Non-resectable congenital tumors with the ETV6-NTRK3 gene fusion are highly responsive to chemotherapy

Congenital mesoblastic nephroma: review of current management and outcomes in a single centre

BACKGROUND

Congenital mesoblastic nephroma (CMN) is a rare tumour of the kidney with an overall excellent prognosis. Once considered a benign tumour, it is now recognized to carry a risk of recurrence and metastases with subsequent poor outcomes. The potential for genetic aberrations such as ETV6-NTRK3 fusion raises the potential for targeted treatments in certain patients. The optimum mode and frequency of surveillance is unclear. This study aims to assess this institution's experience with CMN and long-term outcomes.

METHODS

A single centre retrospective review was performed of all confirmed cases of CMN between October 2001 and January 2021.

RESULTS

Nine cases of CMN in patients under 12 months of age were identified. The histopathology, management and outcomes of these patients are discussed.

CONCLUSION

CMN overall has a very good prognosis, but a subgroup does exist that will have poor outcomes. It is difficult to accurately identify this group to target adjuvant therapy.

Case report: A rare case of congenital non-metastatic low-grade fibrosarcoma of the pleura in a 6-month-old infant manifested as pneumonia

Introduction and importance

Congenital Infantile fibrosarcoma is a rare tumor in children and accounts for only 10 % of various malignant tumors in this age group. Manifestations vary according to the site of occurrence. Symptoms of the tumor located in unusual places can be misleading and obscure the actual diagnosis, which in turn may waste precious effort and time until the correct diagnosis is established. Infant malignancies should be considered to reduce the morbidity and mortality associated with this pathology.

Case presentation

We present the case of a 6-month-old infant, who was admitted to our hospital with a one-month history of high fever and dry cough, with no improvement in symptoms after treatment with antibiotics. Computed tomography showed a heterogeneous mass in the pleural cavity compressing the lung tissue, in addition to bilateral mild pleural effusion. Thoracotomy was indicated and the tumor was completely resected.

Clinical discussion

Histopathological and Immunohistochemical approach is crucial because this type of tumor can overlap with many soft tissue sarcomas. After searching in medical literature, no published evidence of a similar case was found, and thus we managed the patient empirically, depending on the usual approach for congenital fibrosarcoma. Complete surgical resection is the golden standard of treatment, followed by chemotherapy depending on pathological findings.

Conclusion

Clinical awareness is important in any unresponsive pneumonia and malignancies should be taken into consideration.

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Congenital infantile fibrosarcoma (CIFS) is a rare tumor and is often seen after birth and evolve during the early years of life.

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CIFS can manifest in several places in the body but rarely in chest cavity.

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Immunohistochemistry is a significant assistant in the diagnosis of soft tissue neoplasms.

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Complete surgical resection is the golden standard in treatment followed by chemotherapy depending on pathological findings.

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Local recurrence is a common phenomenon and occurs in 20–40 % of cases.

Unusual Case of Concurrent Retroperitoneal Congenital Infantile Fibrosarcoma and Cellular Type Congenital Mesoblastic Nephroma

BACKGROUND

Although congenital infantile fibrosarcoma (cIFS) is a rare soft tissue sarcoma among children, it constitutes one of the most common soft tissue sarcomas during the first year of life. Congenital mesoblastic nephroma (CMN) is the most common benign renal tumor usually developing during the first 3 months of life. cIFS and cellular type CMN (cCMN) share not only similar histopathologic features but identical molecular genetic abnormality including the ETV6/NTRK3 fusion gene. Here, we report an unusual case of cIFS occurring with cCMN.

CASE PRESENTATION

An 18-month-old girl presented with a 1-month history of abdominal distension and a few days' history of a palpable abdominal mass. A large heterogenous mass sized 9.0×11.2×11.6 cm on the right side of the abdomen and an isolated heterogenous lesion sized 4×4.5 cm within the right kidney were noted from the imaging study. Pathologic findings were consistent with cIFS and cCMN of the right kidney. In addition, both pathologic specimens contained the ETV6/NTRK3 fusion gene.

CONCLUSION

Although cIFS and cCMN share similar histopathologic features and molecular genetic abnormality, simultaneous occurrence of these 2 types of tumor is exceedingly rare. To our knowledge, this is the first unusual case report of concurrent cIFS and cCMN.

Recurrent and metastatic congenital mesoblastic nephroma: where does the evidence stand?

PURPOSE

Fifty years ago, Bolande described Congenital Mesoblastic Nephroma (CMN) as a benign lesion. Unexpected aggressive clinical behaviors prompted a sub-classification based on histology. Recent molecular genetic evidence has identified the aggressive cellular variant to be the renal manifestation of congenital infantile fibrosarcoma. We submit a reappraisal and analysis of the available literature on recurrent and metastatic CMN.

METHODS

An electronic search of PubMed, MEDLINE, EMBASE, and Scopus yielded 38 children with local recurrence and/or metastases.

RESULTS

Of the 38 children with local recurrence and/or metastasis, 59% were girls. Median time to recurrence was 6 months (range 1-12 months). The commonest sites of metastases were the lung (39%) and liver (29%). Fifty percent of these children died of disease. The outcome of additional chemotherapy (p = 0.5) did not differ from that of surgery alone. The choice of chemotherapy did not influence the outcome (p = 0.6).

CONCLUSIONS

Recurrence and metastasis in cellular CMN are much more common than described earlier and carry a high mortality. Children with cellular and mixed CMN require close clinical and radiological follow-up for a minimum of 12 months after primary surgery. Surgery is the mainstay of the treatment of recurrent and metastatic lesions. Neoadjuvant chemotherapy is recommended only if the lesion is inoperable. Targeted therapy may be an option in treatment of refractory cases.

Extracalvarial Composite Infantile Myofibromatosis: Case Report and Literature Review

Infantile soft tissue tumors of the head are very rare and the majority of them are myofibromas. The authors present the case of a 1-day-old boy with a scalp tumor with several distinct histopathological features including myofibroma, hemangiopericytoma, and fibrosarcoma consistent with the diagnosis of composite infantile myofibromatosis. Genetic testing was negative for trisomy 17, translocation (12; 15), FUS, and ETV6 translocations. Despite the ominous histopathological features, the clinical course was benign. The authors review here available literature concerning current concepts of making the diagnosis of composite infantile myofibromatosis and discuss treatment options.

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.

Congenital infantile fibrosarcoma of the colon: a case series and literature review

Congenital infantile fibrosarcoma is rare and only three cases affecting the colon have previously been reported. We describe two further cases that presented in the neonatal period and were both successfully treated with surgical excision and have no evidence of recurrence or metastasis at 31 and 27 months follow-up, respectively.

Congenital mesoblastic nephroma: Clinical analysis of eight cases and a review of the literature

Congenital mesoblastic nephroma (CMN) is a mesenchymal renal tumor. The aim of the present study was to review the clinical characteristics and outcome of CMN in infants. A retrospective file review was conducted of eight cases of CMN treated at the Children’s Hospital of Fudan University between 2004 and 2012. Ultrasound and computerized tomography scans had been performed on all eight patients. Two cases presented with a solid tumor and exhibited pathological features consistent with those of classic CMN, five cases exhibited cystic, hemorrhagic and necrotic characteristics, with calcification and pathology consistent with the cellular variant of CMN and one case presented with a solid tumor, which exhibited pathological features consistent with ceullular CMN. Histology confirmed classic CMN in two patients and cellular CMN in six patients. For surgical intervention, four cases had radical nephrectomy, one case had a half nephrectomy and three cases had tumor enucleation performed. Two cases had received pre-operative chemotherapy, but exhibited no response, and three cases received post-operative chemotherapy. Two patients were lost to follow-up, but the remaining six patients survived to the end of follow-up without further complications. The mean follow-up time was 24.6 months. In conclusion, the differential diagnosis between CMN and Wilms’ tumor is critical. Imaging characteristics are partially correlated with pathological characteristics. Surgery is the main treatment for CMN, but pre-operative chemotherapy is not particularly effective. The efficacy of post-operative chemotherapy requires further investigation, but the prognosis is positive.

Margin status and multimodal therapy in infantile fibrosarcoma

PURPOSE

The rarity of infantile fibrosarcoma (IF) has precluded comprehensive treatment evaluation. The purpose of this study was to better define the extent of surgical resection required and the role of chemotherapy.

METHODS

Patients (0-2 years) with IF were evaluated from the National Cancer Data Base (1985-2007). Survival was estimated using the Kaplan-Meier method stratifying patients by margin status and treatment with or without chemotherapy.

RESULTS

Of the 224 patients, 171 (76.3 %) were <1 year of age. Of the 64 (28.6 %) with positive margins, 36 (56.3 %) had microscopic disease, 12 (18.8 %) had macroscopic disease, and 16 (25 %) had unknown margin status; none were found to have metastases. Most were managed with surgical resection (171, 76.4 %). The proportion treated with both surgery and chemotherapy increased over time (18-40 %, p = 0.025). Disease-free survival was 90.6 %. No significant survival difference was noted in this retrospective, non-randomized cohort based on margin status, nodal involvement, tumor size, or treatment modality.

CONCLUSIONS

The use of multimodal therapy has increased over time. There was a small increase in survival associated with negative margins and the use of multimodal therapy, however, neither result reached significance. Future studies investigating tumor biology and chemosensitivity will likely determine the optimal management of IF.

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.

[Fibrosarcoma in children and adolescents: different entities for the same name]

Fibrosarcomas (FS) are rare malignant tumors in pediatrics, classified in the heterogeneous non-rhabdomyosarcomas group of malignant mesenchymal tumors. Infantile FS are found typically in children less than 2 years of age, and include congenital FS usually occurring in infants in the first 3 months of life. Histological diagnosis can be difficult; and confirmed with detection by molecular biology of the ETV6-NTRK3 fusion protein. FS is most often a localized disease at diagnosis, with involvement of an extremity. The management of these patients must be multidisciplinary, to define the different phases of treatment and avoid mutilating surgery. Cellular or atypical mesoblastic nephroma (MN) is a subtype of malignant pediatric renal tumors, most often present in children of less than 3 months. Histopathological characteristics of the cellular MN are very close to the congenital FS due to a fusion transcript common to both diseases. Treatment schedule is defined by initial local stage of the disease. FS called "adult-type" found exceptionally in childhood occur most often after 10 years old. Adult FS differ from infantile FS in their clinical presentation because of a strong local aggressiveness and problematic appearance of metastasis in 50% of cases, sometimes late. These three diseases present therefore histological similarities. Both have a common name but different clinical presentation and outcome: infantile FS and adult FS. Two have different names and initial location but similar histology, chromosomal rearrangement, sensitivity to chemotherapy and outcome: the congenital FS and cellular mesoblatic nephroma. Authors present a review of the literature of these entities.

Prenatal management of congenital infantile fibrosarcoma: unexpected outcome

We report the case of a large leg tumor in a fetus at 36 weeks of gestation. The tumor's location, ultrasound characteristics and magnetic resonance imaging (MRI) findings enabled a prenatal diagnosis of congenital fibrosarcoma and allowed us to establish the prognosis. After multidisciplinary discussion, it was decided that the pregnancy should continue to 38 weeks, with surgery or neo-adjuvant chemotherapy scheduled after delivery. Unfortunately, the tumor unexpectedly burst in utero and the newborn died of the consequences of hemorrhagic shock, despite rapid amputation. Histological examination confirmed the nature of the tumor. The prognosis of congenital fibrosarcoma is generally good when there are no metastases. MRI is key to establishing a prenatal diagnosis. However, rupture of the tumor can result in fatal hemorrhaging and the pregnancy should be monitored closely before scheduled delivery.

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.

Regression of a congenital mesoblastic nephroma

Histologically, the cellular variant of congenital mesoblastic nephroma (CMN) is very similar to another rare tumor of infancy, infantile fibrosarcoma (IFS). In addition to the histologic similarities, these tumor types share cytogenetic abnormalities including translocation t(12;15)(p13;q25). We describe herein the case of a child who did not have immediate surgical resection of a CMN and whose tumor was untreated for 8 months. During that time, the tumor demonstrated a significant degree of regression. The shared translocation with IFS, a tumor with well-documented potential for spontaneous regression, suggests that this genetic abnormality may have contributed to the favorable clinical course.

Right foot congenital infantile fibrosarcoma treated only with chemotherapy

Congenital infantile fibrosarcoma (CIF) is a rare tumor in childhood. The 5-year survival rate for CIFs is high and has been reported between 84% and 93%, but limb-amputation/disarticulation is still a major problem. We report the case of a male newborn with a mass in his right foot. X-ray and MRI revealed a mass destroying all tarsal, metatarsal, and phalangeal bones. The patient was treated only with VAC chemotherapy and is able to walk normally.

Infantile fibrosarcoma: management based on the European experience

PURPOSE

To retrospectively analyze the clinical features and results of treatment in 56 infants with fibrosarcoma enrolled onto cooperative European protocols between 1979 and 2005 and treated with a combination of surgery and chemotherapy.

PATIENTS AND METHODS

We performed a retrospective case review of infants under the age of 2 years with fibrosarcoma treated between 1979 and 2005 in six European studies. Patients were staged according to the Intergroup Rhabdomyosarcoma Staging System international classification as a function of the type of initial surgery and the extent of disease and were treated with surgery and chemotherapy. Survival was calculated using the Kaplan-Meier method.

RESULTS

Primary tumor site was the limbs in 66% of patients; median tumor diameter was more than 5 cm in 63% of patients; and postoperative staging was as follows: group I, 22%; group II, 27%; group III, 47%; and group IV, 4%. Response rate to chemotherapy was 75%, and the specific response rate to vincristine-dactinomycin was 71%. Local control was obtained in 84% of patients. At the end of follow-up, 45% of survivors had been treated by surgery alone, 6% by chemotherapy alone, 46% by surgery and chemotherapy, and 2% by surgery, chemotherapy, and radiotherapy. The 5-year overall survival (OS) rate was 89%. The 5-year OS and event-free survival rates for localized patients were 89% and 81%, respectively.

CONCLUSION

Although complete resection is rarely feasible at diagnosis, conservative surgery remains the mainstay treatment for infantile fibrosarcoma. An alkylating agent-free and anthracycline-free regimen is usually effective and should be chosen as first-line chemotherapy for inoperable tumors. Overall prognosis is good, but progression or relapse, mainly local, remains possible.

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.

[Soft tissue tumors in neonates]

Soft tissue tumors account for approximately 25% of neonatal tumors and are most often benign (more than 2/3 of cases). Vascular tumors are the most frequent benign tumors and infantile hemangioma accounts for 32% of these tumors, affecting 1 out of 200 children at birth. Kaposiform hemangioendothelioma (KH) is a rare vascular tumor with locally aggressive behavior. More than 50% of KH are associated with the Kasabach-Merritt phenomenon, a condition characterized by thrombocytopenia and consumptive coagulopathy. Malignant soft tissue tumors are, after neuroblastoma, the second cause of cancer in neonates. Infantile fibrosarcoma (IF) is a rare tumor that most often affects the extremities of children aged 4 years or younger. A recurrent t(12;15) (p13;q25) rearrangement fusing the ETV6 gene with the NTRK3 neurotrophin-3 receptor gene has been identified in IF. Complete conservative surgical resection is usually curative. Chemotherapy is indicated when initial surgical removal cannot be accomplished without unacceptable morbidity. Prognosis of IF is excellent, with reported overall survival rates ranging from 80 to 100%. Neonatal rhabdomyosarcoma (RMS) is a rare tumor (0.5-1% of RMS). The primary tumor predominantly involves the limbs and the genitourinary tract. Treatment is based on age-adapted chemotherapy and surgery. Prognosis of RMS in children less than 1 year old appears to be comparable with that of older children.

Fetal and placental malignancies: prenatal diagnosis and management

Fetal and placental malignancies are rare complications during pregnancy, but when they occur they may present significant challenges for the perinatology team. Owing to their rarity, there is limited information on many of these entities, with much data derived from individual case reports or small case series. Prenatal diagnosis of these entities is rare and inconsistent, usually in the form of isolated case reports. In the majority of fetal tumors, prenatal features are those of a mass lesion, with or without other non-specific features of fetal compromise such as polyhydramnios, fetal hydrops or intrauterine death, the final diagnosis in most cases being based on postnatal pathological examination.Expectant management is almost always indicated antenatally, with serial ultrasound examinations performed to detect rapid enlargement, metastasis or secondary fetal complications, such as non-immune hydrops, which may require intervention. Delivery should be planned in a specialist center in conjunction with pediatric surgeons and oncologists to allow appropriate neonatal management. Placental malignancy is most commonly in the form of gestatational trophoblastic disease, which requires assessment and management in specialist centers.

Secretory breast carcinomas with ETV6-NTRK3 fusion gene belong to the basal-like carcinoma spectrum

Secretory breast carcinomas (<0.15% of breast tumors) are associated with a characteristic morphology and a favorable prognosis. Remarkably, this entity is the only epithelial tumor of the breast with a balanced translocation, t(12;15), that creates an ETV6-NTRK3 gene fusion encoding chimeric tyrosine kinase also encountered in cellular mesoblastic nephroma and infantile fibrosarcoma. The aim of this study was to determine the phenotypic class (ie luminal A/B, ERBB2, basal-like) of secretory breast carcinoma. A series of six secretory breast carcinomas were identified in our files. The ETV6 rearrangement was confirmed in all cases by fluorescence in situ hybridization. Immunophenotype was assessed with anti-ER, PR, ERBB2, KIT, EGFR, E-cadherin, vimentin, PS100, smooth muscle actin, basal (CK5/6 and 14), luminal cytokeratins (CK8/18) and p63 antibodies. In situ and invasive components shared the same immunoprofile and were ER, PR, ERBB2 negative with expression of basal cytokeratins. ETV6 gene alterations were present in both in situ and invasive components, highlighting their genetic similarities. The immunoprofile data (triple-negative with expression of basal markers) showed that secretory breast carcinomas with ETV6-NTRK3 fusion gene belong to the phenotypic basal-like spectrum of breast carcinomas. These results support the hypothesis that secretory breast carcinomas have immunohistochemical and genetic features that distinguish them from other basal-like tumors of the breast.

Congenital/Infantile fibrosarcoma of the colon: morphologic, immunohistochemical, molecular, and ultrastructural features of a relatively rare tumor in an extraordinary localization

Fibrosarcomas diagnosed during the early years of life are called congenital/infantile fibrosarcomas. They differ from adult fibrosarcomas because of their limited aggressive outcome. Congenital/infantile fibrosarcomas occur most frequently on the extremities. This article describes an exceptional case of colonic congenital/infantile fibrosarcoma diagnosed in a 3-day-old baby boy. It is the third intestinal congenital/infantile fibrosarcoma reported in the international literature. The lesion was radically excised. Microscopic examination revealed a densely cellular and poorly circumscribed tumor composed of spindle cells forming interlacing fascicles with herringbone appearance. Necrotic and hemorrhagic areas were appreciable. Mitotic count was 2/10 high-power fields. Immunohistochemistry revealed that the tumor cells were positive for vimentin, focally positive for h-caldesmon, and that they were negative for epithelial markers, muscular markers, S-100 protein, and CD34. The proliferation index (Mib-1) was 15%. Polymerase chain reaction demonstrated the chromosomal translocation t(12;15) (p13;q25). At the ultrastructural level, neoplastic cells had fibroblastic and myofibroblastic features. The patient underwent follow-up without adjuvant therapy. Twelve months after the surgery, he is alive and well. Given the common indolent nature of this tumor, it is important to avoid misdiagnoses with more aggressive tumors. The algorithm for the diagnosis of congenital/infantile fibrosarcoma, especially outside the usual localizations, should comprise morphologic, immunohistochemical, molecular, and ultrastructural studies.

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.

Part II: Treatment of primary malignant non-Wilms' renal tumours in children

Renal-cell carcinoma, clear-cell sarcoma, (congenital) mesoblastic nephroma, rhabdoid tumour, and renal medullary carcinoma form a heterogeneous group of childhood renal malignancies known as non-Wilms' tumours. Progress has been slow in improving the management of these tumours to decrease morbidity and increase survival. However, greater cooperation between national and international centres should engender specialisation, and an increased knowledge of the molecular biology of these tumours will inevitably lead to substantial progress over the next decade. This review is the second of two parts: the first part provided an updated review of the clinical presentation, imaging, and pathology of non-Wilms' tumours and this second part provides an updated review of the treatment of these tumours.

Atypical congenital mesoblastic nephroma presenting in the perinatal period

Congenital mesoblastic nephroma (CMN) is a rare tumour of infancy having an overall good prognosis. The less common, atypical CMNs have cellular elements in them and tend to have an unpredictable course. Occurrence in the perinatal period may further change the outcome. By reporting three patients presenting in the perinatal period with atypical CMN, an attempt is made in this paper to characterize the clinical behaviour of these variant tumours. Though one of our patients had an uneventful course, the other two had several complications including polyhydramnios, prematurity, hypertension, haemodynamic instability and tumour spillage. The course was complicated by recurrence in the latter two and refractoriness to chemotherapy and death in one. That the atypical subset of CMNs occurring in the perinatal period can have a stormy course is well illustrated by this report. Possible prognostic factors are evaluated and the sparse reports of similar cases in the literature are reviewed and compared.

Congenital infantile fibrosarcoma: a masquerader of ulcerated hemangioma

Congenital infantile fibrosarcoma, a rare malignant tumor of childhood, may present as a highly vascularized mass that is clinically difficult to distinguish from a hemangioma. When ulcerated, significant hemorrhage, anemia, and thrombocytopenia may occur in children with these lesions. This report describes three infants with ulcerated congenital infantile fibrosarcomas of the hand. As appropriate medical and surgical management hinges on timely and appropriate diagnosis, we review the clinical manifestations of these lesions.

Mesoblastic nephroma—A report from the Gesellschaft fur Pädiatrische Onkologie und Hämatologie (GPOH)

BACKGROUND

Surgery alone is the appropriate first-line treatment for patients with mesoblastic nephroma (MN). Nevertheless, there are reports of local recurrences and metastasis, especially in the cellular subtype. The authors evaluated the outcome of patients with MN who were enrolled in either the International Society of Pediatric Oncology (SIOP) 93-01/GPOH or the SIOP 2001/GPOH Nephroblastoma Study and Trial.

METHODS

In total, 50 patients with MN were analyzed. Eleven patients were suspected antenatally of having a renal tumor. The median age at diagnosis was 18.5 days. Central pathologic review was performed for all specimens. The median observation time was 4.2 years.

RESULTS

Forty-five patients underwent initial surgery. Five patients older than 6 months received preoperative chemotherapy. Twenty-nine tumors were classic MN, and 21 tumors were cellular MN. Nine patients had a Stage III MN, 5 of those patients had tumor ruptures, and 8 had positive surgical margins. After they underwent nephrectomy, 40 patients received no further treatment. For the entire group, event-free survival (EFS) (94%) and overall survival (OS) (95%) were excellent. Patients with a cellular MN, patients with age 3 months or older, and patients with Stage III MN had lower EFS. Three patients developed recurrent disease, and 2 of those patients died. Metastases to the brain, lung, and liver were observed in 1 patient.

CONCLUSIONS

Radical nephrectomy with accurate surgical-pathologic staging is the standard of care for children with MN. Nonetheless, a subgroup of patients with MN (Stage III cellular MN in patients age 3 months or older) tends to develop recurrences more often. Further prospective studies will be needed to verify this finding and should help determine whether these patients may benefit from adjuvant therapy.

Secretory carcinoma of the breast containing the ETV6-NTRK3 fusion gene in a male: case report and review of the literature

SUMMARY

BACKGROUND

Secretory carcinoma (SC) of the breast is a rare and indolent tumor. Although originally described in children, it is now known to occur in adults of both sexes. Recently, the tumor was associated with the ETV6-NTRK3 gene translocation.

CASE PRESENTATION

A 52-year-old male was diagnosed with secretory breast carcinoma and underwent a modified radical mastectomy. At 18 months the tumor recurred at the chest wall and the patient developed lung metastases. He was treated concurrently with radiation and chemotherapy without response. His tumor showed the ETV6-NTRK3 translocation as demonstrated by fluorescent in situ hybridization (FISH).

CONCLUSION

SC is a rare slow-growing tumor best treated surgically. There are insufficient data to support the use of adjuvant radiation or chemotherapy. Its association with the ETV6-NTRK3 fusion gene gives some clues for the better understanding of this neoplasm and eventually, the development of specific therapies.

Pediatric malignancies provide unique cancer therapy targets

PURPOSE OF REVIEW

Improving overall survival and reducing morbidity are major goals of childhood cancer research. This review explores an old idea that increased survival in childhood cancer can be achieved by inhibiting specific cancer targets. Specific therapeutic targeting would theoretically cause reduced morbidity as well as increased survival. Tumor-specific translocation-generated fusion proteins appear to be ideal tumor-specific therapeutic targets. This review will describe advances in aspects of target identification, potential for small molecule screening, and the evolution of clinical resistance to this new generation of pharmaceuticals.

RECENT FINDINGS

Advances in molecular biology have identified new protein targets along with increased understanding of the biologic role of these proteins. Ewing sarcoma family of tumors research has benefited from new target discovery and enhanced biologic understanding of the EWS-FLI1 fusion protein. Congenital (infantile) fibrosarcoma and cellular mesoblastic nephroma have been grouped based on the presence of a common translocation fusion protein, ETV6-NTRK3. Functional knowledge of ETV6-NTRK3 has advanced so that strategies for screening small molecule inhibitors can proceed. Patients with chronic myeloid leukemia have benefited from the discovery of the BCR-ABL kinase inhibitor imatinib mesylate (Gleevec), thus showing how a molecular therapeutic target can be inactivated for improved therapy. This review will describe challenges raised by clinical resistance to imatinib mesylate as a paradigm for how resistance might evolve in other disease models. This review also describes how patients with synovial sarcoma might benefit from future therapy directed towards the SYT-SSX family of fusion proteins.

SUMMARY

The increased utilization of small molecules to disrupt or inactivate tumor-specific molecular targets is rapidly evolving. The use of these small molecules to probe biology and treat disease is advancing towards a new generation of anticancer therapies.

Treatment effects in pediatric soft tissue and bone tumors: practical considerations for the pathologist

Dramatic improvements in survival for children with cancer have led to increased numbers of posttreatment pathologic specimens, particularly in bone and soft tissue sarcomas. Current therapeutic protocols in North America require specific pathologic classification and stratify patients based on clinical, biologic, and pathologic features. For osteosarcoma, the pathologic response to therapy predicts prognosis and modifies the treatment regimen. Ongoing studies aim to assess the response to therapy and outcome in other types of soft tissue and bone tumors. The pathologic evaluation of pretreatment and posttreatment specimens is critical for therapeutic decisions and prognostic assessment. A standardized approach to posttherapy pathologic specimens, with attention to appropriate use of ancillary tests, and assessment of clinical and biologic significance of therapy-induced pathologic changes has significance for patient management and treatment protocols.

Gene expression profiling of mesoblastic nephroma and Wilms tumors—comparison and clinical implications

OBJECTIVES

To better understand the molecular mechanisms in the tumorigenesis and progression of mesoblastic nephroma (MN), we studied its gene expression profiles. MN is the most common tumor of the neonatal kidney. It occurs in a younger age group than the Wilms tumor (WT). To date, very little is known about the etiology and pathogenesis of MN.

METHODS

Using microarrays containing 22,943 cDNA, we analyzed the expression profiles of MN and compared its expression profiles with those of several other types of kidney tumors, including WT.

RESULTS

MN has a distinct molecular signature that clusters close to the WT, suggesting that both types of tumor share some similarity in gene expression and biology. When comparing the two profiles closely, we identified a number of genes that are commonly upregulated in both tumors, including insulin-like growth factor 2, thrombospondin 4, and mesenchyme homeo box 1. We also identified a set of genes that distinguish MN from WT, some of which may underlie the difference in their behaviors and can be used as diagnostic markers. Among this group of genes, topoisomerase II-alpha, highly expressed in WTs, is not overexpressed in MN. Immunohistochemical staining of topoisomerase II-alpha in additional cases of WTs and MNs confirmed this distinction further.

CONCLUSIONS

The results of our study demonstrated that MN has a distinct gene expression profile and that some of the newly identified genes can be potentially used as novel diagnostic markers.