๐ ็ธฝ็ฎ้ ๏ฝ ๐ ่ฑๆๅๆ๏ผๆฌ็ฏ๏ผ ๏ฝ ๐ ๅฎๆด็ฟป่ญฏ ๏ฝ โญ ็ฒพ่ฏ็ญ่จ
SPITZ NEVUS
SPITZ NEVUSย ย ICD-10: D22.L30
โข Spitz nevus is a benign, dome-shaped, hairless, small (<1 cm in diameter) nodule, most often pink, red, or tan (Fig. 9-9A). There is often a history of recent rapid growth.
โข Incidence is 1.4:100,000 (Australia). Most commonly arises in first two decades. They are dome-shaped, firm, and smooth papules/nodules. They can be pink-red (Fig. 9-9A), tan, brown, dark brown, or even black (Fig. 9-9B); usually distributed on the face and legs.
โข Differential diagnosis includes all pink, tan, or darkly pigmented papules: pyogenic granuloma, hemangioma, molluscum contagiosum, juvenile xanthogranuloma, mastocytoma, dermatofibroma, melanocytic nevi, and nodular melanoma.
โข Dermatopathologyโ: Hyperplasia of the epidermis and melanocytes and dilation of capillaries. Admixed large epithelioid cells, large spindle cells with abundant cytoplasm, and occasional mitotic figures.
โข Histologic examination must be done to confirm the clinical diagnosis. Excision in its entirety is important because the condition recurs in 10% to 15% of all cases in lesions that have not been excised completely. Spitz nevi are benign, but there can be a histologic similarity to melanoma and the histopathologic diagnosis requires the help of an experienced dermatopathologist.
โข Spitz nevi do not usually involute, though some may persist.
โข Synonyms: Pigmented and epithelioid spindle-cell nevus. Decades ago, these were called โjuvenile melanoma.โ
A B
FIGURE 9-9 โข Spitz nevusโ(A) Pink dome-shaped nodule on the cheek of a 25-year-old woman, developing abruptly within the previous 12 months; the lesion can be mistaken for a hemangioma. (B) Pigmented Spitz nevus (also called Reed nevus). A black papule surrounded by a tan macular region developed within a few months on the back of a young female; as such a lesion cannot be distinguished from a nodular melanoma, the lesion was excised and the diagnosis confirmed histologically.