Pulmonary blastoma with a good prognosis: a case report and review of the literature.

Pulmonary blastoma (PB) is a rare, highly malignant tumor prone to distant metastasis and recurrence, and the prognosis of these patients is often poor. We report a case of metastatic PB with a good prognosis with the aim of providing data to support a clinical diagnosis and treatment. In December 2015, a 43-year-old male patient was admitted to our hospital because of a cough and blood-stained sputum. Positron emission-computed tomography showed massive high-density imaging in the lower lobe of the right lung, with a maximum cross-section of 76 × 58 mm. Thoracoscopic-assisted right lower lobectomy with lymph node dissection was performed. After 1 month, computed tomography showed a high possibility of metastasis. The patient then received docetaxel and cisplatin chemotherapy for a total of six courses. After chemotherapy, enhanced computed tomography showed considerable absorption of pleural effusion, and a left lobe pulmonary nodule was not detected. The postoperative pathological diagnosis was PB, and epithelial and mesenchymal differentiation components were observed. The patient continued to visit the hospital regularly for re-examination and imaging examinations. Currently, no signs of recurrence or distant metastasis have been detected.

Paraplegia after Pneumonectomy - A Rare Complication.

ABSTRACT: Cardiac metastases of lung cancers are common and are associated with serious complications. Locally aggressive lung tumors have the potential to extend into the left atrium via pulmonary veins, which can further complicate by embolizing into the systemic circulation. Pulmonary blastoma (PB) is one of the rare forms of primary lung malignancy and is locally aggressive. We report a rare case of 30 years old male patient who underwent left pneumonectomy for PB. During resection, the tumor was embolized into the descending thoracic aorta, leading to an acute circulatory compromise of both the lower limbs.

Estrogen Receptor Expression in DICER1-related Lesions is Associated With the Presence of Cystic Components.

DICER1 tumor predisposition syndrome results from pathogenic variants in DICER1 and is associated with a variety of benign and malignant lesions, typically involving kidney, lung, and female reproductive system. Over 70% of sarcomas in DICER1 tumor predisposition syndrome occur in females. Notably, pediatric cystic nephroma (pCN), a classic DICER1 tumor predisposition syndrome lesion, shows estrogen receptor (ER) expression in stromal cells. There are also renal, hepatic, and pancreatic lesions unassociated with DICER1 tumor predisposition syndrome that have an adult female predominance and are characterized/defined by ER-positive stromal cells. Except for pCN, the expression of ER in DICER1-associated lesions remains uninvestigated. In the present study, ER expression was assessed by immunohistochemistry in 89 cases of DICER1-related lesions and 44 lesions lacking DICER1 pathogenic variants. Expression was seen in stromal cells in pCN and pleuropulmonary blastoma (PPB) types I and Ir, whereas anaplastic sarcoma of kidney and PPB types II and III were typically negative, as were other solid tumors of non-Müllerian origin. ER expression was unrelated to the sex or age of the patient. Expression of ER showed an inverse relationship to preferentially expressed antigen in melanoma (PRAME) expression; as lesions progressed from cystic to solid (pCN/anaplastic sarcoma of kidney, and PPB types I to III), ER expression was lost and (PRAME) expression increased. Thus, in DICER1 tumor predisposition syndrome, there is no evidence that non-Müllerian tumors are hormonally driven and antiestrogen therapy is not predicted to be beneficial. Lesions not associated with DICER1 pathogenic variants also showed ER-positive stromal cells, including cystic pulmonary airway malformations, cystic renal dysplasia, and simple renal cysts in adult kidneys. ER expression in stromal cells is not a feature of DICER1 perturbation but rather is related to the presence of cystic components.

Adult Pulmonary Blastoma: A Case Report with Spectrum of Rare Manifestations.

Pulmonary blastoma (PB) is an exceedingly rare and aggressive malignant lung neoplasm that has distinct biphasic morphology. In this report, we document rare manifestations and molecular alterations in PB. A 59-year-old non-smoker female, presented with cough and hemoptysis for 4 months. The high-resolution computed tomography chest scan showed a 3.5x2.7 cm mass in the basal segment of the left lung. Positron emission tomography and computed tomography revealed a fluorodeoxyglucose avid lobulated mass in the superior segment of the lower lobe of the left lung. On core biopsy, the diagnosis of pleomorphic carcinoma in a background of adenocarcinoma was made. A definite diagnosis of pulmonary blastoma was established on the left lung lobectomy specimen based on morphological and immunohistochemical findings. Post-surgical biopsy from the scalp swelling showed metastatic deposits. On Next Generation Sequencing (NGS), in addition to conventional CTNNB1 gene mutation, new pathogenic MYCN and ATM gene mutations were detected. Post-chemotherapy, the patient was doing well after 10 months of close follow-up. PB exhibited rare associations in the form of non-smoker status, scalp metastasis, and MYCN and ATM gene mutations on NGS in addition to conventional CTNNB1 gene mutation. Large cohort studies are required to discover the incidence, significance and therapeutic implications of these co-existing pathogenic molecular alterations in PB.

Pulmonary blastoma is successfully treated with immunotherapy and targeted therapy.

Pulmonary blastomas (PB) are an extremely rare type of lung cancer. Currently, no standard treatment exists for PB. Immunotherapy with checkpoint inhibitors and anti-angiogenesis treatments has been an effective method for lung cancer; however, studies on PB treatment are lacking. Herein, we present a case report of successful conversion therapy with immunotherapy and targeted therapy for PB. After receiving treatment with a PD-1 inhibitor (penpulimab) and a multi-target tyrosine kinase inhibitor (anlotinib) treatment, the patient showed an impressive response and underwent a successful operation. We also summarized and reviewed literature reports on PubMed from January 1, 2000, to December 31, 2022, using the keyword "pulmonary blastoma", discussing the efficacy and specifics of chemotherapy and radiotherapy. Immunotherapy, in combination with targeted therapy, should be considered a potential therapeutic strategy for PB.

Fetal Type Morphologies Suggest the Presence of DICER1 Hotspot Mutations in Non-small Cell Lung Cancer.

Germline and somatic pathogenic variants (PVs) in DICER1 , encoding a miRNA biogenesis protein, are associated with a wide variety of highly specific pathologic entities. The lung tumors pleuropulmonary blastoma, pulmonary blastoma (PB), and well-differentiated fetal lung adenocarcinoma (WDFLAC) are all known to harbor DICER1 biallelic variants (loss of function and/or somatic hotspot missense mutations), and all share pathologic features reminiscent of the immature lung. However, the role of DICER1 PVs in non-small cell lung cancer (NSCLC) is relatively unknown. Here, we aimed to establish the spectrum of lung pathologies associated with DICER1 hotspot PVs and to compare the mutational landscape of DICER1 -mutated NSCLC with and without hotspots. We queried DNA sequencing data from 12,146 NSCLCs featuring somatic DICER1 variants. 235 (1.9%) cases harboring ≥ 1 DICER1 PV were found and 9/235 (3.8%) were DICER1 hotspot-positive cases. Histologic review of DICER1 hotspot-positive cases showed that all but one tumor were classified as within the histologic spectrum of PB/WDFLAC, whereas all the DICER1 non-hotspot double variants were classified as lung adenocarcinomas, not otherwise specified. Comparison between the mutational landscape of DICER1 hotspot-positive and hotspot-negative cases revealed a higher frequency of CTNNB1 mutations in the hotspot-positive cases (5/9 vs. 2/225; P <0.00001). We conclude that DICER1 somatic hotspots are not implicated in the most common forms of NSCLC but rather select for morphologic features of lung tumor types such as PB and WDFLAC. As a corollary, cases showing this tumor morphology should undergo testing for DICER1 variants, and if positive, genetic counseling should be considered.

Cytomorphologic and immunocytochemical characterization of pediatric pleuropulmonary blastoma with a comprehensive review of the literature.

INTRODUCTION: Pleuropulmonary blastoma (PPB) is a rare, aggressive, primary intrathoracic malignancy typically seen in infancy and early childhood. Accurate distinction from congenital cystic lung lesions is crucial due to significant prognostic and therapeutic differences. Cytologic features have rarely been described. Establishing a cytodiagnosis is challenging owing to its rarity, lack of awareness, and multiple morphologic mimics. MATERIALS AND METHODS: This was a retrospective study conducted over 8 years. The histopathology and cytopathology databases were searched for all pediatric PPB cases. The corresponding cytologic samples were reviewed to identify characteristic features that can help distinguish PPB from its mimics. RESULTS: There was a total of six cases of pediatric PPB reported during the study period. Of these, four (66.7%) presented as intrathoracic, and two (33.3%) as pleural-based masses. Cytology smears showed discretely scattered and perivascular arrangements of round-oval tumor cells with background eosinophilic stromal material. The tumor cells were mildly pleomorphic (n = 3) with round nuclei, fine chromatin, inconspicuous nucleoli, and scanty cytoplasm; however, three cases showed marked anaplasia, and one each showed necrosis and rhabdoid differentiation. On immunocytochemistry (4/6), these were positive for vimentin and desmin and negative for WT1, chromogranin, SALL4, cytokeratin, CD45, and CD99. FISH (1/6) did not show N-Myc amplification. CONCLUSIONS: Knowledge of the characteristic cytomorphological and immunocytochemical features of PPB is vital to establish a prompt and accurate cytodiagnosis with appropriate clinicoradiologic correlation.

No Pathogenic DICER1 Gene Variants in a Cohort Study of 28 Children With Congenital Pulmonary Airway Malformation.

BACKGROUND: Distinguishing congenital pulmonary airway malformations (CPAMs) from pleuropulmonary blastoma (PPB) can be challenging. Previously diagnosed patients with CPAM may have been misdiagnosed and we may have missed DICER1-associated PPBs, a diagnosis with important clinical implications for patients and their families. To gain insight in potential misdiagnoses, we systematically assessed somatic DICER1 gene mutation status in an unselected, retrospective cohort of patients with a CPAM diagnosis. METHODS: In the Amsterdam University Medical Center (the Netherlands), it has been standard policy to resect CPAM lesions. We included all consecutive cases of children (age 0-18 years) with a diagnosis of CPAM between 2007 and 2017 at this center. Clinical and radiographic features were reviewed, and DICER1 gene sequencing was performed on DNA retrieved from CPAM tissue samples. RESULTS: Twenty-eight patients with a surgically removed CPAM were included. CPAM type 1 and type 2 were the most common subtypes (n = 12 and n = 13). For 21 patients a chest CT scan was available for reassessment by two pediatric radiologists. In 9 patients (9/21, 43%) the CPAM subtype scored by the radiologists did not correspond with the subtype given at pathology assessment. No pathogenic mutations and no copy number variations of the DICER1 gene were found in the DNA extracted from CPAM tissue (0/28). CONCLUSIONS: Our findings suggest that the initial CPAM diagnoses were correct. These findings should be validated through larger studies to draw conclusions regarding whether systematic DICER1 genetic testing is required in children with a pathological confirmed diagnosis of CPAM or not. LEVEL OF EVIDENCE: Level IV.

Intraocular medulloepithelioma: an unusual and challenging entity in paediatric population.

Intraocular medulloepithelioma is a rare, congenital tumour of the non-pigmented ciliary epithelium. It most frequently arises from the ciliary body but can also have its origin from the retina, iris and optic nerve. The age when lesion first appears is typically around 2-10 years. Nearly 50-60% of patients having this lesion may also have secondary features such as cataract and neovascular glaucoma. Those with extrascleral medulloepithelioma are at risk for metastasis. Systemic correlation of the tumour with pleuropulmonary blastoma/DICER1 gene is reported in the literature. Here, we report a case of a 15 years old boy with one year history of right eye proptosis and painful red right eye along with decreased vision for one week. He was assessed and operated for cataract elsewhere three years back. The ophthalmology team managed him for endophthalmitis with intravenous antibiotics, followed by 2 sessions of cryotherapy and finally an enucleation of right eye was performed due to severe pain and no vision in the involved eye. His left eye, general physical examination and systemic evaluation were normal. Histopathology revealed the diagnosis of 'malignant teratoid medulloepithelioma'. Therefore, evaluation of systemic associations for DICER1 gene mutations was performed by the oncology team. For high risk feature of scleral invasion on histopathology, he was treated with chemotherapy. Since the tumour is of rare occurrence; an international expert team with vast research experience in PPB/DICER1 associated tumours was also contacted. He was registered in International PPB/DICER1 registry where a detailed central radiology and pathology review was performed. Genetic counseling and surveillance plan was also suggested by the international registry.

Case 320: Intrathyroidal Thymic Tissue.

HISTORY: A 7-year-old boy with a history of pleuropulmonary blastoma after resection 6 years prior and germline DICER1 mutation was being monitored by physicians at a multidisciplinary genetic predisposition clinic. He demonstrated no evidence of recurrent pleuropulmonary blastoma, and his renal US, chest radiographic, and ocular screening examination results remained normal. Per age-directed screening guidelines, he underwent thyroid US. He had no signs or symptoms of hyper- or hypothyroidism. Physical examination was notable for the absence of thyromegaly or palpable nodule. US at 12-month follow-up showed no change in size or appearance of the left lobe (not shown). However, at this time, the Thyroid Imaging Reporting and Data System (TI-RADS) classification scheme was applied to the stable left lobe finding. The findings were discussed at a multidisciplinary thyroid nodule conference, and the decision was made to bring the patient back for a short-term follow-up for limited unenhanced MRI without sedation. A diagnosis was made based on the follow-up imaging findings.

Classic biphasic pulmonary blastoma: A case report and review of the literature from 2000 to 2022.

Classic biphasic pulmonary blastoma (CBPB), a distinct type of lung cancer, is a dual-phasic tumor characterized by the co-existence of low-grade fetal adenocarcinoma and primitive mesenchymal stroma. Accounting for less than 0.1% of surgically removed lung cancers, CBPB commonly presents in individuals during their fourth to fifth decades of life, with smoking as a significant risk factor. The optimal management strategy entails surgical resection, supplemented by chemotherapy to improve prognosis. The frontline chemotherapeutic agents typically include platinum agents and etoposide, with preoperative neoadjuvant chemotherapy potentially enabling operability for initially inoperable cases. In recent years, targeted therapies, such as antiangiogenic agents, have emerged as promising new treatment strategies for CBPB. For patients exhibiting brain metastases or deemed inoperable, radiation therapy proves to be a crucial therapeutic component. CBPB prognosis is adversely affected by factors such as early metastasis, tumor size exceeding 5 cm, and tumor recurrence. In this regard, serological markers have been identified as valuable prognostic indicators. To exemplify, we recount the case of a 44-year-old female patient with CBPB, wherein serum lactate dehydrogenase levels showed significant diagnostic value. This report further incorporates a comprehensive review of CBPB literature from the past 22 years.

A rare case of Pleuropulmonary blastoma type III with Immunohistochemical Study.

Here we intend to document a rare case of PPB type III in a 2-year male presenting with an extensive tumor occupying the right hemithorax with immunohistochemical (IHC) study. Pleuropulmonary blastoma (PPB) is a rare variably aggressive, dysodontogenetic, childhood primary intrathoracic malignancy which in up to 25% of cases can be extrapulmonary with attachment to the parietal pleura. It is found in pediatric population under 5 years of age. It was initially proposed as a distinct entity by Manivel et al. in 1988. PPB is a proliferation of primitive mesenchymal cells that initially form air-filled cysts lined by benign-appearing epithelium (type I, cystic). Later on, the mesenchymal cells outgrow the cysts with formation of focal solid areas (type II, solid and cystic) and finally, mainly solid mass (type III, solid PPB).

Congenital Pulmonary Airway Malformations With a Reconsideration and Current Perspective on the Stocker Classification.

Congenital cystic pulmonary lesions (CCPLs) are represented by the following entities: congenital pulmonary airway malformation (CPAM), formerly congenital cystic adenomatoid malformation, extra- and intralobar sequestration (EIS), congenital lobar emphysema (overexpansion), and bronchogenic cyst. The developmental model of CPAM histogenesis by Stocker proposed perturbations designated as CPAM type 0 to type 4 without known or specific pathogenetic mechanisms along the airway from the bronchus to the alveolus. This review highlights mutational events either at the somatic level in KRAS (CPAM types 1 and possibly 3) or germline variants in congenital acinar dysplasia, formerly CPAM type 0, and pleuropulmonary blastoma (PPB), type I, formerly CPAM type 4. The potential for overt malignant progression exists in the case of PPB type I and CPAM type 1 in some cases to well-differentiated mucinous adenocarcinoma. On the other hand, CPAM type 2 is an acquired lesion resulting from interruption in lung development secondary to bronchial atresia. The latter is also regarded as the etiology of EIS whose pathologic features are similar, if not identical, to CPAM type 2. These observations have provided important insights into the pathogenetic mechanisms in the development of the CPAMs since the Stocker classification.

Targeting mutant dicer tumorigenesis in pleuropulmonary blastoma via inhibition of RNA polymerase I.

DICER1 mutations predispose to increased risk for various cancers, particularly pleuropulmonary blastoma (PPB), the commonest lung malignancy of childhood. There is a paucity of directly actionable molecular targets as these tumors are driven by loss-of-function mutations of DICER1. Therapeutic development for PPB is further limited by a lack of biologically and physiologically-representative disease models. Given recent evidence of Dicer's role as a haploinsufficient tumor suppressor regulating RNA polymerase I (Pol I), Pol I inhibition could abrogate mutant Dicer-mediated accumulation of stalled polymerases to trigger apoptosis. Hence, we developed a novel subpleural orthotopic PPB patient-derived xenograft (PDX) model that retained both RNase IIIa and IIIb hotspot mutations and recapitulated the cardiorespiratory physiology of intra-thoracic disease, and with it evaluated the tolerability and efficacy of first-in-class Pol I inhibitor CX-5461. In PDX tumors, CX-5461 significantly reduced H3K9 di-methylation and increased nuclear p53 expression, within 24 hours' exposure. Following treatment at the maximum tolerated dosing regimen (12 doses, 30 mg/kg), tumors were smaller and less hemorrhagic than controls, with significantly decreased cellular proliferation, and increased apoptosis. As demonstrated in a novel intrathoracic tumor model of PPB, Pol I inhibition with CX-5461 could be a tolerable and clinically-feasible therapeutic strategy for mutant Dicer tumors, inducing antitumor effects by decreasing H3K9 methylation and enhancing p53-mediated apoptosis.

Cervical Pleuropulmonary Blastoma-like Tumor Associated With DICER1 and TP53 Mutations.

We describe a very unusual cervical tumor in a 12-yr-old patient with a clinical history indicative of DICER1 syndrome. Morphologic, immunohistochemical, and molecular genetic analysis together helped to diagnose this lesion as a cervical pleuropulmonary blastoma-like tumor, associated with TP53 and DICER1 mutations. The tumor displayed usual histologic features including mixtures of embryonal rhabdomyosarcoma, sarcomatous cartilage, compact blastema, primitive spindle cells and anaplasia, akin to type III pleuropulmonary blastoma, and trabecular and retiform patterns. In addition to expanding the phenotypic spectrum of DICER1 -associated conditions, we draw attention to genotype-phenotype correlations in DICER1 -associated tumors, particularly as they relate to the discovery of a heritable tumor predisposition syndrome.

Health-related quality of life in children and adolescents with pleuropulmonary blastoma: A report from the International PPB/DICER1 Registry.

PURPOSE: Pleuropulmonary blastoma (PPB) is the most common lung cancer of infancy and early childhood and is associated with germline DICER1 variants. Type I and Ir PPB are cystic lesions treated surgically, with a subset of children with type I receiving chemotherapy. Type II and III are more aggressive lesions, treated with surgery, intensive chemotherapy and potentially radiation. We sought to assess health-related quality of life (HRQoL) in children with PPB and known germline DICER1 variants. METHODS: Children with a diagnosis of PPB or germline DICER1 pathogenic variant without history of PPB or other DICER1-related neoplasm (DICER1+ only) were enrolled in the International PPB/DICER1 Registry. Parent reports for participants aged 2-17 years for the PedsQL v.4 and PedsQL Multidimensional Fatigue Scale v.3 were collected. Fatigue, physical, and psychosocial function scores were compared. RESULTS: Analysis included 84 participants (PPB type Ir = 20, type I = 15, type II/III = 27, DICER1+ only = 22). Total fatigue scores of participants with type I and II/III PPB were lower compared to DICER1+ only, with effect size larger in type II/III (-0.82 vs. -0.40). Total psychosocial and physical functioning scores were lower in participants with type I and type II/III PPB compared to DICER1+ only, with larger effects noted in type II/III. Female sex was suggestive of worse HRQoL for both type I/Ir and type II/III cohorts. CONCLUSIONS: These data demonstrate the importance of regular HRQoL assessment in patients with a history of PPB as well as the importance and feasibility of studying HRQoL in children with rare tumors.