Arborizing and Stellate Melanosis: A Rare Entity but Important to Recognize

Mansoura Dermatology and Leprosy Hospital, Egypt

*Corresponding author: Hany Salah Soliman, Mansoura Dermatology and Leprosy Hospital, Egypt, Phone: +201061732403,  EMail: [email protected]

Received Date: July 02, 2026
Published Date: July 28, 2026

Citation: Soliman HS. (2026). Arborizing and Stellate Melanosis: A Rare Entity but Important to Recognize, and Hippocampal Atrophy. Mathews J Case Rep. 11(3):230.

Copyright: Soliman HS. © (2026). 

ABSTRACT

A 52 years old female presented with asymptomatic hyperpigmented patches on the neck present since 10 years .on examination, Intermittent arborizing lines in various lengths and tiny stellate brownish macules over the both sides of the neck (Figure 1A,B).Other flexural areas were uninvolved. There were no systemic abnormalities or family histories of inherited disease There was no history of prolonged exposure to ultraviolet. There was no involvement of the hair, nail and mucous membranes. Dermatoscopy of the lesions showed pigmented dots and globules over the Langer's lines (Figure 1C). Histopathology of the lesions shows epidermal atrophy, flattening of rete ridges, and increased basal hyperpigmentation with melanophages in the dermis (Figure 1D]. The clinical and pathological features above were not consistent with any pigmentary skin disorders. So,The diagnosis of arborizing and stellate melanosis (ASM) was made. In our case, the lesions are exclusively distributed in the neck, unlike the only published case of ASM by Zhang Y, Tan C, which showed distribution in both the neck and upper chest.

DISCUSSION

Arborizing and stellate melanosis (ASM) is novel entity with unknown precise pathogenesis. it appears in adolescents or young adults and persists for years without spontaneous resolution. It has a predilection for the low jaw area, the neck ,and the upper chest [1].The lesions are characterized by intermittent arborizing lines and tiny stellate brownish macules over the skin cleavage line [2]. Differential diagnoses include other skin conditions on the neck with reticular hyperpigmentation, including dyskeratosis congenital (DC), Naegeli–Franceschetti–Jadassohn syndrome (NFJS), Dowling–Degos disease (DDD), Dermatopathia Reticularis Pigmentosa (DRP) and reticulate acropigmentation of Dohi [2,3]. Since our patient did not exhibit the classic triad of reticulate hyperpigmentation, nail dystrophy, and leukoplakia, the diagnosis of DC was excluded. pigmentation changes in NFJS appear on the trunk. The lack of enamel abnormalities, hypohidrosis, and palmoplantar keratoderma contradicted the NFJS diagnosis. Our case is histologically different from DDD. DRP is characterized by universal reticulate hyperpigmentation, non-cicatricial alopecia, palmoplantar keratoderma, hypohidrosis, and onychodystrophy. Reticulate acropigmentation of Dohi has its distribution on the dorsal hands and feet (Figure 1A-1C).

Figure 1A: Arborizing hyperpigmented lines on the left side of neck over the skin cleavage

Figure 1B: Arborizing hyperpigmented lines on the right side of neck over the skin cleavage

Figure 1C: Dermatoscopy of the lesions showed pigmented dots and globules over the Langer's lines

Figure 1D: Histopathology showing Epidermal atrophy, flattening of rete ridges, basilar hyperpigmentation, and dermal melanophages (H&E×100)

CONCLUSION

Arborizing and stellate melanosis (ASM) is perhaps a novel entity. It should be considered in the differential diagnosis of the conditions with reticular or rippling hyperpigmentation affecting the neck and upper chest.

REFERENCES

1. Zhang Y, Tan C. (2022). Arborizing and stellate melanosis: Proposal and description of a novel entity. Journal of Cosmetic Dermatology. 21(9):4084-486.
2. Muller CS, Tremezaygues L, Pfohler C, Vogt T. (2012). The spectrum of reticulate pigment disorders of the skin revisited. European Journal of Dermatology. 22(5):596- 604.
3. Itin PH, Lautenschlager S. (1998). Genodermatosis with reticulate, patchy and mottled pigmentation of the neck– a clue to rare dermatologic disorders. Dermatology. 197(3):281- 290.