Halo Phenomenon in Lobular Capillary Hemangioma: A Case Report of a Pyogenic Granuloma With Surrounding Cutaneous Hypopigmentation and Review of Tumors With Halo Phenomenon

Abstract

A halo phenomenon describes a skin neoplasm that is surrounded by a hypopigmented or white halo. Halo lesions have been observed in association with an epithelial neoplasm (seborrheic keratosis), a fibrous lesion (surgical scar), a keratinocyte malignancy (basal cell carcinoma), melanocytic neoplasms, and vascular lesions. Benign lesions (café au lait macules and nevi) and malignant tumors (primary and metastatic melanoma) are melanocytic neoplasms that have developed perilesional halos. Halo nevi are a commonly occurring manifestation of a halo phenomenon; however, perilesional hypopigmented halos have also been observed around nevi in patients following treatment with antineoplastic drugs, acquisition of COVID-19 (infection and vaccine), the occurrence of a visceral tumor (including not only melanoma, but also papillary thyroid carcinoma and neuroendocrine cancer of the lung), surgery (such as the excision of a primary melanoma), and Turner syndrome. A halo phenomenon has also been observed in patients with congenital (capillary malformation-arteriovenous malformation and congenital hemangioma) or acquired (angioma, eruptive pseudoangiomatosis, infantile hemangioma, and lobular capillary hemangioma) vascular lesions. In summary, a halo phenomenon can occur in association with primary lesions of various embryologic derivations. Most commonly, they have been observed in around nevi and vascular tumors. Halo lobular capillary hemangioma can be added to the list of acquired vascular lesions with the potential to develop a halo phenomenon. The preservation of melanocytes with loss of melanin pigment expression in the reported patient suggests the possibility that a post-inflammatory etiology may be responsible for the genesis of her halo lobular capillary hemangioma.

Keywords: angioma; capillary; granuloma; halo; hemangioma; hypopigmentation; lobular; nevus; phenomenon; pyogenic.

Figure 1. Clinical presentation of a halo lobular capillary hemangioma on the distal right leg of a 50-year-old Caucasian woman

A 5.0 x 4.0-millimeter red nodule with a white epithelial collarette and surrounding asymmetric hypopigmented patch (within the blue oval) is located on her medial right leg proximal to the ankle. There were two prior episodes of the lesion spontaneously bleeding.

Figure 2. Morphologic appearance of a lobular capillary hemangioma with a perilesional hypopigmented patch

A distant (A) view of the medial right lower extremity proximal to the ankle of a 50-year-old Caucasian woman (within the blue oval) shows a halo lobular capillary hemangioma. A closer view (B) shows an asymmetric hypopigmented patch that surrounds the lesion; its outline is demarcated by the blue arrows. Another closer view (C) shows superficial scaling overlying the erythematous central portion of the lesion and a white epithelial collarette surrounding the lesion; the raised edge of the collarette, at the edge of the vascular tumor, is present between the black arrows.

Figure 3. Lobular capillary hemangioma with halo phenomenon: hematoxylin and eosin-stained central portion of lesion and epidermal collarette

Lower (A and B) and higher (C and D) magnification views show hyperkeratosis (within the blue brackets), acanthosis (within the black brackets), and a collarette of the epithelium (within the black oval). The nodular lesion shows lobules of vascular proliferation (black arrows) within a fibrotic dermal stoma (blue circles) with minimal inflammation. The dermis, both deep and lateral to the vascular tumor, has solar elastosis (black triangles) (hematoxylin and eosin stain: A, x10; B, x10; C, x20; D, x20).

Figure 4. Lobular capillary hemangioma with perilesional halo: hematoxylin and eosin-stained tissue specimen of halo adjacent to the lesion, epidermal collarette, and lateral portion of the lesion

Lower (A and B) and higher (C and D) magnification views show lobules of capillaries and small vessels (black arrows) and minimal accompanying inflammation within a fibrotic dermis (blue circles) in the lateral portion of the hemangioma. The epidermal collarette (within the black oval) surrounds and extends beneath the vascular tumor. There is solar elastosis (black triangles) in the lateral portion of the specimen where the hypopigmented perilesional was clinically observed (hematoxylin and eosin stain: A, x10; B, x10; C, x20; D, x20).

Figure 5. Lobular capillary hemangioma with perilesional halo: hematoxylin and eosin-stained tissue specimen of halo adjacent to the lesion, epidermal collarette, and lateral portion of the lesion

Lower (A and B) and higher (C and D) magnification views show lobules of capillaries and small vessels (black arrows) and minimal accompanying inflammation within a fibrotic dermis (blue circles) in the lateral portion of the hemangioma. The epidermal collarette (within the black oval) surrounds and extends beneath the vascular tumor. There is solar elastosis (black triangles) in the lateral portion of the specimen where the hypopigmented perilesional was clinically observed (hematoxylin and eosin stain: A, x10; B, x10; C, x20; D, x20).

Figure 6. Microscopic examination of the Fontana-Masson-stained halo lobular capillary hemangioma on a 50-year-old woman’s distal medial right leg

The low magnification view of the lobular capillary hemangioma with a perilesional halo shows positive staining with a Fontana-Masson stain in the central portion of the vascular tumor and lateral to the epidermal collarette on both sides of the specimen (cells in the basal layer of the epidermis, found within the black brackets). The Fontana-Masson stain demonstrates the presence of melanin; therefore, the melanin is not shown to be present in the epidermal collarette and the skin, medially and laterally, adjacent to the epidermal collarette on both sides of the specimen (Fontana-Masson stain: x 2).

Figure 7. Lobular capillary hemangioma with halo phenomenon: Fontana-Masson-stained left side of the lesion and perilesional halo

Low (A) and higher (B, C, and D) magnification views of the left side of the Fontana-Masson-stained halo lobular capillary hemangioma do not show melanin in the areas corresponding to the epidermal collarette and the adjacent skin--both medial and lateral to the collarette. Melanin is present, as demonstrated by the positive staining of cells in the basal layer of the epidermis (within the black brackets) at the edges of the specimen and in the center of the vascular lesion (Fontana-Masson stain: A, x4; B, x10; C, x20; D, x40).

Figure 8. Lobular capillary hemangioma with perilesional halo: right side of the lesion and adjacent halo stained with Fontana-Masson stain

Low magnification (A) and higher magnification (B, C, and D) views of the right side of the halo lobular capillary hemangioma stained with the Fontana-Masson stain. Melanin is present in the basal layer cells found in the center of the vascular tumor and in the lateral portion of the specimen (denoted by the black staining of the cells in the basal layer of the epidermis within the black brackets). Melanin expression is absent in the areas of the specimen that show the epidermal collarette (which appeared white) and the adjacent skin (both medial and lateral) to the collarette; the absence of melanin adjacent to the central lesion clinically correlates with the hypopigmented halo that surrounds the vascular tumor (Fontana-Masson stain: A, x4; B, x10; C, x20; D, x40).

Figure 9. Microscopic examination of a 50-year-old woman’s distal medial right leg halo lobular capillary hemangioma stained with melanoma antigen recognized by the T-cell (MART-1) stain

Low magnification view of lobular capillary hemangioma with perilesional halo after staining with melanoma antigen recognized by the T-cell (MART-1) stain, using a red chromogen to demonstrate the positive staining cells, shows individual melanocytes (red arrows) present within the basal layer of the epidermis. The melanocytes are uniformly present not only within the central portion of the vascular tumor but also in the epidermis of the epidermal collarette (which clinically appeared white) and the skin adjacent to the collarette (which clinically presented as a halo surrounding the vascular tumor) (MART-1 stain: x2).

Figure 10. Lobular capillary hemangioma with a halo phenomenon: melanoma antigen recognized by the T-cell (MART-1)-stained left side of the lesion and perilesional halo

Low (A) and higher (B, C, and D) magnification views of the left side of the melanoma antigen recognized by the T-cell (MART-1)-stained halo lobular capillary hemangioma shows red staining cells predominantly in the basal layers of the epidermis (red arrows). MART-1 is an immunoperoxidase stain that demonstrates melanocytes; a red chromogen identifies the positive staining cells. The entire specimen, including the central vascular tumor, the epidermal collarette, and the perilesional tissue, all contain melanocytes that are evenly distributed along the epidermal basal layers (MART-1 stain: A, x4; B, x10; C, x20; D, x40).

Figure 11. Lobular capillary hemangioma with perilesional halo: right side of the lesion and adjacent halo stained with melanoma antigen recognized by the T-cell (MART-1) stain

Low magnification (A) and higher magnification (B, C, and D) views of the right side of the halo lobular capillary hemangioma stained with melanoma antigen recognized by the T-cell (MART-1) stain. Melanocytes are present in the basal layer cells of the vascular tumor and in the lateral portion of the specimen (denoted by the red arrows pointing to the red-staining cells). In contrast to an autoimmune disorder such as vitiligo in which there is both melanin expression and melanocytes are diminished, the halo lobular capillary hemangioma demonstrates the loss of pigmentation but the preservation of melanocytes in the epidermal basal cells that are located in the hypopigmented perilesional halo; this finding is consistent with a post-inflammatory process (MART-1 stain: A, x4; B, x10; C, x20; D, x40).