Asymptomatic Papules in a Segmental Pattern over the Back

A 12-year-old boy presented with multiple skin-colored to yellowish papules over the right lower back in a segmental pattern. Biopsy revealed mature adipocytes in the dermis. A diagnosis of nevus lipomatosus cutaneous superficialis was made.

Asymptomatic papules in a segmental pattern over the back

A 13-year-old boy presented with multiple asymptomatic raised papules over the right side of the lower back, which gradually increased in size for the last 5 years. Cutaneous examination revealed multiple skin-colored to yellowish, discrete, and coalescent papules varying in size from 0.5 cm to 2 cm in a segmental pattern. The lesions were soft, non-tender and did not cross the midline [Figure 1]. Systemic examination revealed no abnormalities. Routine hematological and biochemical investigations were normal. Skin biopsy from the papule revealed normal epidermis with islands of adipocytes among the collagen bundles and in the papillary and reticular dermis [Figure 2].

Figure 1.

Multiple skin colored to yellowish papules and coalescent plaques in a segmental pattern over the right back

Figure 2.

Multiple mature adipocytes among the collagen bundles and in the papillary and reticular dermis (H and E, ×200)

Question

What is your diagnosis?

Answer

Nevus lipomatosus cutaneous superficialis (NLCS) of Hoffman and Zurhelle.

Discussion

Nevus lipomatosus cutaneous superficialis (NLCS) is a rare and benign developmental anomaly characterized by mature ectopic adipose tissue in the dermis. It was first described by Hoffman and Zurhelle in 1921 and is now divided in 2 clinical forms.[1] Classical type as described by Hoffman and Zurhelle presents as multiple soft to cerebriform papules or nodules in a segmental or zosteriform pattern that may later coalesce to form plaques.[1,2] The plaques are usually smooth but may appear verrucous or ‘cerebriform.’ The classical form has a predilection for the pelvic girdle, sacral, and lumbar regions. Onset is usually at birth or in childhood. The other type of NLCS is a solitary lesion and is seen most commonly in adults without predilection for any particular site. The sites commonly involved are arms, knees, axilla, ears, and scalp.[2]

The exact pathogenesis of NLCS is unknown, but several theories have been proposed. Adipose tissue metaplasia in the course of degenerative changes in the dermal connective tissue, developmental displacement (heterotopia) of adipose tissue, and possible origin of adipocytes from the walls of the dermal vessels has been documented.[1,3,4]

The diagnosis can be usually made on clinical examination and confirmed on histology. Differential diagnosis includes segmental neurofibromatosis in case of segmental NLCS or giant achrochordon with fat herniation in case of solitary nodule. Histology reveals isolated groups of ectopic mature adipocytes within the papillary and upper reticular dermis. Ultrastructural studies show adipocytes containing large intra-cytoplasmic lipid vacuoles.[4]

The associations of NLCS include cafe-au-lait macules, leukodermic spots, hypertrichosis over the nevus, comedo-like lesions, and angiokeratoma of Fordyce.[4,5]

Treatment is usually sought for cosmetic reasons. Surgical excision or laser ablation may be performed. Excision is curative as recurrence is rare.