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| July
2008
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PATH QUIZ CASE
9 : (HISTORY AND IMAGES):
(Benign Infantile Hemangioendothelioma; Cellular Hemangioma of Infancy; Juvenile Hemangioma; Strawberry nevus.)
Image Link1 Infantile hemangiomas, the most common tumours of infancy, are vascular tumours characterized by rapid proliferation of endothelial cells during the first few months of postnatal life followed by slow spontaneous involution. Pathogenesis of hemangioma is not understood. Growth factors and hormonal and mechanical influences have been postulated to affect the abnormal proliferation of endothelial cells in hemangioma. The primary, causative defect in hemangiogenesis is not known and no genetic alteration has been implicated. Total regression of the lesion occurs in most cases and usually there is no need for surgical intervention. Periorbital lesions require active therapy because of associated visual complications. Segmental hemangioma (affecting particular area of skin) may be associated with underlying anomalies of heart, blood vessels or nervous system. Age and sex: This immature form of capillary hemangioma occurs during infancy. It occurs in almost 2% of newborn population. It is common in premature infants. Females are affected slightly more often than males. Clinical presentation: The lesions usually appear in the first few weeks of life. Infantile hemangioma clinically demonstrates an early period of growth and is usually followed by a stationary period and then, over several years, a phase of slow regression. In the early stage these are flat, red or purple macules which gradually acquire an elevated protruding appearance. The lesion usually reaches its maximum size by 3-6 months. DermAtlas: Image1 ; Image2 ; Image3 ; Image4 Site: Head and neck area, trunk , extremities. Extracutaneous sites include gastrointestinal tract, liver, larynx, pancreas, gall bladder, spleen, central nervous system, adrenal gland, lymph node, urinary bladder and lung. Microscopic features: (ESCOP)Image Links:Image1 Image2 Image3 Image4 Image5 The early lesions display solid, cellular lobules consisting of plump endothelial cells lining tiny rounded vascular spaces with inconspicuous lumina. [Practical clue- At this stage a reticulin stain is useful in demonstrating the connective tissue fibres encircling the tiny vessels ]. Moderate numbers of mitotic figures are present. There may be numerous mast cells in the stroma. Vascular proliferation may involve subcutaneous tissue and may partly or completely replace the fat lobules. (D/D - Angiolipoma). Vascular proliferation is also noted around sweat glands. Perineurial invasion in infantile hemangiomas is a relatively common finding and should not be regarded as evidence of malignancy. Maturation usually commences at the periphery of the lobules and is accompanied by an enlargement of vascular spaces and flattening of the endothelium. The regressed lesions display: progressive fibrosis ; absence of vascular elements; fat replacement of vascular tissue in the subcutis. High endothelial immunoreactivity for the erythrocyte-type glucose transporter protein GLUT1 is a specific feature of juvenile/ infantile hemangiomas during all phases of these lesions. This is a highly selective and diagnostically useful marker for infantile hemangiomas. Cytogenetics:
A locus for an autosomal dominant predisposition has
been identified on chromosome 5q. Infantile hemangiopericytoma: The cells in hemangiopericytoma lie outside the vascular sheath ; in capillary hemangioma these cells are contained within the vascular sheath. A reticulin stain and immunohistochemistry for smooth muscle actin may be useful in establishing the diagnosis. Kaposiform Haemangioendothelioma; Acquired Tufted Hemangioma; Pyogenic granuloma. (Negative for GLUT-1) Congenital Hemangiomas : Occasional "hemangiomas" differ from the infantile form in presenting fully formed at birth, then following a static or rapidly involuting course. RICH (rapidly involuting congenital hemangioma) and NICH (noninvoluting congenital hemangioma). Congenital nonprogressive hemangiomas - Features: Lobules of capillaries set within densely fibrotic stroma containing hemosiderin deposits; focal lobular thrombosis and sclerosis; frequent association with multiple thin-walled vessels; absence of "intermingling" of the neovasculature with normal tissue elements; and lack of immunoreactivity for GLUT1 and LeY.
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