congenital myofibroma
TRANSCRIPT
Congenital myofibroma.A true hemangiopericytoma.
A neonatal case with immunohistochemical and
ultrastructural studies.Ezequiel Trejo-Scorza
Alipio Antonio Hernández-Faraco Jesùs Marìa Alvarado-Sanavria
Maternidad “Concepciòn Palacios”República de Venezuela
Introduction Malignant tumors in the newborn are rare. Mejia-
Aranguré (1) found only 74 cases in a series of 4595 cases. (2005)
In newborns, the most common solid tumors are: Neuroblastoma Teratomas Soft tissue tumors
The most common soft tissue tumors are: Myofibroma / myofibromatosis Fibrosarcoma Rhabdomyosarcomas
The most common fibroblasts and myofibroblasts tumors are: Myofibroma / myofibromatosis (benign) Fibrosarcoma (malignant)
Myofibroma single or multiple Single or multiple lesions Stout and Murray (1942): endothelium-lined ducts
surrounded by packets of round cells that show a tendency to differentiate into myofibroblasts, which called hemangiopericytoma, and derived from pericytes.
Case report RN born male, with
appropriate weight for gestational age, obtained by vaginal delivery in primiparous mother of 19 year-old.
Physical examination evidence, oval tumor 3 x 2 x 2 cm in right malar region, with a pedicle of 0.5 cm midway between the two extremes.
The surface of the pedicle contralateral tumor present area of purple, the next day becomes necrotic.
The rest of the surface was pink, well vascularized.
Diagnostic tests A CT scan revealed a tumor
of dermal origin, with the deeper layers and bone, free of infiltration.
Doppler sonogram shows low vascularity of tumor, except at the pedicle where blood flow was found.
Surgery performed
At the 4 th day of life, total excision of the lesion. Buttonhole incision around the tumor pedicle to the outer face of the right zygomatic bone.
The patient was discharged at 10º days of life with successful postoperative outcome.
Histopathology The conventional histological
examination showed tumor located in the dermis with solid nodules, isolated and confluent, expansive edge compared to normal tissue surrounding country.
It showed foci of intratumoral necrosis
Histopathology And endovascular
subendothelial growth of the tumor into dilated venules and lymphatic vessels of the dermis.
The neoplasm is characterized by a nodular proliferation with a biphasic pattern composed of round cells and spindle
Round cells were located in the central region of the lymph vascular small slits arranged between collapsed and covered with normal endothelium.(A)
The spindle cells were located in the periphery and had a look smooth muscle with blunt-ended elongated nuclei and fibrillary eosinophilic cytoplasm aspect. (B)
All tumor cells (spindle or round) exhibited strong reaction to PAS pericellular.
Immunohistochemistry Table No. 1
Results of immunoreaction Immunoreactions Results (neoplastic cells)
CD34 and vimentin Diffuse cytoplasmic positivity for spindle cell component, and for least differentiated tumor cells
Alpha smooth muscle actin Cytoplasmic positivity for spindle cell component, and less differentiated tumor cells isolated
PGP 9.5 and S100 protein Nuclear positivity for malignant cells isolated
Desmin, Factor VIII and Epstein-Barr Negative for tumor
Immunoreactions Tumor diffuse
immunopositivity for CD34. In (A) the immune response of endothelial cells to CD34 shows subendothelial tumor growth.
In (B) focal immunopositivity in peripheral spindle cells for smooth muscle actin.
Ultrastructural study Basement membrane lining
(*) Numerous cytoplasmic
intermediate filaments with dense body formation (smooth muscle differentiation) (O)
Discussion
Discussion The myofibroma is a tumor arising from pericytes and
its cells undergoing myofibroblastic differentiation Myofibroma presented the clinical, histopathological
and prognostic allowing differentiate solitary fibrous tumor and hemangiopericytoma injuries, findings reveal "hemangiopericytoma-like"
Clinic In childhood is the most common fibromatosis 90% of cases are diagnosed by 1 year of age Predilection for males It can occur alone (myofibroma) or multiple
(myofibromatosis) Single lesions are confined to the skin, subcutaneous
tissue or skeletal muscle of the head, neck or trunk When surface have the appearance of purplish spots and
doppler ecosonography allows to differentiate hemangiomas
When lesions are multiple runs with 25% damage and visceral organs most commonly affected are heart, lung and gastrointestinal tract.
Clinical prognosis
The clinical outcome will depend on the location of the tumor and the number of organs involved: Solitary visceral myofibroma Myofibromatosis with single
visceral involvement Myofibromatosis with
multiple visceral involvement
Differential Diagnosis With lesions deployed
findings "hemangiopericytoma-like“ Congenital fibrosarcoma, Solitary fibrous tumor.
Conclusion The myofibroma is a tumor that may be present at birth When the lesions are superficial and have the appearance of
purplish spots ecosonography doppler allows to differentiate hemangiomas
The immunohistochemistry and electron microscopy show clear evidence of myofibroblastic differentiation of the periendoteliales tumor cells and therefore are hemangiopericytomas true, because we propose the term “myofibropericitoma", to emphasize its pericitic origin and myofibroblastic differentiation.
True hemangiopericytomas Sinonasal-type
hemangiopericytoma with myoid differentiation
Myofibromas (myofibropericytoma)
Glomangiopericytoma Myopericytoma