So-called congenital-infantile fibrosarcoma: does it exist and what is it?

Abdominal wall congenital infantile fibrosarcoma: A rare case report and literature review

Congenital infantile fibrosarcoma is a rare malignant soft tissue tumor, accounting for less than 1%-2% of childhood cancers. Although it can arise from any body part, an abdominal wall origin is exceptionally rare. This case report presents a case of congenital infantile fibrosarcoma originating from the abdominal wall. To the best of our knowledge, this is only the second reported case of abdominal wall congenital infantile fibrosarcoma. Unlike adult fibrosarcoma, infantile fibrosarcoma has a good prognosis with less metastasis. Early diagnosis and management are critical for improving outcomes in such rare cases.

Long term follow-up of congenital infantile fibrosarcoma of the orbital region

We present the long-term follow-up of a case of periorbital congenital infantile fibrosarcoma (CIFS) treated with chemotherapy and surgery. The tumor was detected on a routine prenatal ultrasound at 30 weeks of gestation and diagnosed via an orbital biopsy day 9 postnatal age. The patient underwent chemotherapy and surgical debulking within the first 3 months of life and has maintained complete tumor remission for 7 years. The case highlights that early recognition and prompt treatment of periorbital CIFS can lead to complete long-term remission of this uncommon malignancy.

Spindle cell sarcoma with KIAA1549-BRAF resembling infantile fibrosarcoma morphologically: A case report and literature review

Infantile fibrosarcoma (IFS) commonly harbors ETS variant transcription factor 6 (ETV6)-neurotrophic receptor tyrosine kinase 3 (NTRK3) fusion. However, the recent accessibility to clinical next-generation sequencing (NGS) has revealed ETV6-NTRK3 negative spindle cell sarcomas resembling IFS morphologically, involving NTRK1/2, MET, RET and BRAF. The present report describes a pediatric case of spindle cell sarcoma with KIAA1549-BRAF resembling IFS morphologically. A 20-month-old female patient was referred to Kobe Children's Hospital (Kobe, Japan) for the treatment of intrathoracic spindle cell sarcoma. Pathologically, the intrathoracic tumor cells were composed of spindle cells with focal hemagiopericytomatous pattern. In immunohistochemistry analysis, the intrathoracic tumor cells focally expressed desmin and WT-1 and were negative for pan-tropomyosin receptor kinase (TRK), S-100 and CD34. Fluorescence in situ hybridization analysis for ETV6 and capicua transcriptional repressor revealed negative split signals. Although the patient was initially diagnosed with IFS morphologically, KIAA1549-BRAF fusion transcript was detected by comprehensive genomic profiling with NGS using intrathoracic tumor tissues and confirmed by reverse transcription-PCR. Chemotherapy induced a reduction in the tumor size. At present, the patient is alive with the disease and has been receiving therapy for 8 months since the initiation of chemotherapy. Review of BRAF-altered spindle cell sarcomas resembling IFS morphologically revealed the inconsistency in immunohistochemical expression patterns and the diversity of BRAF fusion genes and mutations. Therefore, the elucidation of genomic profiling by NGS may assist in making an appropriate diagnosis and selecting novel alternative therapies in ETV6-NTRK3-negative spindle cell sarcomas resembling IFS morphologically.

Comparison of clinical features between patients with bone and soft tissue fibrosarcomas

BACKGROUND AND OBJECTIVES

Fibrosarcomas predominantly arise in soft tissues, but can also develop in bone. Because of their rarity, whether bone development has an impact on clinical features has not been addressed.

METHODS

We included fibrosarcoma patients diagnosed between 1983 and 2016 in the Surveillance, Epidemiology, and End Results database. Differences in clinical features between fibrosarcoma of bone (FS-B) and fibrosarcoma of soft tissue (FS-ST) were investigated.

RESULTS

After excluding patients without information regarding cause of death, site of origin, distant tumor or survival, 1443 patients were included. Of those, 98 patients had FS-B. Patients with FS-B were younger, more frequently male, with fibrosarcomas that more often developed in an extremity and were histologically high-grade. In contrast, no difference in potential to metastasize was observed. Survival was almost equal between FS-B and FS-ST (FS-B/FS-ST: cancer-specific survival, hazard ratio [HR]: 1.2, 95% confidence interval [CI]: 0.8-1.7; overall survival, HR: 1.3, 95% CI: 0.9-1.7).

CONCLUSIONS

Our results clearly indicated that patient backgrounds differed, such as younger age and greater tendencies to affect males, develop in an extremity and show high-grade tumor in patients with FS-B. In contrast, no differences were observed in distant metastatic potential or survival.

Update of pediatric soft tissue tumors with review of conventional MRI appearance-part 1: tumor-like lesions, adipocytic tumors, fibroblastic and myofibroblastic tumors, and perivascular tumors

There are numerous soft tissue tumors and tumor-like conditions in the pediatric population. Magnetic resonance imaging is the most useful modality for imaging these lesions. Although certain soft tissue lesions exhibit magnetic resonance features characteristic of a specific diagnosis, most lesions are indeterminate, and a biopsy is necessary for diagnosis. We provide a detailed update of soft tissue tumors and tumor-like conditions that occur in the pediatric population, emphasizing each lesion's conventional magnetic resonance imaging appearance, using the recently released 5th edition of the World Health Organization Classification of Soft Tissue and Bone Tumors as a guide. In part one of this review, pediatric tumor-like lesions, adipocytic tumors, fibroblastic and myofibroblastic tumors, and perivascular tumors are discussed. In part two, vascular lesions, fibrohistiocytic tumors, muscle tumors, peripheral nerve sheath tumors, tumors of uncertain differentiation, and undifferentiated small round cell sarcomas are reviewed. Per the convention of the WHO, these lesions involve the connective, subcutaneous, and other non-parenchymatous-organ soft tissues, as well as the peripheral and autonomic nervous system.

ALK rearrangements in infantile fibrosarcoma-like spindle cell tumours of soft tissue and kidney

AIMS

Recurrent alterations in receptor tyrosine kinase (RTK) and downstream effectors are described in infantile fibrosarcoma (IFS)/cellular congenital mesoblastic nephroma (cCMN) and a subset of spindle cell sarcomas, provisionally designated 'NTRK-rearranged' spindle cell neoplasms. These two groups of tumours demonstrate overlapping morphologies and harbour alterations in NTRK1/2/3, RET, MET, ABL1, ROS1, RAF1 and BRAF, although their relationship is not fully elucidated. We describe herein a cohort of paediatric tumours with clinicopathological features not typical for inflammatory myofibroblastic tumour, but rather with similarities to cCMN/IFS harbouring ALK fusions.

METHODS AND RESULTS

Clinicopathological features were assessed and partner agnostic targeted RNA sequencing on clinically validated platforms were performed. Tumours occurred in patients aged from 2 to 10 years (median age 2 years) with a 2:2 male to female ratio and an average size of 8.4 cm. Two tumours arose in soft tissues and two in the kidney. Morphological features included spindle to ovoid cells arranged in long fascicles or haphazardly within a myxoid to collagenised stroma; a subset of cases had either dilated, ectatic vessels or focal perivascular hyalinosis. By immunohistochemistry, all cases tested showed cytoplasmic expression of anaplastic lymphoma kinase (ALK) and one case demonstrated co-expression of CD34 and S100.

CONCLUSIONS

This series of ALK-rearranged IFS-like tumours expands the spectrum of targetable kinases altered in these tumours and reinforces the potential overlap between IFS/cCMN-like tumours and the provisional entity of 'NTRK-rearranged' spindle cell neoplasms.

NTRK-Rearranged soft tissue neoplasms: A review of evolving diagnostic entities and algorithmic detection methods

The spectrum of tumors with NTRK1/2/3 rearrangements has expanded with widespread use of next generation sequencing (NGS) technology. For many years it was known that a majority of infantile fibrosarcomas (IFS), and their counterpart in the kidney, cellular congenital mesoblastic nephroma, contain the recurrent ETV6-NTRK3 fusion. Sequencing RNA transcripts from IFS and their morphologically similar counterparts in older children and adults has shown rearrangements with other 5' partners combined with NTRK1, NTRK2, and NTRK3 can also occur. For those tumors occurring outside of the infant age group, this has resulted in a proposed new diagnostic entity of "NTRK-rearranged spindle cell neoplasm." The clinical behavior of NTRK rearranged soft tissue tumors varies, though most show localized disease with rare metastases. The pathology of NTRK rearranged tumors exists on a spectrum, with overlapping features of classic infantile fibrosarcoma, lipofibromatosis, and malignant peripheral nerve sheath tumor. In this tumor spectrum, clinical and pathologic predictive factors are largely still to be determined, with no clear association between histologic grade and severity of disease. Of critical importance is detection of the NTRK rearrangement in order to guide treatment in patients with unresectable and metastatic disease. While resection is the definitive treatment, these tumors do show response to targeted TRK kinase inhibitors. Multiple detection methods are available, including immunohistochemistry, FISH, and next generation sequencing, which each have their merits and potential pitfalls. We aim to review the clinical characteristics and histomorphology of mesenchymal tumors with NTRK rearrangements as well as discuss molecular detection methods and diagnostic algorithms specific for soft tissue tumors.

Challenges in the Diagnosis of Pediatric Spindle Cell/Sclerosing Rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is the most common pediatric soft tissue sarcoma, representing approximately 40% of all pediatric soft tissue sarcomas. The spindle cell/sclerosing subtype of RMS (SSRMS) accounts for roughly 5% to 10% of all cases of adult and pediatric RMS. Historically, SSRMS were described as paratesticular tumors with an excellent outcome. However, more recent studies have identified unique molecular subgroups of SSRMS, including those with MYOD1 mutations or VGLL2/NCOA2 fusions, which have widely disparate outcomes. The goal of this article is to better describe the biological heterogeneity of SSRMS, which may allow the pathologist to provide important prognostic information.

Cervical Infantile Fibrosarcoma: a rare cause of paediatric parapharyngeal neck mass

Soft tissue tumors are not uncommon in childhood and comprise entities that range from common to very rare malignancies. Infantile fibrosarcoma (IFS) is a rare pediatric malignancy mainly seen in the first two years of life. The data about the incidence of infantile fibrosarcoma occurring in the neck in the Indian subcontinent is scarce. To the best of our knowledge, only one case of infant cervical IFS has been reported previously in the Indian subcontinent. We present another case of an eight-year-old male patient with a rapidly growing mass on the left side of the neck. He was successfully treated with a combined modality of surgery and chemotherapy with a good outcome. Among the soft tissue tumors of childhood, IFS is a rare entity. It has a good prognosis and lesser chance of distant metastasis as compared to adult fibrosarcoma. Though surgical excision is the mainstay of treatment, chemotherapy also has a significant role in the treatment of primary tumor and metastasis. We discuss the stated case to bring to the notice this uncommon cause, which can be considered as a differential diagnosis of upper cervical swellings. A better understanding of this entity would help in early diagnosis and aggressive treatment, reducing the overall morbidity and mortality.

The impact of local control in the treatment of children with advanced infantile and adult-type fibrosarcoma: Experience of the cooperative weichteilsarkom studiengruppe (CWS)

BACKGROUND AND OBJECTIVES

This study aims at examining the potential survival benefits of primary versus secondary surgery of children diagnosed with advanced infantile (iFS) and adult-type fibrosarcoma (aFS).

METHODS

Treatment and outcome of 89 children with FS treated within prospective Cooperative Studiengruppe (CWS) trials (1981-2016) were analyzed retrospectively.

RESULTS

Localized disease (LD) was diagnosed in 87 patients: 64/66 patients with iFS (≤2 years) and 23 with aFS (>2 ≤ 18 years). Two patients (iFS) had metastatic disease. Resection was the mainstay of therapy of patients with LD resulting in microscopically complete (R0, IRS group I) (n = 29/87, 33%), microscopically incomplete (R1, IRS group II) (n = 17/87, 20%) and macroscopically incomplete (R2, IRS group III) (n = 41/87, 47%). Advanced LD (IRS group III) was present in 32/64 (50%) patients with iFS and in 9/23 (39%) with aFS. Chemotherapy was added predominantly in patients with advanced disease and an assessable objective response to CHT was seen in 71% iFS and 75% aFS. The 5-year event-free survival (EFS) of patients with iFS and aFS was 81% (±10, 95% CI) and 70% (±19, 95% CI) (p = 0.24); the 5-year overall survival (OS) was 98% (±3, 95% CI) and 82% (±16, 95% CI) (p = 0.02). Primary resection was no prognostic factor. Secondary R0/ R1 resection in patients with advanced disease improved 5-year EFS and OS in aFS (p = 0.002 and p = 0.000) but not in infants.

CONCLUSIONS

Secondary resection improves outcome in advanced aFS but not in infants. Mutilating surgery in infants should be avoided.

TYPE OF STUDY AND LEVEL OF EVIDENCE

Treatment study: patients were enrolled in five prospective studies and one registry, prognosis study: retrospective study.

LEVEL OF EVIDENCE

II/ III.

MINI-ABSTRACT

Fibrosarcoma is a very rare malignant tumor. Little is known about differences of local treatment of advanced infantile and adult-type. Data of 89 patients registered in five prospective trials and one registry of the Cooperative Weichteilsarkom Studiengruppe (CWS) (1981-2016) were analyzed.

Soft Tissue Special Issue: Fibroblastic and Myofibroblastic Neoplasms of the Head and Neck

Fibroblastic and myofibroblastic neoplasms of the head and neck encompass a group of rare tumor types with often overlapping clinicopathologic features that range in biologic potential from benign to overtly malignant. Even neoplasms with no metastatic potential may provide significant therapeutic challenges in this region due to the unique anatomy of the head and neck. This review will cover the following entities, highlighting important clinical aspects of each neoplasm and then focusing on their characteristic histomorphology, immunophenotype, and molecular alterations: nodular and cranial fasciitis, fibrous hamartoma of infancy, nasopharyngeal angiofibroma, nuchal-type and Gardner fibromas, desmoid fibromatosis, dermatofibrosarcoma protuberans and giant cell fibroblastoma, solitary fibrous tumor, inflammatory myofibroblastic tumor, low-grade myofibroblastic sarcoma, infantile fibrosarcoma, low-grade fibromyxoid sarcoma, and sclerosing epithelioid fibrosarcoma. While some of these neoplasms characteristically arise in the head and neck, others are rarely described in this anatomic region and may therefore be particularly difficult to recognize. Distinction between these entities, however, is crucial, particularly as the molecular pathogenetic basis for these neoplasms are being rapidly elucidated, in some instances allowing for targeted therapeutic approaches.

Expanding the Spectrum of Pediatric NTRK-rearranged Mesenchymal Tumors

Pediatric mesenchymal tumors harboring variant NTRK fusions (ETV6-negative) are being increasingly described; however, the histologic and clinical features of these variant NTRK tumors and their relationship to classic infantile fibrosarcoma are not well characterized. A better understanding of the clinicopathologic features of these tumors is necessary, and would aid in both early diagnosis and treatment. Therefore, the aim of this study was to characterize a series of pediatric NTRK-rearranged mesenchymal tumors, including classic ETV6-NTRK3 fused tumors and tumors with variant (non-ETV6) NTRK fusions. The clinical features, morphology, immunophenotype, and genetics of 12 classic ETV6-NTRK3 fused infantile fibrosarcoma and 18 variant NTRK-rearranged mesenchymal tumors were evaluated. For both classic and variant groups, the age at diagnosis ranged from birth to 15 years (median, 4 mo) with no sex predilection; the most common sites involved were the extremities and trunk. The rate of local recurrence and metastasis were not significantly different (recurrence rate: 11% classic, 40% variant; metastatic rate: 18% classic, 25% variant). Classic and variant NTRK tumors had an overlapping spectrum of histologic features, containing haphazardly arranged primitive cells in a myxoid background and/or spindle cells in long fascicles. Both groups showed diffuse pan-TRK expression by immunohistochemistry. Otherwise, the immunoprofile was nonspecific, but similar between both groups. No statistical difference was seen in any clinicopathologic feature between the classic ETV6-NTRK3 and variant fusion cohorts. Pediatric NTRK-rearranged mesenchymal tumors with both classic and variant fusions likely represent a spectrum of disease with shared, recognizable cliniopathologic features.

Fibrosarcoma of the ethmoid sinus: A rare entity

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Ethmoidal fibrosarcoma is an extremely rare tumor.

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Mostly misdiagnosed because of none specifics symptoms, in this case patient didn’t complaint any nasal symptom.

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Treatment is not codified and prognosis is unknown.

Introduction

Ethmoidal fibrosarcoma is an extremely rare tumor which represent less than one percent of all malignancies in this anatomical area, the case of a 13-year-old is reported here.

Presentation of case

A 13-year-old boy, his medical history was marked exclusively before presented to our hospital by an exophthalmia. Rhinoscopic examination showed well-defined pink mass at the level of ethmoid. Computed tomography was performed to showed local and regional extension. Treatment was an endoscopic excision of the tumor using a navigation system. The final diagnosis was made on pathologic examination. Radiotherapy was recommended by multidisciplinary staff but the patient refused.

Discussion

These tumors occur in extremities most frequently and Ethmoidal localization is extremely rare and have no specifics symptoms, so the rhinoscopic examination is necessary for any chronic nasal symptom. Its treatment is not codified because of its rarity and its prognosis is unknown.

Conclusion

It’s important knowledge about this pathology because of its rarity and its therapeutic and prognostic difficulties.

Congenital infantile fibrosarcoma of the glabella: Nuances of achieving surgical cure without cosmetic or functional deformity

Congenital Infantile Fibrosarcoma is a rare neoplasm that typically presents during the first year of life, but uncommonly in the head and neck. We report a six-day old male presenting with an expanding mass of the right glabella associated with visual field obstruction. The patient underwent a two-staged procedure for surgical removal of the tumor due to the initially unclear pathologic diagnosis of the tumor, combined with the desire to close the defect while incurring minimal aesthetic or functional deformity. We describe this patient's postnatal presentation and curative surgical management and review the relevant literature to date.

Recurrent EML4-NTRK3 fusions in infantile fibrosarcoma and congenital mesoblastic nephroma suggest a revised testing strategy

Infantile fibrosarcoma and congenital mesoblastic nephroma are tumors of infancy traditionally associated with the ETV6-NTRK3 gene fusion. However, a number of case reports have identified variant fusions in these tumors. In order to assess the frequency of variant NTRK3 fusions, and in particular whether the recently identified EML4-NTRK3 fusion is recurrent, 63 archival cases of infantile fibrosarcoma, congenital mesoblastic nephroma, mammary analog secretory carcinoma and secretory breast carcinoma (tumor types that are known to carry recurrent ETV6-NTRK3 fusions) were tested with NTRK3 break-apart FISH, EML4-NTRK3 dual fusion FISH, and targeted RNA sequencing. The EML4-NTRK3 fusion was identified in two cases of infantile fibrosarcoma (one of which was previously described), and in one case of congenital mesoblastic nephroma, demonstrating that the EML4-NTRK3 fusion is a recurrent genetic event in these related tumors. The growing spectrum of gene fusions associated with infantile fibrosarcoma and congenital mesoblastic nephroma along with the recent availability of targeted therapies directed toward inhibition of NTRK signaling argue for alternate testing strategies beyond ETV6 break-apart FISH. The use of either NTRK3 FISH or next-generation sequencing will expand the number of cases in which an oncogenic fusion is identified and facilitate optimal diagnosis and treatment for patients.

Infantile Fibrosarcoma: Retrospective Analysis of Eleven Patients

Aims and background

Infantile fibrosarcomas are soft tissue sarcomas that are diagnosed at or soon after birth. In the present study, we retrospectively evaluated clinical characteristics, treatment modalities and outcome of patients diagnosed with infantile fibrosarcoma at our institution.

Methods

A retrospective review was conducted to evaluate demographic characteristics, presenting features, type and timing of surgery, other treatment modalities and survival characteristics.

Results

Nine males and 2 females were diagnosed with infantile fibrosarcoma between 1970–2008. The initial surgical procedure was subtotal resection in 4 patients, gross-total resection in 3 and biopsy in 4. Neoadjuvant chemotherapy was given to 10 patients. Three patients died, one for the disease and 2 from complications of therapy. Eight patients are under follow-up with no evidence of disease for 1.3 to 13.5 years. None of the patients in the series underwent amputation.

Conclusions

Owing to the chemosensitive nature of the tumor and possibility of spontaneous regression, neoadjuvant chemotherapy should be considered to prevent extensive or mutilating surgery.

Infantile NTRK-associated Mesenchymal Tumors

Pediatric fibroblastic/myofibroblastic lesions are a relatively common group of tumors with varying morphologies, for which the molecular mechanisms are becoming increasingly well characterized. Congenital infantile fibrosarcoma (CIFS), perhaps the most well studied of these lesions is characterized by a recurrent ETV6-NTRK3 gene fusion. However, a notable subset of locally aggressive congenital/infantile soft tissue lesions with similar morphologic features to CIFS, have not to-date, shown evidence of any canonical molecular aberration. We describe 6 patients with mesenchymal tumors composed of infiltrative fibroblastic/myofibroblastic tumor cells and showing a morphologic spectrum of features much analogous to that previously described in CIFS but without ETV6 fusion transcripts. These tumors lacked a uniform immunoprofile, but showed variable expression of CD34, S100, smooth muscle actin, and CD30. All patients first developed a mass in infancy (≤2 months of age). Using next-generation DNA sequencing, TMP3-NTRK1 fusions were identified in 4 cases, an LMNA-NTRK1 fusion in one case, and a variant EML4-NTRK3 fusion in one case. Similar to infantile fibrosarcoma, these tumors were locally aggressive (with local recurrences if incompletely excised) and rarely metastasized (lung metastases in one patient). Proper identification of these tumors including investigation for NTRK family gene rearrangements is essential for diagnostic accuracy, as well as for clinical management decisions. Given the morbidity associated with radical resection of large soft tissue tumors, children with unresectable, recurrent, and/or metastatic disease may benefit from treatment with NTRK targeted therapies.

Congenital intestinal fibrosarcoma with rapid recurrence requiring adjuvant chemotherapy

A total of 16 cases of congenital fibrosarcoma have been reported from 1975 to March 2015. Five of the 16 had abnormal fusion between erythroblast transformation specific translocation variant 6 and neurotrophin recptor gene neurotrophic tyrosine kinase, receptor, type 3 (ETV6-NTRK3); in another five out of 16 this was absent, and six were not tested. All were managed by surgical resection but none involved metastasis. Herein we report the case of a newborn baby girl with congenital fibrosarcoma negative for ETV6-NTRK3 gene fusion, who presented with ileal perforation and positive resection margin. She had rapid recurrence with lymph node metastasis treated with postoperative chemotherapy. There was no further recurrence at >3 years of follow up.

Molecular Markers in Bone and Soft-Tissue Tumors

Many sarcomas such as osteosarcoma have complex molecular compositions and behaviors that make standardized treatment difficult for patients with these tumors. Chromosomal translocations are noted in specific bone and soft-tissue sarcomas, and there are molecular tests (polymerase chain reaction [PCR] and fluorescence in situ hybridization [FISH]) used for accurate diagnosis. The translocations noted in sarcomas may allow future therapeutic targeting.

Primitive Spindle Cell Neoplasm of Ileum with Extensive Heterotopic Cartilage, Presenting as Acute Abdomen in a 6-Day-Old Neonate

Neonatal intestinal masses with spindle cell morphology have broad differential diagnoses and require a multidisciplinary approach to make the final diagnosis. Spindle cell masses with heterotopic cartilage in the gastrointestinal tract are very rare, and, to our knowledge, have not previously been reported in the neonate. Here we present a case of intestinal primitive spindle cell neoplasm with extensive heterotopic cartilage that manifested initially as acute abdomen in a 6-day-old term infant. Plain radiography demonstrated pneumoperitoneum, prompting diagnostic laparotomy that identified a perforated mass involving the midileum. Histologic and immunohistochemical examination demonstrated an infiltrative spindle cell tumor most compatible with infantile fibrosarcoma (IFS) by a process of exclusion, with nodules of mature heterotopic cartilage. Additional staging studies did not reveal any evidence of residual or metastatic disease. Recognition of this rare variant of IFS will aid in differentiation from other neonatal intestinal mesenchymal tumors.

Chest Wall Infantile Fibrosarcomas- A Rare Presentation

Infantile fibrosarcoma is rare and represents less than 1 % of all childhood cancers. Commonly, it arises in the limbs followed by the trunk and head and neck. We present a rare case of infantile fibrosarcoma of trunk at two different sites in a newborn with brief review of the relevant literature.

Conservative strategy in infantile fibrosarcoma is possible: The European paediatric Soft tissue sarcoma Study Group experience

BACKGROUND

Infantile fibrosarcoma (IFS) is a very rare disease occurring in young infants characterised by a high local aggressiveness but overall with a favourable survival. To try to reduce the total burden of therapy, the European pediatric Soft tissue sarcoma Study Group has developed conservative therapeutic recommendations according to initial resectability.

MATERIAL AND METHODS

Between 2005 and 2012, children with localised IFS were prospectively registered. Initial surgery was suggested only if possible without mutilation. Patients with initial complete (IRS-group I/R0) or microscopic incomplete (group II/R1) resection had no further therapy. Patients with initial inoperable tumour (group III/R2) received first-line vincristine-actinomycin-D chemotherapy (VA). Delayed conservative surgery was planned after tumour reduction. Aggressive local therapy (mutilating surgery or external radiotherapy) was discouraged.

RESULTS

A total of 50 infants (median age 1.4 months), were included in the study. ETV6-NTRK3 transcript was present in 87.2% of patients where investigation was performed. According to initial surgery, 11 patients were classified as group I, 8 as group II and 31 as group III. VA chemotherapy was first delivered to 25 children with IRS-III/R2 and one with IRS-II/R1 disease. Response rate to VA was 68.0%. Mutilating surgery was only performed in three cases. After a median follow-up of 4.7 years (range 1.9-9.0), 3-year event-free survival and overall survival were respectively 84.0% (95% confidence interval [CI] 70.5-91.7) and 94.0% (95% CI 82.5-98.0).

CONCLUSIONS

Conservative therapy is possible in IFS as only three children required mutilating surgery, and alkylating or anthracycline based chemotherapy was avoided in 71.0% of patients needing chemotherapy. VA regimen should be first line therapy in order to reduce long term effects.

Congenital-infantile fibrosarcoma of the ileocecal region: the first case presentation

Infantile fibrosarcoma is a very rare soft tissue tumor that originates most commonly in the body and extremities. We present a neonate with an infantile fibrosarcoma that originated in the ileocecal region and was detected incidentally without symptoms. This is the first case of fibrosarcoma reported in the ileocecal region.

Infantile fibrosarcoma of ethmoid sinus, misdiagnosed as an adenoid in a 5-year-old child

Infantile fibrosarcoma of head and neck is rare and the presence of this tumor in ethmoid sinus is even more uncommon. To the best of our knowledge, <5 cases have been reported in the last 20 years in the English literature, so far, only one of which has been infantile type in a 15 months old girl. In this case report, we will explain our experience with a rare case of infantile fibrosarcoma originating from ethmoid sinus in a 5-year-old boy who presented with dyspnea and epistaxis. After biopsy, it was diagnosed as fibrosarcoma of sinus origin.

Primary Pulmonary Fibrosarcoma With Bone Metastasis: a Successful Treatment With Post-Operation Adjuvant Chemotherapy

Introduction:

Pulmonary fibrosarcoma has been an extremely rare tumor in children. Wide surgical resection of infantile fibrosarcoma would be the treatment of choice.

Case Presentation:

Post-operative chemotherapy has shown the benefit in the cases of residual disease after initial surgery and metastatic disease in the literature. We have presented the case of a 70-days old male child with primary infantile fibrosarcoma of the left lung and distant metastasis of skull.

Conclusions:

The aim of this publication was to highlight the role of adjuvant chemotherapy to improve outcome of infantile fibrosarcoma with residual tumor and / or metastatic disease.

Congenital infantile fibrosarcoma: review of imaging features

BACKGROUND

Fibrosarcoma is a rare tumor in children with limited information on imaging features of these tumors in the literature.

OBJECTIVE

To retrospectively review the imaging features of histologically proven congenital infantile fibrosarcoma.

MATERIALS AND METHODS

The list of histologically confirmed congenital infantile fibrosarcomas between November 1999 and June 2013 was obtained from the oncology-pathology database. Imaging features and pathology reports of these tumors were reviewed. Patient charts were reviewed and clinical features, management and outcomes were recorded.

RESULTS

During the study period, 13 children (9 girls and 4 boys; age range: 0 day-16 months, median age: 2.5 months) with congenital infantile fibrosarcomas were available for complete radiological review. The translocation (t[12;15]) was present in 11/13 (84.6%) and absent in 2/13. Eight/thirteen (61.5%) tumors were located in extremities (5 in lower and 3 in upper), 3/13 in thoracolumbar paraspinal regions, and one each in abdomen and sternocleidomastoid muscle. Imaging features included iso- to hyperintensity on T1-W, hyperintensity on T2-W as compared to skeletal muscles and heterogeneous enhancement. Six (37.5%) tumors showed hemorrhagic components and 2 (15.4%) showed low intensity foci. None of the patients had evidence of regional or distant metastases at diagnosis. Management included surgical resection only (1/13) and combined surgery and chemotherapy (10/13). Overall survival was 100% with a median follow-up of 49.3 months.

CONCLUSION

Congenital infantile fibrosarcoma has nonspecific imaging characteristics but should be high on the differential diagnosis in a soft-tissue tumor presenting in infancy, located in an extremity and showing tumoral hemorrhage. Patients have a favorable outcome.

Clinical management of infantile fibrosarcoma: a retrospective single-institution review

BACKGROUND

Infantile fibrosarcoma (IFS) is an uncommon soft-tissue sarcoma. Here we review our experience treating this tumor.

PATIENTS AND METHODS

We retrospectively reviewed records of patients with IFS treated at St. Jude Children's Research Hospital between 1980 and 2009.

RESULTS

We identified 15 patients, 8 girls and 7 boys; 13 white and 2 black. Median age at diagnosis was 3 months. Primary sites included the leg (n = 3), chest wall (n = 2), foot (n = 2), and one each in the tongue, occipital region, axilla, parascapular region, arm, forearm, retroperitoneum, and thigh. All patients underwent resection; 11 upfront surgery, and 4 delayed. Complications included loss of the posterior tibial nerve and artery, axillary vein, biceps, pectoralis major, gallbladder, and transverse/sigmoid sinus. Eight received chemotherapy and three radiotherapy. Seven experienced local recurrence and three lung metastasis. Median follow-up was 65 months. At the time of the review, 12 patients were alive and 3 had died. All deaths were in patients older than 1 year at diagnosis with an axial primary site.

CONCLUSIONS

Non-mutilating surgery should be the primary treatment for IFS. Neoadjuvant chemotherapy is indicated when upfront resection is unfeasible. Patients with positive surgical margins should receive adjuvant chemotherapy. Radiotherapy is indicated for axial primary sites where complete resection is impossible.

Neonatal soft tissue sarcomas

Soft tissue tumors in very young children pose diagnostic and therapeutic challenges. Vascular tumors are the most prevalent soft tissue neoplasms in the neonatal period. They are generally benign tumors, but may exhibit aggressive behaviour and cause life-threatening complications. Fibroblastic tumors of intermediate prognosis, more prevalent in very young children (especially infantile fibrosarcoma), are locally aggressive. Since metastases are unusual in this group of tumors, complete surgical resection is generally curative. However, these tumors often present a therapeutic challenge because of the location which makes complete surgical resection difficult. Among the malignant soft tissue tumors, rhabdomyosarcoma is most frequent. It is an aggressive high-grade tumor, with local invasiveness and a propensity to metastasize. These tumors respond to chemotherapy and radiotherapy. Neonates with rhabdomyosarcoma seem to have a worse prognosis than in older age groups. This may be a result of inappropriate dosing of chemotherapeutic agents and decreased use of radiation therapy among other factors.

Fibroblastic and myofibroblastic tumors in children and adolescents

Fibroblastic and myofibroblastic tumors in children and adolescents are a relatively common group of soft tissue proliferations that range from reactive to hamartomatous to neoplastic, with a full spectrum of benign, intermediate, and malignant neoplasms. These lesions are diagnostically challenging because of morphologic and immunohistochemical overlap, despite significant clinical, genetic, and prognostic differences. The fibromatoses are a major subgroup, and all types of fibromatoses can occur in the 1st 2 decades of life. Intermediate and malignant fibroblastic-myofibroblastic tumors are an important group that includes variants of fibrosarcoma and other tumors with recurrent cytogenetic or molecular genetic abnormalities and low metastatic potential. Pathologic examination is enhanced by adjunct techniques, such as immunohistochemistry, cytogenetics, and molecular genetics, although morphology provides the ultimate criteria for a specific diagnosis. This article reviews the clinicopathologic features of fibroblastic and myofibroblastic tumors with an emphasis on the unique aspects of these neoplasms in children and adolescents, the use of diagnostic adjuncts, and differential diagnoses.

Congenital-infantile fibrosarcoma masquerading as sacrococcygeal teratoma

Infantile fibrosarcoma is rare and represents less than 1% of all childhood cancers. Commonly, it arises in the limbs followed by the trunk and head and neck. We report a rare case of infantile fibrosarcoma masquerading as sacrococcygeal teratoma in a newborn. The literature on the subject is also reviewed.

Congenital infantile fibrosarcoma of the forearm

Congenital infantile fibrosarcoma is a rare soft tissue neoplasm in the infant of which only a few cases are reported as congenital. This tumor has a rapid growth and extensive local invasion, but metastasis rarely occurs. Distal extremities involvement is more common and metastasis are rare. We report a case of a congenital infantile fibrosarcoma of the forearm, which was initially confused with a hemangioma, treated successfully by surgical resection.

Unusual presentation of congenital infantile fibrosarcoma in seven infants with molecular-genetic analysis

Congenital infantile fibrosarcoma (CIFS) is a rare mesenchymal tumor that primarily presents in the soft tissue of the distal extremities and occasionally in unusual locations such as the lung and retroperitoneum. Herein, we report seven cases of unusual presentations of CIFS. These cases include three in the lungs, one in the retroperitoneum with cord compression, one in the posterior trunk, one in the heart, and one infratemporal involving the sphenoid bone. All tumors demonstrated CIFS's characteristic t(12;15)(p13;q25) and associated ETV6-NTRK3 gene fusion. One of the three lung cases was previously reported as primary bronchopulmonary fibrosarcoma (PBPF), but molecular analysis of the paraffin embedded tissue revealed the ETV6-NTRK3 gene fusion consistent with CIFS. We show that CIFS may occur in unusual sites including visceral locations, and we propose that neoplasms displaying the ETV6-NTRK3 gene fusion represent the visceral components of CIFS.

Primitive myxoid mesenchymal tumor of infancy: a report of a further case with locally aggressive behavior

We report a case of an 8-month-old child with a primitive myxoid mesenchymal tumor of infancy arising in the thenar eminence. The lesion recurred after conservative excision and was ultimately nonresponsive to chemotherapy, necessitating partial amputation. The patient remains free of disease 5 years after this radical surgery. This is the 1st report of such a tumor since it was initially described by Alaggio and colleagues in 2006. The pathologic differential diagnosis is discussed.

Primitive myxoid mesenchymal tumor of infancy in a preterm infant

Primitive myxoid mesenchymal tumor of infancy is a recently recognized entity that has been added to the differential diagnosis of myxoid tumors of the soft tissue. Few cases have been reported of this entity in the literature, but none presenting in a preterm infant. We present the case and clinical course of a preterm boy with a primitive myxoid mesenchymal tumor of infancy that occurred following excision of a congenital juvenile xanthogranuloma.

Pathology of the thoracic wall: congenital and acquired

This review aims to cover the main congenital and acquired lesions that arise in the thoracic wall of infants and children. Imaging often plays an essential role in the evaluation of symptomatic and asymptomatic thoracic wall abnormalities. The use of appropriate imaging modalities for each condition will be addressed, as well as the range of benign and malignant conditions that can occur.

The Spectrum of Pediatric Fibroblastic and Myofibroblastic Tumors

Fibroblastic and myofibroblastic tumors in neonates, infants, and children provide a diagnostic dilemma in surgical pathology due to their relative rarity and similarity in appearances. These tumors may be congenital or occur early during the first years of life or later during the first and second decades of life. The morphologic, immunocytochemical, ultrastructural, cytogenetic, and molecular features of the more "common" pediatric fibroblastic and myofibroblastic tumors are reviewed. In addition, the importance of a multimodal approach to tumor diagnosis is emphasized, with correlation with treatment and outcome differences among these unique fibroblastic and myofibroblastic tumors. The importance of providing an accurate diagnosis with pediatric fibroblastic and myofibroblastic tumors cannot be overstated, because treatment, prognosis, follow-up, and outcome are based on the initial assessment of these fascinating, but oftentimes, perplexing tumors.

Infantile fibrosarcoma successfully treated with chemotherapy, with occurrence of calcifying aponeurotic fibroma and pleomorphic/spindled celled lipoma at the site 12 years later

The treatment of infantile fibrosarcoma has traditionally been wide resection. Chemotherapy has been investigated as an adjuvant and primary treatment in cases in which surgery would cause unacceptable morbidity. Recurrences normally occur within a year of completion of the chemotherapy and display the same histology. We present a child with an infantile fibrosarcoma of the elbow, successfully treated with chemotherapy alone, who developed a calcifying aponeurotic fibroma and a spindle cell/pleomorphic lipoma at the tumor site 12 years later.

Congenital fibrosarcoma with a novel complex 3-way translocation t(12;15;19) and unusual histologic features

Congenital mesenchymal tumors are diagnostically challenging as they are rare and may feature overlapping patterns between several benign, low-grade, and tumors of intermediate malignancy, including myofibromatosis, myofibroma/hemangiopericytoma, congenital fibrosarcoma, and inflammatory myofibroblastic tumor. Their immunophenotype is either silent or minimally expressive, and their ultrastructural features are generically consistent with "fibroblastic/myofibroblastic" differentiation. Cytogenetic analysis allows refined diagnoses, improved classifications, and bettering of our therapeutic armamentarium. However, genotype/phenotype correlations continue rendering novel findings that must be examined for their potential value in diagnosis and treatment. We describe a retroperitoneal congenital fibrosarcoma with an unusually bland histopathology and novel 3-way t(12;15;19) translocation involving chromosome bands 12p13.2, 15q25.3, and 19p13.1, associated with trisomies 8, 11, and 20. Fluorescence in situ hybridization showed one fusion signal in the normal chromosome 12p13.2 and break-apart 3'ETV6 and 5'ETV6 signals in the rearranged 12p13.2 and 15q25.3, respectively. The importance of molecular diagnosis and genotype-phenotype correlations is emphasized.

Morphologic Overlap between Infantile Myofibromatosis and Infantile Fibrosarcoma: A Pitfall in Diagnosis

Infantile myofibromatosis (IM) is a distinctive mesenchymal disorder with different clinical forms, including solitary, multicentric, and generalized with visceral involvement. A wide morphologic spectrum is encountered, with the extremes resembling congenital infantile fibrosarcoma (CIFS) and infantile hemangiopericytoma. We report a series of lesions with mixed features of CIFS and IM and compare them in order to further define their clinicopathologic features and the significance of the so-called composite fibromatosis. Seven lesions with unusual overlapping morphologic "composite" features of both IM and CIFS were selected from a series of 106 myofibroblastic lesions. Three cases classified as composite infantile myofibromatoses (COIM) were highly cellular tumors with a diffuse growth of primitive mesenchymal cells and focal features of IM combined with areas resembling infantile fibrosarcoma (IF). Four cases were classified as IF. Three of these exhibited a biphasic pattern with foci resembling IM, including whorls of primitive and spindle cells and perivascular and intravascular projections of myofibroblastic nodules, and the 4th had a close histologic resemblance to a primitive, immature IM. With reverse transcriptase polymerase chain reaction, the ETV6-NTRK3 transcript was absent in 3 COIM and was detected in 3 CIFS; the other CIFS had typical cytogenetic aberrations. On the basis of currently available information, COIM represents a morphologic variant of IM that can mimic IF. Careful histologic evaluation to detect the typical features of IM is essential to avoid classification as IF. Molecular analysis for the ETV6-NTRK3 gene fusion is an important diagnostic tool in this group of lesions.

Primary colonic congenital infantile fibrosarcoma presenting as meconium peritonitis

Congenital infantile fibrosarcoma is a rare soft tissue malignancy that occurs in both axial and extremity locations. We report a case of this tumor arising from the left colon in a newborn presenting with an intrauterine perforation and meconium peritonitis.

Application of immunohistochemistry to soft tissue neoplasms

CONTEXT

Soft tissue tumors are composed of numerous and complex diagnostic entities. Because of this complexity and the recognition of an intermediate malignancy category including some tumors with a deceptively bland histologic appearance, soft tissue tumors may represent a major diagnostic challenge to the general practicing pathologist.

OBJECTIVE

To correctly diagnose soft tissue tumors with the ancillary use of immunohistochemistry.

DATA SOURCES

Review of the current literature with emphasis on those tumors for which immunohistochemistry has proven to be particularly useful.

CONCLUSIONS

Immunohistochemistry plays an important role in the diagnosis of soft tissue tumors. One of its major utilities is to correctly identify a tumor as being of mesenchymal or nonmesenchymal origin. Once mesenchymal origin has been established, histologic subtyping according to specific cell lineage may be achieved with the use of lineage-specific markers. Tumors of uncertain cell lineage and tumors with primitive small round cell morphology are often characterized by a unique immunohistochemical phenotype. In this group of tumors, immunohistochemistry is most widely applied and is of greatest value. Despite the rapid development of molecular genetic techniques, immunohistochemistry still remains the most important diagnostic tool in the diagnosis of soft tissue tumors aside from recognition of morphologic features and clinical correlation.