Forty-week-old newborn, male sex, controlled pregnancy, eutocic delivery, with no perinatal morbid history.
Erythematous erythematous plaque caused by a mild plaque located in the peri- and infraumbilical region present since birth, with well-defined local signs and desquamation superficial adherents in the inflammatory pole.
A skin ultrasound revealed a homogeneous hypoechogenic dermoepidermal lesion, with mild extension to subcutaneous tissue and few sinuous vessels in its deepest segment.
Given the clinical characteristics, a deep incisional biopsy was performed, which showed proliferation of thin spindle cells in dermis and hypodermis, of biphasic morphology with an absence of myofibroblastic band pattern and fusiform segment.
In-depth examination revealed a component of mature adipose tissue, with no signs of atypia.
Epidermis mature, partially atrophic.
Necrosis and mytosis were not observed.
Immunohistochemical study of tumor cells showed intense and diffuse positivity for CD34 and focal for FXIIIa, with absence of actin, desmin, HMBA E451, S100 immunoreactivity.
Proliferation index with moderate Ki67, with positivity in approximately 20% of cells.
A study was completed with FISH for PDGF beta and ETV6, which resulted negative, excluding differential diagnoses of dermatofobrosarcoma probands congenital fibrosarcoma and fibrosarcoma infantile recurrently.
These antecedents, together with the histological findings, were compatible with the diagnosis of HFI.
A surgical excision was performed by a pediatric surgery unit with umbilical readjustment using lateral rotation flaps.
Histological and immunohistochemical studies compromise margins of surgical resection.
The patient remained asymptomatic after 7 months of follow-up.
