Case 1 History
The patient is a 1-year-old female who developed a solitary bright red plaque on the scalp that developed rapidly over a few weeks. Closer examination reveals a circumscribed nodule with superficial telangiectasia.
Microscopic Findings
Sections show a dense array of blood vessels in the dermis with scattered small vascular lumina present ( Fig. 17.1 ).
Diagnosis
Infantile Hemangioma
Clinical Presentation
Infantile hemangioma, also called strawberry hemangioma , typically presents as a solitary bright red plaque on the head and neck of an infant shortly after birth. Involution occurs over time but is not absolute, and involvement can produce morbidity associated with location (e.g., periocular) and size.
Histopathology
Histopathology varies depending on the stage. In early involvement, there are sheets of plump endothelial cells with small lumens. As growth progresses, endothelial cells flatten, lumens dilate, and fibrosis increases. Glut-1 immunohistochemistry typically labels the endothelium.
Differential Diagnosis
Considerations include other vascular proliferations such as arteriovenous hemangioma (AVH), cherry hemangioma, and angiokeratoma ( Table 17.1 ).
| Infantile Hemangioma | Arteriovenous Hemangioma | Cherry Hemangioma | Angiokeratoma | |
|---|---|---|---|---|
| Patient age | Typically younger than 1 year | Any age | Adult | Any age |
| Location | Head and neck | Any site | Trunk, often | Genital (Fordyce), acral (Mibelli) |
| Size of vessels | Small caliber and thin walled | Small vessels with muscular walls | Small caliber and thin walled | Small caliber and thin walled |
| Location of vessels | Dermis, subcutis | Dermis | Dermis | Perijunctional dermis |
| Cellularity | High (early lesion) | Low | Low | Low |
Arteriovenous Hemangioma
Clinical Presentation
AVH commonly involves the head and neck or extremities and can present at any age. Presentation in later adulthood is common. AVH presents in solitary fashion.
Histopathology
AVH consists of a circumscribed proliferation of benign endothelial cells lining variably sized vessels in the dermis ( Fig. 17.2 ). A subset of vessels have integrated intramural smooth muscle. The stroma is typically fibrous but may occasionally include lipocytes. Glut-1 expression is absent.
Cherry Hemangioma
Clinical Presentation
Cherry hemangiomas present as small circumscribed red or purple papules, most commonly on the trunk, in adulthood.
Histopathology
Cherry angiomas are papular, domed or sessile proliferations composed of small-caliber vessels with small benign endothelium ( Fig. 17.3 ). Some vascular spaces may be congested. Cherry hemangiomas lack Glut-1 expression.
Angiokeratoma
Clinical Presentation
Angiokeratomas present as red or black papules involving a variety of different sites depending on the clinical scenario: the fingers (Mibelli), scrotum (Fordyce), circumscriptum (more diffuse distribution and presents in early childhood or at birth), and diffuse (syndromic related to X-linked recessive Fabry disease and can involve the skin in a bathing-trunks distribution).
Histopathology
Angiokeratomas characteristically show both epidermal hyperplasia and hyperkeratosis jointly with an increase in vessels ( Fig. 17.4 ). Variably dilated, thin-walled channels reside in close apposition to the acanthotic epidermis. Thrombosis commonly ensues, and recanalization is also common as a secondary consequence. Both the stroma and the stratum corneum may contain erythrocytes as a secondary consequence.
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Infantile hemangioma
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Self-resolving vascular proliferation which progresses from plump high cellularity to formation of dilated vascular spaces with fibrosis.
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Arteriovenous malformation
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Solitary nodule composed of variably sized vascular spaces with muscular walls.
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Cherry angioma
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Solitary nodule composed of dilated capillaries.
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Angiokeratoma
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Red-black exophytic papule with both epidermal hyperplasia and subjacent dilated capillaries.
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