sepsis. Further clinical studies will be required to evaluate the role of initial biopsy compared with upfront total excision.