Infantile myofibromatosis with visceral involvement and complete spontaneous regression

Generalized Infantile Myofibromatosis with Extensive Small Bowel Involvement in a Neonate

Infantile myofibromatosis is a rare benign congenital tumour that often regresses spontaneously but may pose therapeutic challenges in its widespread visceral form. We present the case of a full-term neonate with generalized infantile myofibromatosis including ubiquitous subcutaneous and muscular nodules, a tumour in the mastoid and disseminated intestinal involvement. The intestinal tumours led to a mechanical ileus with intestinal perforation within the first days of life. After partial small bowel resection and necessary proximal jejunostomy the boy was dependent on total parenteral nutrition. Chemotherapy with vinblastine and methotrexate was started and was temporarily supplemented with imatinib. Feeding stayed impossible despite tumour shrinkage. At the age of 4.5 months, restoration of intestinal continuity with further stricturoplasties was performed which - for the first time - allowed complete oral feeding. Chemotherapy was continued for further two months. Currently, the child is in good general condition with growth and further disease regression. This report suggests that massive visceral involvement of infantile myofibromatosis may require extensive intestinal surgery, as conservative therapy cannot resolve the disease and its sequelae.

Generalized infantile myofibromatosis with visceral involvement presenting as diffuse hypopigmented macules at birth

The initial clinical presentation of infantile myofibromatosis can vary from subtle skin changes to large tumors. Here, we describe a case of congenital generalized infantile myofibromatosis which presented with diffuse hypopigmented macules, some with subtle atrophy and telangiectasia. Further workup revealed visceral involvement which led to treatment with systemic chemotherapy. Awareness of this rare clinical presentation is crucial to expedite workup and treatment given the poor prognosis in infants with visceral involvement.

Notch Signaling in Vascular Smooth Muscle Cells

The Notch signaling pathway is a highly conserved pathway involved in cell fate determination in embryonic development and also functions in the regulation of physiological processes in several systems. It plays an especially important role in vascular development and physiology by influencing angiogenesis, vessel patterning, arterial/venous specification, and vascular smooth muscle biology. Aberrant or dysregulated Notch signaling is the cause of or a contributing factor to many vascular disorders, including inherited vascular diseases, such as cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, associated with degeneration of the smooth muscle layer in cerebral arteries. Like most signaling pathways, the Notch signaling axis is influenced by complex interactions with mediators of other signaling pathways. This complexity is also compounded by different members of the Notch family having both overlapping and unique functions. Thus, it is vital to fully understand the roles and interactions of each Notch family member in order to effectively and specifically target their exact contributions to vascular disease. In this chapter, we will review the Notch signaling pathway in vascular smooth muscle cells as it relates to vascular development and human disease.

Risk-adapted therapy for infantile myofibromatosis in children

BACKGROUND

Infantile myofibromatosis is characterized by proliferation of benign fibrous tumors arising in skin, subcutaneous tissue, muscle, or bone. Solitary and multicentric forms are described. Few reports are available in the pediatric population.

PROCEDURE

To improve the knowledge of this rare tumor in infants, the authors present a series of all cases of infantile myofibromatosis treated in their institution over a 9-year period in order to propose treatment guidelines based on their experience and a review of the literature.

RESULTS

The authors report a series of 9 cases, 8 solitary forms and 1 multicentric form with visceral involvement treated from 2000 to 2009. Median age was 10 months (range: 2 days-14 years). Six patients with solitary forms underwent primary surgical resection leading to remission. Only biopsy was performed in 1 case, followed by tumor regression with no recurrence. The last patient with a solitary form was treated by chemotherapy and then surgery allowing remission. The patient with a multicentric form presented complete regression of tumors after 1 year of vinblastine and methotrexate combination chemotherapy.

CONCLUSIONS

Infantile myofibromatosis is a rare soft tissue tumor mainly concerning infants. Surgery is the treatment of choice for solitary forms when excision is possible. Close follow-up may be proposed in the case of inoperable sites. In multicentric life-threatening forms, chemotherapy promotes tumor regression and the vinblastine and methotrexate combination is effective with few long-term adverse effects.

[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.

Colorectal infantile myofibromatosis: an unusual cause of rectal prolapse and sigmoid colo-colonic intussusception: a case report

Background

Infantile myofibromatosis is a rare mesenchymal disorder of infancy that can extensively involve the viscera including the gastrointestinal tract.

Case presentation

In this report, an exceptional case of infantile myofibromatosis is described in which rectal prolapse and sigmoid colo-colonic intussusception were the initial presentations of colorectal involvement in a 2-month-old premature female infant.

Conclusion

To the best of our knowledge, this is the first case reporting rectal prolapse and the second case documenting intussusception secondary to gastrointestinal involvement by infantile myofibromatosis.

Remission of infantile generalized myofibromatosis after interferon alpha therapy

Infantile myofibromatosis is the most common fibrous tumor of infancy. Solitary or generalized myofibromas without visceral involvement usually regress within a few months. The multifocal disease infantile generalized myofibromatosis, with visceral involvement, is associated with a significant mortality due to the effect of tumors on vital organs. We report a case of infantile generalized myofibromatosis with visceral involvement, including 2 right atrium tumors. The infant expressed high circulating vascular endothelial growth factor and fibroblast growth factor-2 levels, and interferon alpha-2b was started as antiangiogenic treatment, aimed at triggering regression of the life-threatening cardiac lesions. The tumors regressed and vascular endothelial growth factor and fibroblast growth factor-2 levels were reduced after treatment discontinuation.

Successful treatment of relapsed multifocal nonvisceral infantile myofibromatosis

Infantile myofibromatosis is a very rare tumor in childhood and infancy. The authors report on a 4-year-old boy who presented with two relapses of initially multifocal infantile myofibromatosis without visceral involvement. The lesions of the skull and the abdomen were excised while osteolytic lesions of the limbs were not treated. Chemotherapy or radiation have not been applicated. Three years after initial diagnosis there is no evidence for persistence or recurrence of the tumor.

Infantile myofibromatosis: a most unusual cause of gastric outlet obstruction

Non-bilious vomiting in the newborn is common. Etiologies include both surgical and medical conditions. Gastroesophageal reflux, soy or milk protein allergy, and prostaglandin-induced foveolar hyperplasia are among the medical causes. Surgical entities include gastric antral webs, pre-ampullary duodenal and pyloric atresia, and hypertrophic pyloric stenosis. We report the unique case of an 8-day-old girl who presented with gastric outlet obstruction secondary to infantile myofibromatosis.

Fetal hemangiopericytoma with an associated cerebral anomaly

We report the first case of infantile hemangiopericytoma explored prenatally by fetal ultrasonography and magnetic resonance imaging (MRI). It was associated with a developmental cerebral anomaly identified on MRI. The largest lesions of the multifocal hemangiopericytoma were located in the soft tissue adjacent to the left temporal bone, and smaller lesions were found in the lumbar area and in the retroperitoneum. MRI showed no connection between the tumor and the fetal brain but there was anomalous cerebral gyration in the region and the Sylvian fissure beneath the tumor was enlarged. The pregnancy was terminated because of the severe brain anomalies and postmortem examination confirmed the prenatal findings. Microscopic analysis of the tumor tissue showed branching vessels which are typical of hemangiopericytoma. The lesions in our case occurred in association with macrosomia with visceromegaly detected at autopsy, suggesting a possible role of tumor suppressor genes.

Endocardial location of familial myofibromatosis revealed by cerebral embolization: cardiac counterpart of the frequent intravascular growth of the disease?

Myofibromatosis is a rare infantile benign neoplasia, which may involve the heart in the rare and usually fatal generalized form of the disease. Diagnosis of endocardial myofibromas was made on two surgically excised lesions of the mitral valve that were reveled by a cerebral embolization in a 12-month-old female infant. Surprisingly, the patient had no other obvious lesion of myofibromatosis. However, her father had a histologically proven neonatal history of myofibromatosis. This case confirms the likely autosomal dominant mode of inheritance of myofibromatosis. It highlights the embolization risk of the previously unreported endocardial location. We suggest that these clinically isolated non-invasive endocardial myofibromas did not represent a true visceral form of myofibromatosis. They were, rather, similar to the frequent intravascular growth of the disease.

Successful treatment of life-threatening generalized infantile myofibromatosis using low-dose chemotherapy

Infantile myofibromatosis is the most common fibrous tumor of infancy. The generalized form of the disease is associated with a high rate of early mortality, especially if visceral structures are involved. Various therapeutic strategies have been used in these patients, including high-dose chemotherapy, with the risk of therapy-related toxicity. The authors present two cases of generalized infantile myofibromatosis, with life-threatening visceral and nonvisceral involvement, in which the patients were cured with a combination of low-dose chemotherapy and intensive care. The authors propose a prospective international trial using a safe low-dose chemotherapy protocol to test the efficacy of this treatment strategy.