Pediatric primary lung adenocarcinoma in the absence of congenital pulmonary airway malformation

Primary lung adenocarcinoma in three adolescent patients affected by bone sarcomas

Pediatric primary lung carcinomas are extremely rare. Apart from known associations with congenital adenomatoid malformations, cases of primary lung adenocarcinomas after prolonged treatments of pediatric malignancy have been reported. We describe the morphological and molecular features of three cases of lung adenocarcinoma developed in adolescents aged 8 to 17 years during progression of their bone osteosarcoma or Ewing sarcomas. The morphological features overlapped those of adult lung adenocarcinoma including in situ, minimally invasive, and invasive forms. EGFR gene mutations were found in all three cases by targeted next-generation sequencing. The two patients with Ewing sarcoma had no progression of their lung cancer and no further progression of the metastatic bone tumor after additional chemo- and radio-therapy. Conversely, the osteosarcoma patient refused further treatments after thoracic surgery for metastatic osteosarcoma and locally advanced adenocarcinoma and died 2 years later of widespread distant metastases. Our results indicate that primary lung cancer might originate in pediatric patients during prolonged adjuvant therapies for primary bone neoplasm, and this possibility should be considered in the presence of suspected lung disease progression to correctly monitor the primary tumor evolution and define the appropriate therapeutic strategy at each time point. If appropriately treated, second primary lung cancer may not affect the patients' prognosis. The pathogenetic mechanisms of these rare lung adenocarcinomas are not clear, but the presence of EGFR mutations in all three cases indicates an oncogene addiction of the lung tumor, rather than a direct cancerogenic effect of the sarcoma-related treatment.

Pediatric lung adenocarcinoma presenting with brain metastasis: a case report

BACKGROUND

Diagnosis and treatment of primary lung adenocarcinoma in children remains challenging given its rarity. Here we highlight the clinical history, pathological evaluation, genomic findings, and management of a very young patient with metastatic lung adenocarcinoma.

CASE PRESENTATION

A 10-year-old white girl presented with brain metastases due to primary pulmonary adenocarcinoma. Next generation sequencing analysis with "Comprehensive Cancer Panel" highlighted the presence of multiple non-targetable mutations in the FLT4, UBR5, ATM, TAF1, and GUCY1A2 genes. She was treated aggressively with chemotherapy, surgery, and radiation therapy for local and distant recurrence. Eventually, therapy with nivolumab was started compassionately, and she died 23 months after diagnosis.

CONCLUSIONS

Extremely rare cancers in children such as lung adenocarcinoma need accurate and specific diagnosis in order to develop an optimal plan of treatment. It is also necessary to underline that "children are not little adults," thus implying that an adult-type cancer in the pediatric population might have a different etiopathogenesis. Diagnostic confirmation and primary treatment of such rare conditions should be centralized in reference centers, collaborative networks, or both, with multidisciplinary approaches and very specific expertise.

Minimally Invasive Adenocarcinoma of the Lung as Second Malignant Neoplasm Following Pediatric Rhabdomyosarcoma

Primary pulmonary tumors are extremely rare in the pediatric population; however, sporadic cases of invasive pulmonary adenocarcinoma as a second malignant neoplasm (SMN) have been described in survivors of pediatric cancers. Pediatric patients with rhabdomyosarcoma (RMS) have a particularly increased risk of developing a SMN when compared to the general population, though pulmonary adenocarcinoma has not been previously described in a RMS patient. A 12-year-old female previously treated for stage IV pelvic RMS was found to have a left pulmonary nodule on surveillance computed tomography. The nodule was detected 4.25 years after the completion of treatment, which included resection, chemotherapy, and radiation to the abdomen and pelvis. Wedge resection of the pulmonary lesion was performed with negative margins. Histopathological examination revealed minimally invasive adenocarcinoma. Pulmonary adenocarcinoma may rarely present as a SMN in pediatric cancer survivors. The pathogenesis of this association is not yet entirely clear, but may include chemotherapy-induced mutagenesis and/or genetic predisposition. As pulmonary adenocarcinoma may present as a lung lesion radiographically indistinguishable from metastatic RMS, it should be considered in the differential diagnosis of any pediatric RMS survivor presenting with a new pulmonary nodule, especially in cases with late recurrence.

Primary lung and large airway neoplasms in children: current imaging evaluation with multidetector computed tomography

Multidetector computed tomography (MDCT) offers an important noninvasive imaging modality for confirmation and further characterization of primary lung and large airway neoplasms encountered in pediatric patients. Children represent a unique challenge in imaging, not only because of unique patient factors (eg, inability to follow instructions, motion, need for sedation) but because of the technical factors that must be optimized to reduce radiation dose. This article reviews an MDCT imaging algorithm, up-to-date imaging techniques, and clinical applications of MDCT for evaluating benign and malignant primary neoplasms of lung and large airway in infants and children.