Congenital pulmonary myofibroblastic tumor: a case report with cytogenetic analysis and review of the literature

Congenital peribronchial myofibroblastic tumor (CPMT): a case report with long term follow-up and next-generation sequencing (NGS)

BACKGROUND

Congenital peribronchial myofibroblastic tumor (CPMT) is an extremely rare lung disease in infants. It shows benign behavior and has a favorable survival after surgical treatment. CPMT was reported only in cases. Here, we report the longest follow-up known case of CPMT and review the clinical, radiographic and histopathological features of the published literature.

CASE PRESENTATION

Ultrasound examination at 30 weeks of gestational age of a healthy 29-year-old female revealed a solid mass in the left lung. Computed tomography (CT) revealed a mass in the left lower lobe. The tumor was removed by lobectomy and pathologically diagnosed with CPMT. The tumor was composed of cartilage, spindle cells and oval cells. Vimentin was strongly positive. Smooth muscle actin (SMA) was positive in the spindle cells. The histopathologic and immunohistochemical features were similar to those in the literature. No ETV6-NTRK3 fusion or ALK rearrangement was detected. Gene mutations in JAK2 and SMO were detected by NGS. She is currently alive for 8 years with no evidence of disease recurrence.

CONCLUSIONS

CPMT is a rare lung tumor in infants. Surgical treatment is recommended for CPMT. The prognosis after successful surgery is favorable. The final diagnosis was histopathologic findings. Due to its cellularity, mitotic activity and rapid growth, long-term follow-up should be strengthened. The present patient is alive and well for 8 years after the surgery without recurrence. Gene mutations in JAK2 and SMO were detected, which may be associated with the formation of CPMT.

Infantile inflammatory myofibroblastic tumors: clinicopathological and molecular characterization of 12 cases

Inflammatory myofibroblastic tumors arising in infants are rare, poorly investigated and mostly reported as isolated cases or as a part of larger series thus, their clinicopathological and molecular features are essentially unknown. Archival files from two large pediatric institutions and a tumor registry were queried for pediatric inflammatory myofibroblastic tumors. Available material from patients ≤12 months of age was reviewed. Additional immunostains (ALK-1, D240, WT1) and ALK-FISH studies were performed as needed. Targeted anchored multiplex PCR with next-generation sequencing was done in all cases. A total of 12 of 131 infantile cases (mean 5.5 months) were identified (M:F of 2:1). Anatomic locations included intestinal/mesenteric (n = 6), head/neck (n = 3), and viscera (n = 3). Half of tumors showed a hypocellular myxoid pattern, perivascular condensation, and prominent vasculature with vague glomeruloid structures present in four of them. The remaining cases exhibited a more cellular pattern with minimal myxoid component. ALK-1 immunohistochemistry was positive in most cases (11/12) with cytoplasmic-diffuse (n = 6), cytoplasmic-granular (n = 2), and dot-like (n = 3) staining patterns. ALK fusion partners identified in five cases included EML4, TPM4, RANBP2, and a novel KLC1. Three inflammatory myofibroblastic tumors showed fusions with other kinases including TFG-ROS1 and novel FN1-ROS1 and RBPMS-NTRK3 rearrangements. Favorable outcome was documented in most cases (10/11) with available follow-up (median 17 months) while three patients were successfully treated with crizotinib. In summary, infantile inflammatory myofibroblastic tumors are rare and can exhibit paucicellular, extensively myxoid/vascular morphology with peculiar immunophenotype mimicking other mesenchymal or vascular lesions. All tumors harbored kinase fusions involving ALK, ROS1, and NTRK3 including three novel fusion partners (KLC1, FN1, and RBPMS, respectively). A favorable response to crizotinib seen in three cases supports its potential use in infants as seen in older patients. Awareness of these unusual morphologic, immunophenotypic, and molecular features is critical for appropriate diagnosis and optimized targeted therapy.

Congenital peribronchial myofibroblastic tumor: a case report and review of the literature

BACKGROUND

Congenital peribronchial myofibroblastic tumor is a rare, solid mesenchymal tumor of the neonate, usually associated with non-immune hydrops fetalis.

CASE REPORT

We present a case of congenital peribronchial myofibroblastic tumor, in whom a right lung mass was detected in intrauterine life. 12 days after delivery by caesarean section, right lobectomy was performed. The tumor was limited to the lung, and was composed of spindle cells, proliferating around a bronchial unit. Central necrosis and 4-5 mitoses per 10 high power fields were present. The patient is well 26 months after surgery.

CONCLUSION

We report this rare tumor with clinical, radiological and pathologic findings and a review of the literature.

Identification of novel ALK rearrangement A2M-ALK in a neonate with fetal lung interstitial tumor

Fetal lung interstitial tumor (FLIT) is a recently reported type of congenital lung lesion comprising solid and cystic components. The pathological features include unique interstitial mesenchyme-based cell proliferation, and differ from other neoplasms represented by pleuropulmonary blastoma or congenital peribronchial myofibroblastic tumor. FLIT is extremely rare and its gene expression profile has not yet been reported. We provide the first report of a novel chromosomal rearrangement resulting in α-2-macroglobulin (A2M) and anaplastic lymphoma kinase (ALK) gene fusion in a patient with FLIT. The tumor cells contained a t(2;12)(p23;p13) and were mesenchymal in origin (e.g., inflammatory myofibroblastic tumors), suggesting the involvement of ALK in this case of FLIT. Break apart fluorescence in situ hybridization demonstrated chromosomal rearrangement at ALK 2p23. Using 5'-rapid amplification of cDNA ends, we further identified a novel transcript fusing exon 22 of A2M to exon 19 of ALK, which was confirmed by reverse-transcription polymerase chain reaction. The corresponding chimeric gene was subsequently confirmed by sequencing, including the genomic break point between intron 22 and 18 of A2M and ALK, respectively. Discovery of A2M as a novel ALK fusion partner, together with the involvement of ALK, provides new insights into the pathogenesis of FLIT, and suggests the potential for new therapeutic strategies based on ALK inhibitors.

Congenital peribronchial myofibroblastic tumor: a case study and literature review

Congenital peribronchial myofibroblastic tumor (CPMT) is a benign pulmonary spindle cell neoplasm of intrauterine and perinatal period, which is thought to arise from primitive peribronchial mesenchyme. We present a case detected incidentally in a one-month-old infant. The solid and partially necrotic tumor involved the right middle and lower lobes of the lung with extension to the diaphragm. Histologically, the tumor was composed of fasciculated monotonous spindle cells, proliferating peribronchiolar cartilage and round cells with rich vasculature, and high mitotic activity was identified in the round cell area. Immunohistochemical and electron microscopic studies showed that the spindle cells were myofibroblastic in phenotype. Although the tumor showed several malignant pathological features, recurrence was not observed in the two-year follow-up period, consistent with the benign clinical behavior of CPMT.

Congenital peribronchial myofibroblastic tumor: comparison of fetal and postnatal morphology

Congenital peribronchial myofibroblastic tumor (CPMT) is a solid pulmonary tumor found in fetuses and neonates with pathology characterized by a proliferation of bland spindled cells with or without irregular cartilaginous islands. It has previously been reported in the literature as a fibrosarcoma, leiomyosarcoma, and hamartoma, among other names. Although complications such as fetal hydrops can occur, the prognosis is generally good if the infant can survive long enough for mass resection. We present a case of a CPMT resected by antenatal fetal surgery at 23 weeks in gestation, with additional tumor resected following birth when the infant was 6 weeks of age. The pathology of this lesion showed a marked increase in the cartilaginous component after birth as well as a decrease in cellularity and mitotic activity. This case presents a unique opportunity to examine the progression of a congenital tumor excised by prenatal and postnatal resections.

Congenital peribronchial myofibroblastic tumor: a case report

We describe a rare occurrence of congenital peribronchial myofibroblastic tumor of the lung presenting in early fetal life. A female patient in the 24th week of gestation who presented with polyhydramnios was admitted for examination. Ultrasound examination revealed a mass compromising the lungs. Because the intrauterine fetal death was revealed by the ultrasound, delivery was induced. Necropsy revealed a pulmonary lesion compromising the left lower pulmonary lobe together with hepatomegaly. Microscopic analysis of the lung showed a lesion with a storiform arrangement of spindle cells with focal peribronchial distribution. Hepatic architecture was diffusely altered by fibrotic tissue. Immunohistochemical analysis on the pulmonary lesion showed high vimentin positivity in the fusocellular components, pointing to the mesenchymal nature of the lesion. Significant differentiation of smooth muscle tissue, as indicated by high HHF35 positivity, was also observed. Electron microscopy on the pulmonary lesion revealed elongated cells with some cytoplasmatic processes, a finding that is also compatible with mesenchymal differentiation.

Primary and metastatic lung tumors in the pediatric population: a review and 25-year experience at a large children's hospital

CONTEXT

Primary lung neoplasms are rare in children, but they comprise a broad and interesting spectrum of lesions, some of which are familiar from other tissue sites, and some of which are unique to the pediatric lung.

OBJECTIVE

To determine the relative incidence of primary and metastatic lung tumors in children and adolescents through a single-institution case series, to compare these data to reports in the medical literature, to discuss the clinical and pathologic features of primary tumors of the tracheobronchial tree and lung parenchyma in children, and to provide recommendations for handling pediatric lung cysts and tumors.

DATA SOURCES

A 25-year single institutional experience with pediatric lung tumors, based on surgical biopsies and resections at Texas Children's Hospital from June 1982 to May 2007, an additional 40 lung tumors referred in consultation, and a review of the medical literature.

CONCLUSIONS

A total of 204 pediatric lung tumors were diagnosed at our institution, including 20 primary benign lesions (9.8%), 14 primary malignant lesions (6.9%), and 170 secondary lung lesions (83.3%). The ratio of primary benign to primary malignant to secondary malignant neoplasms is 1.4:1:11.6. The common types of lung cancer in adults are exceptional occurrences in the pediatric population. The most common primary lung malignancies in children are pleuropulmonary blastoma and carcinoid tumor. Other primary pediatric lung tumors include congenital peribronchial myofibroblastic tumor and other myofibroblastic lesions, sarcomas, carcinoma, and mesothelioma. Children with primary or acquired immunodeficiency are at risk for Epstein-Barr virus-related smooth muscle tumors, lymphoma, and lymphoproliferative disorders. Metastatic lung tumors are relatively common in children and also comprise a spectrum of neoplasia distinct from the adult population.

Fetal hydrops associated with congenital pulmonary myofibroblastic tumor

Abstract We report on a fetus with a congenital pulmonary myofibroblastic tumor, the prenatal detection of which with imaging modalities has not been reported up until now. A 32-year-old woman was referred to our hospital at 29 weeks' gestation because of severe fetal hydrops. Sonograms and magnetic resonance imaging showed a large solid tumor in the left thorax. The fetus died in utero the next day. Autopsy confirmed that the tumor was confined to the lower lobe of the left lung, and circulatory insufficiency from compression by the tumor was considered to be the cause of fetal hydrops and demise. Histologic examination revealed that the tumor was composed of uniform short spindle cells with no atypia and a large number of vessels. In addition, with immunohistochemical studies, the tumor cells were stained for calponin but not for cluster differentiation (CD)-31, CD-34, alpha-smooth muscle actin or S-100.

Myofibroblastic tumor causing severe neonatal distress. Successful surgical resection after embolization

This report describes a case of a term male 3.1 kg, normal delivery, 38 weeks of gestation with a record of hydramnios by prenatal sonography. He had fetal acute suffering and respiratory distress. The first radiographic study showed a mass filling the whole left thorax cage causing erosion of the inferior edge of the third rib. The mediastinum was displaced to the right. Computed tomography scan confirmed a homogeneous tumor that filled the left thorax and displaced the mediastinum to the right without invasion. Surgical biopsy informed of a highly vascularized mesenchymal tumor. The tumor was embolized with Ivalon microparticles obtaining a nearly avascular mass. Complete surgical excision was made, including the whole mass and costal segments. Microscopically, it was an inflammatory myofibroblastic tumor. It was composed mainly of spindle-shaped cells without malignant features. On immunohistochemistry, the tumor showed positive staining for vimentin, whereas antidesmin antibodies and S-100 protein were negative. The aim of this article is to present an extremely uncommon case of neonatal distress caused by an intrathoracic, extrapulmonary myofibroblastic tumor. Complete surgical resection was possible after embolization.

Congenital multifocal inflammatory pseudotumor: a case report

Inflammatory pseudotumor is an uncommon benign tumor found in various sites throughout the body. The etiology is unclear with evidence to support both neoplastic and infective processes. The authors present a case with several unique features. It represents the first reported case detected antenatally. The tumor was found separately within the abdomen and thorax. The thoracic component of the tumor was managed without resection or ablative treatment but showed spontaneous regression.