Activating variants in PDGFRB result in a spectrum of disorders responsive to imatinib monotherapy.

More than 50 individuals with activating variants in the receptor tyrosine kinase PDGFRB have been reported, separated based on clinical features into solitary myofibromas, infantile myofibromatosis, Penttinen syndrome with premature aging and osteopenia, Kosaki overgrowth syndrome, and fusiform aneurysms. Despite their descriptions as distinct clinical entities, review of previous reports demonstrates substantial phenotypic overlap. We present a case series of 12 patients with activating variants in PDGFRB and review of the literature. We describe five patients with PDGFRB activating variants whose clinical features overlap multiple diagnostic entities. Seven additional patients from a large family had variable expressivity and late-onset disease, including adult onset features and two individuals with sudden death. Three patients were treated with imatinib and had robust and rapid response, including the first two reported infants with multicentric myofibromas treated with imatinib monotherapy and one with a recurrent p.Val665Ala (Penttinen) variant. Along with previously reported individuals, our cohort suggests infants and young children had few abnormal features, while older individuals had multiple additional features, several of which appeared to worsen with advancing age. Our analysis supports a diagnostic entity of a spectrum disorders due to activating variants in PDGFRB. Differences in reported phenotypes can be dramatic and correlate with advancing age, genotype, and to mosaicism in some individuals.

Ruptured Infantile Myofibroma of the Head Presenting in a Neonate: Case Report and Review of the Literature.

BACKGROUND: Infantile myofibroma/myofibromatosis (IM/M) is a myofibroblastic proliferative disorder often seen in infants and children. IM/M can result in congenital tumors of the head and neck and may occasionally present to the neurosurgeon. CASE DESCRIPTION: We report a case of a solitary ruptured myofibroma of the head in a newborn patient. The lesion was initially suggestive of encephalocele. We describe the presentation and management of this patient, including relevant imaging, histopathologic evaluation, and surgical technique. We subsequently review the literature of IM/M of the head and neck, highlighting the 3 forms of the condition, each requiring a distinct management strategy. CONCLUSIONS: Although this tumor rarely presents to the neurosurgeon, it may do so in the process of ruling out other more dangerous conditions. It is therefore important to consider this diagnosis in masses that occur in the head and neck of newborns.

Infantile myofibroma: a case report and review of the literature.

This article presents a case report of a 37-week gestational age (GA) female infant (CK) whose first ultrasound at 35 weeks' GA revealed polyhydramnios, fetal ascites, and a possible diaphragmatic hernia. At birth, CK had a grossly distended abdomen, prominent abdominal veins, hepatomegaly, bounding femoral pulses, and generalized edema. Initial imaging identified an absent ductus venosus, absent segment of the inferior vena cava (IVC), and prominent superior vena cava to the right atrium. A computed tomography (CT) scan showed a mass contiguous with the liver causing compression of the IVC. Biopsy confirmed infantile myofibromatosis (IM), an uncommon soft tissue neoplasm that may present at birth or in early infancy. Although rare, this neoplasm is the most common fibrous tumor of infancy. The case of CK was unusual because the solitary IM lesion was in an atypical location; a solitary lesion is not commonly found in the viscera, and solitary lesions are predominant in males. Although lesions are often benign, visceral involvement is associated with high mortality. The cause is unknown, although familial cases have been reported. This article describes the key features of IM, possible treatment options, nursing care, and prognosis for infants with the disease.

Perivascular myoma of myopericytoma and myofibromatosis-type arising in a chronic scar.

We describe a case of a cutaneous perivascular myoma with features overlapping between the myofibromatosis and the myopericytoma type. The patient is a 58-year-old woman with a painless plaque-like and multinodular lesion in the pretibial dermis and subcutaneous tissue. She had repeated trauma to this site, first in her early youth that left an area of hyperpigmentation, and then again at age 40. The biopsy showed a biphasic pattern with a myofibromatosis-type component composed of spindle cell myoid nodules and more cellular round cell areas. The myopericytoma-like areas appeared to be infiltrating along vessels. These areas contained aggregates of immature-appearing cells arranged concentrically around vascular lumina in a manner reminiscent of pericytes. Immunohistochemical stains showed focal positivity for smooth muscle actin. Immunohistochemical and ultrastructural studies have showed these pericyte-like cells to be of a myoid origin. The reason for the neoplastic proliferation of perivascular myoid cells is presently unknown. The association of trauma and neoplastic transformation of the skin is rare. We report the first case of a cutaneous perivascular myoma arising in a chronic scar.

Leiomiosarcoma infantil con células gigantes de tipo osteoclástico / Infantile leiomyosarcoma with osteoclast-like giant cells

El presente artículo describe el caso de un paciente de siete años intervenido por tumoración de 3 cm en la pared abdominal. El estudio anatomopatológico demostró un leiomiosarcoma de grado bajo con células gigantes de tipo osteoclástico. La presencia de células gigantes de tipo osteoclástico en el leiomiosarcoma ha sido excepcionalmente descrita, lo que unido a la rareza de eta neoplasia en la edad infnatil puede plantear problemas de diagnóstico diferencial con otros tumores de partes blandas infantiles benignos o malignos, especialmente con la miofibromatosis infantil. La hibridación in situ no demostró que el virus de Epstein-Barr estuviera implicado en la patogénesis de este caso (AU)

Miofibromatose congênita: relato de caso / Congenital miofibromatose: case report

Os autores apresentam um caso de miofibromatose congênita, cursando com tumoração em região escapular direita e comprometimento ósseo. O diagnóstico foi sugerido por exames de imagem: radiografia do esqueleto e ressonância nuclear magnética, e confirmado pelo estudo histopatológico da lesão. Por ser uma doença rara os autores fazem uma revisão bibliográfica, descrevendo aspectos de apresentação e evolução clínica da doença, avaliação diagnóstica, e abordagem terapêutica