Translocation t(12;17)(q24.1;q21) as the sole anomaly in a nasal chondromesenchymal hamartoma arising in a patient with pleuropulmonary blastoma

Angiomyolipomatous Lesions of the Nasal Cavity (Sinonasal Angioleiomyoma with Adipocytic Differentiation): A Multi-Institutional Immunohistochemical and Molecular Study

PURPOSE

Mesenchymal neoplasms composed of vascular, smooth muscle, and adipocytic components are uncommon in the nasal cavity. While angioleiomyoma (AL) is a smooth muscle tumor in the Head & Neck WHO classification, it is considered of pericytic origin in the Skin as well as Soft Tissue and Bone classifications. For nasal AL with an adipocytic component, the terms AL with adipocytic differentiation and angiomyolipoma (AML) have been applied, among others. AML is a type of perivascular epithelioid cell tumor (PEComa), most often arising in the kidney, sometimes associated with the tuberous sclerosis complex (TSC). It is uncertain whether nasal cavity AML and AL are best considered hamartomas or neoplasms, as their genetics are largely unexplored.

METHODS

We performed a multi-institutional retrospective study of nasal cavity mesenchymal lesions. Patient demographics, clinical histories, and histologic and immunohistochemical findings were collected. DNA and RNA were extracted from formalin-fixed, paraffin-embedded tissue and analyzed by SNP-based chromosomal microarray, targeted RNA fusion sequencing, and whole-exome sequencing.

RESULTS

Fifteen lesions (3-42 mm) were identified, predominantly in male (87%) patients with a median age of 60. Patients typically presented with obstructive symptoms, and none had a history of TSC. One AL was a recurrence from six years prior; 11 cases showed no recurrence (median 4.7 years, range: 0.88-12.4). Morphologically, 11 AML contained 30-80% smooth muscle, 10-25% vasculature, and 2-60% adipose tissue, while four AL contained 70-80% smooth muscle and 20-30% vasculature. Other histologic observations included ulceration, thrombosis, inflammation, myxoid change, senescent nuclei, and extramedullary hematopoiesis; no well-developed epithelioid cell morphology was identified. Immunohistochemically, all cases were positive for smooth muscle markers (actin, desmin, and/or caldesmon) and negative for melanocytic markers. Molecular analysis revealed loss of 3p and 11q in a single AML. No other known pathogenic copy number or molecular alterations were seen, including in TSC1/2, TFE3, or NOTCH2.

CONCLUSION

Nasal cavity AML lacks morphologic, immunophenotypic, and genetic features of PEComa family AML. The significant histologic overlap between nasal AML and AL without distinguishing molecular features in either entity suggests "sinonasal angioleiomyoma with adipocytic differentiation" may be the most appropriate terminology for hybrid vascular and smooth muscle lesions containing adipocytic components.

Angiomyolipomatous Lesions of the Nasal Cavity (Sinonasal Angioleiomyoma with Adipocytic Differentiation): A Multi-Institutional Immunohistochemical and Molecular Study

Purpose

Mesenchymal neoplasms composed of vascular, smooth muscle, and adipocytic components are uncommon in the nasal cavity. While angioleiomyoma (AL) is a smooth muscle tumor in the Head & Neck WHO classification, it is considered of pericytic origin in the Skin as well as Soft Tissue and Bone classifications. For nasal AL with an adipocytic component, the terms AL with adipocytic differentiation and angiomyolipoma (AML) have been applied, among others. AML is a type of perivascular epithelioid cell tumor (PEComa), most often arising in the kidney, sometimes associated with the tuberous sclerosis complex (TSC). It is uncertain whether nasal cavity AML and AL are best considered hamartomas or neoplasms, as their genetics are largely unexplored.

Methods

We performed a multi-institutional retrospective study of nasal cavity mesenchymal lesions. Patient demographics, clinical histories, and histologic and immunohistochemical findings were collected. DNA and RNA were extracted from formalin-fixed, paraffin-embedded tissue and analyzed by SNP-based chromosomal microarray, targeted RNA fusion sequencing, and whole-exome sequencing.

Results

Fifteen lesions (3 to 42 mm) were identified predominantly in male (87%) patients with a median age of 60. Patients typically presented with obstructive symptoms, and none had a history of TSC. One AL was a recurrence from six years prior; 11 cases showed no recurrence (median 4.7 years, range: 0.88-12.4). Morphologically, 11 AMLs contained 30-80% smooth muscle, 10-25% vasculature, and 2-60% adipose tissue, while four ALs contained 70-80% smooth muscle and 20-30% vasculature. Other histologic observations included surface ulceration, vascular thrombosis, chronic inflammation, and myxoid change; no well-developed epithelioid cell morphology was identified. Immunohistochemically, all cases were positive for smooth muscle markers (actin and/or desmin) and negative for melanocytic markers. Molecular analysis revealed loss of 3p and 11q in a single AML. No other known pathogenic copy number or molecular alterations were seen, including in TSC1/2, TFE3, or NOTCH2.

Conclusion

Nasal cavity AML lacks morphologic, immunophenotypic, and genetic features of PEComa family AMLs. The significant histologic overlap between nasal AML and AL without distinguishing molecular features in either entity suggests "sinonasal angioleiomyoma with adipocytic differentiation" may be the most appropriate terminology for hybrid vascular and smooth muscle lesions containing adipocytic components.

Pediatric nasal chondromesenchymal hamartomas: a case series

PURPOSE

Nasal chondromesenchymal hamartomas (NCMH) are rare, predominantly benign tumors of the sinonasal tract. The distinction from higher grade malignancy may be challenging based on imaging features alone. To increase the awareness of this entity among radiologists, we present a multi-institutional case series of pediatric NCMH patients showing the varied imaging presentation.

METHODS

Descriptive assessment of imaging appearances of the lesions on computed tomography (CT) and magnetic resonance imaging (MRI) was performed. In addition, we reviewed demographic information, clinical data, results of genetic testing, management, and follow-up data.

RESULTS

Our case series consisted of 10 patients, with a median age of 0.5 months. Intraorbital and intracranial extensions were both observed in two cases. Common CT findings included bony remodeling, calcifications, and bony erosions. MRI showed heterogeneous expansile lesion with predominantly hyperintense T2 signal and heterogenous post-contrast enhancement in the majority of cases. Most lesions exhibited increased diffusivity on diffusion weighted imaging and showed signal drop-out on susceptibility weighted images in the areas of calcifications. Genetic testing was conducted in 4 patients, revealing the presence of DICER1 pathogenic variant in three cases. Surgery was performed in all cases, with one recurrence in two cases and two recurrences in one case on follow-up.

CONCLUSION

NCMHs are predominantly benign tumors of the sinonasal tract, typically associated with DICER1 pathogenic variants and most commonly affecting pediatric population. They may mimic aggressive behavior on imaging; therefore, awareness of this pathology is important. MRI and CT have complementary roles in the diagnosis of this entity.

Treatment and prognosis of pleuropulmonary blastoma: A single-center report of 31 cases

OBJECTIVES

Pleuropulmonary blastoma (PPB) is a very rare and highly aggressive neoplasm occurring in children, mostly under 6 years of age. We assessed the clinical characteristics, treatment modalities, treatment outcomes, and prognostic factors affecting survival in patients with PPB treated at our institution over a 10-year period to improve the prognosis.

METHODS

From November 2008 to November 2019, 31 children (21 boys and 10 girls) with a median age of 30 months (ranging, 22 days to 54 months) were treated at our institution. Here we describe the patient characteristics, treatment modalities, and treatment outcomes. The Kaplan-Meier method was used to estimate the progression-free survival (PFS) and overall survival (OS). Log-rank test was performed for comparison between groups.

RESULTS

Three children were lost to follow-up and two were dead due to postoperative complications. Of the 26 patients included in the follow-up, 16 PPB patients displayed tumor-free survival. The 5-year PFS and OS were 60.4% and 60.1% respectively. By stratified statistical analysis, the 5-year PFS and OS of type I PPB were 100%, while those of type III PPB were 43.7% and 43%, respectively. The 5-year PFS and OS of complete tumor resection were 76.5% and 75.6%, respectively, while those with tumor residue were 31.3%. The 5-year PFS and OS combined with chemotherapy were 62.2% and 61.6%, respectively, while those without chemotherapy were 0%.

CONCLUSIONS

PPB is an aggressive neoplasm. The main factors related to the prognosis of PPB are pathological type, tumor resection degree, and postoperative adjuvant therapy.

A Systematic Review of Nasal Chondromesenchymal Hamartoma (NCMH) with a New Case Report

Nasal chondromesenchymal hamartoma (NCMH) is a very rare, benign sinonasal tract tumor commonly affecting infants. In this paper, in addition to presenting a systematic review of the literature on NCMH, we also report an unusual case of NCMH in an adolescent patient. A systematic review conducted following the PRISMA guidelines. PubMed, EMBASE and manual search through references of relevant publication were utilised to gather all published case-reports of NCMH. Data collected from each case-report for patient demographics, site and size of NCMH, clinical presentation, co-morbidities, diagnostic methods, treatment options and follow-up methods. The systemic review collected sixty-two case-reports of NCMH (including our case) affecting 42 men and 21 women (2:1 male to female ratio). Mean average age was 5.1 years (age range: 1 day to 70 years). The anatomical sites of the tumor were: nasal cavity (n = 17), paranasal sinuses (n = 30), orbital region (n = 17), and the base of the skull (n = 16). The reported clinical manifestations were nasal obstruction or congestion (n = 29), nasal mass (n = 27), epistaxis (n = 6), orbital symptoms (n = 14). NCMH is a very rare cause of nasal masses in infants and toddlers. Our case and previous case reports confirm that NCMH can mimic other benign and malignant tumors, therefore we should be vigilant for rare pathologies that lead to nasal masses. Recently the link between DIECR1 mutation with NCMH has been established, so NCMH should be considered in any patient with nasal or orbital symptoms with a history of DICER1-related tumor spectrum.

THE "-OMAS" and "-OPIAS": Targeted and Philosophical Considerations Regarding Hamartomas, Choristomas, Teratomas, Ectopias, and Heterotopias in Pediatric Otorhinolaryngologic Pathology

The spectrum of "developmental" lesions that occur in the head and neck predominantly congenital in origin and arising at birth and/or discovered in childhood is broad and fascinating. These have been grouped into categories such as "ectopias", "heterotopias", "hamartomas", and "choristomas". On a philosophical and consequently systematic level, these lesions, mostly benign tumors seem to lack a true understanding of the pathogenetic foundation on which to base a more unified taxonomic designation. In this review, we will consider some of these select tumors as they represent syndromic associations (nasal chondromesenchymal hamartoma and DICER1 syndrome), the lingual choristoma from the perspective of its nomenclature and classification, lesions with ectopic meningothelial elements, and teratomas and the enigmatic "hairy polyp" in reference to a broader discussion of pathogenesis and pluripotent cells in the head and neck. A consistent thread will be how these lesions are designated with some final thoughts on future directions regarding the investigation of their pathogenesis and taxonomic nomenclature.

Nasal Chondromesenchymal Hamartoma: Rare Case Report in an Elderly Patient and Brief Review of Literature

Hamartomas are considered a mixture of nonneoplastic tissue, which may be indigenous to a different location in the body. As such, they may be epithelial, mesenchymal, or mixed. In the sinonasal region, the following hamartomatous lesions are considered to lie on a spectrum and include respiratory epithelial adenomatoid hamartoma (REAH), chondro-osseous respiratory epithelial adenomatoid hamartoma (COREAH), and nasal chondromesenchymal hamartoma (NCMH). To our knowledge, less than 50 cases of sinonasal hamartomas have been reported in the English literature so far with NCMH being very rare and primarily a tumor in infancy, with only 2 cases reported in individuals older than 16 years of age. We report a highly unusual case of a NCMH in the right maxillary sinus of a 70-year-old female.

Nasal Chondromesenchymal Hamartoma with Skull Base and Orbital Involvement: Case Presentation

Nasal chondromesenchymal hamartoma (NCMH) is a rare benign tumor of the sinonasal tract in children with possible orbit and skull base involvement. We present the 57th published observation of this kind of tumor. A 25-month-old female patient presented with recurrent mass lesion of the sinonasal tract. According to her history, she had feeding difficulties and nasal obstruction since birth. She underwent partial resection at eight months of age via transfacial approach in the local hospital. Due to progression of tumor remnants, a second surgery was performed using an endoscopic endonasal approach resulting in subtotal resection. At 12 months of follow-up, a good postoperative result was observed with no signs of tumor progression despite incomplete resection. Histological and immunohistochemical examination of the biopsy specimens is presented. Comparison of specimens obtained from each of the two surgeries showed a difference in histological patterns. Endoscopic endonasal approach is the mainstay of surgical management. In case of incomplete resection, careful follow-up MRI studies should be recommended.

Selected Diagnostically Challenging Pediatric Soft Tissue Tumors

Many benign and malignant soft tissue tumors in children are challenging and their diagnosis requires knowledge of their vast diversity, histopathological complexity, and immunohistochemical, cytogenetic, and molecular characteristics. The importance of clinical and imaging features cannot be overstated. Soft tissue sarcomas account for 15% of all pediatric malignancies after leukemia/lymphoma, central nervous system tumors, neuroblastoma and Wilms tumor. This article discusses selected challenging pediatric soft tissue tumors with an update on recently described entities.

Nasal Chondromesenchymal Hamartoma (NCMH): a systematic review of the literature with a new case report

BACKGROUND

Nasal chondromesenchymal hamartoma (NCMH) is a very rare, benign tumour of the sinonasal tract usually presenting in infants. We present a systematic review of NCMH cases alongside a case report of an adult with asymptomatic NCMH.

METHODS

A systematic review was conducted in accordance with PRISMA guidelines. A PubMed, EMBASE and manual search through references of relevant publications was used to identify all published case-reports of NCMH. Data was collected from each case-report on: patient demographics, laterality, size and location of NCMH, presentation, co-morbidities, investigations, treatment and follow-up.

RESULTS

The systematic review identified 48 patients (including ours): 33 male, 15 female. Mean age was 9.6 years (range: 1 day-69 years) with the majority aged 1 year or younger at presentation (n = 18). Presentations included: nasal congestion (n = 17), nasal mass (n = 15) and eye signs (n = 12). NCMH also involved the paranasal sinuses (n = 26), orbit (n = 16) and skull-base (n = 14). All patients underwent operative resection of NCMH. A small 2014 case-series found DICER1 mutations in 6 NCMH patients, establishing a link to the DICER1 tumour spectrum.

CONCLUSIONS

NCMH is a rare cause of nasal masses in young children and adults. In light of the newly established link between NCMH and DICER1 mutations surgeons should be vigilant for associated DICER1 tumours, as NCMH may be the 'herald tumour' of this disease spectrum.

Nasal chondromesenchymal hamartomas arise secondary to germline and somatic mutations of DICER1 in the pleuropulmonary blastoma tumor predisposition disorder

Nasal chondromesenchymal hamartoma (NCMH) is a rare nasal tumor that typically presents in young children. We previously reported on NCMH occurrence in children with pleuropulmonary blastoma (PPB), a rare pulmonary dysembryonic sarcoma that is the hallmark neoplasm in the PPB-associated DICER1 tumor predisposition disorder. Original pathologic materials from individuals with a PPB, PPB-associated tumor and/or a DICER1 mutation were centrally reviewed by the International PPB Registry. Paraffin-embedded NCMH tumor tissue was available in three cases. Laser-capture microdissection was used to isolate mesenchymal spindle cells and cartilage in one case for Sanger sequencing of DICER1. Nine patients (5F/4M) had PPB and NCMH. NCMH was diagnosed at a median age of 10 years (range 6-21 years). NCMH developed 4.5-13 years after PPB. Presenting NCMH symptoms included chronic sinusitis and nasal congestion. Five patients had bilateral tumors. Local NCMH recurrences required several surgical resections in two patients, but all nine patients were alive at 0-16 years of follow-up. Pathogenic germline DICER1 mutations were found in 6/8 NCMH patients tested. In 2 of the patients with germline DICER1 mutations, somatic DICER1 missense mutations were also identified in their NCMH (E1813D; n = 2). Three additional PPB patients developed other nasal lesions seen in the general population (a Schneiderian papilloma, chronic sinusitis with cysts, and allergic nasal polyps with eosinophils). Two of these patients had germline DICER1 mutations. Pathogenic germline and somatic mutations of DICER1 in NCMH establishes that the genetic etiology of NCMH is similar to PPB, despite the disparate biological potential of these neoplasms.

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.