Huge Nevus Lipomatosus Cutaneous Superficialis on Back: An Unusual Presentation.

Nevus lipomatosus cutaneous superficialis (NLCS) is a benign dermatosis, histologically characterized by the presence of mature ectopic adipocytes in the dermis. We hereby report a case of a 10-year-old boy who presented with multiple huge swellings on the scapular regions and lower back. The lesions were surmounted by small papules, along with peau-d orange appearance at places. Histology showed features consistent with NLCS. The case is being reported for the unusual clinical presentation.

What was known?

Nevus lipomatosus cutaneous superficialis is a benign dermatological condition which classically presents as multiple painless soft pedunculated, yellowish cerebriform masses commonly located on the pelvic and gluteal region. Histology shows mature ectopic adipocytes in the dermis.

Introduction

Nevus lipomatosus cutaneous superficialis (NLCS) is a rare benign hamartomatous condition, which usually presents at birth or manifests in the first two decades of life. The classical presentation is with multiple painless soft pedunculated, yellowish cerebriform masses commonly located on the pelvic and gluteal region. The solitary form of NLCS presents as a sessile dome-shaped papule. We report here a case of NLCS with huge swellings on the back and prominent peau-d orange appearance at places.

Case Report

A 10-year-old boy presented with multiple humps on the upper and lower back, present for the preceding 2 years. Starting as a single swelling on the upper back, it gradually increased in number and size to attain the present dimension. The condition was asymptomatic to start with, but lately it was itchy. There was no history of prior trauma or discharge from the lesion. Past medical history and family history were not significant.

Examination revealed two huge dome-shaped tumorous masses over both the scapulae. Similar swellings were present over the lower back as well [Figure 1]. The tumors were soft to firm in consistency and studded with smaller papules. The surface showed fine wrinkling and peau-d orange appearance at places [Figure 2]. Besides, there was induration at places. There were a few smaller satellite nodules in the surrounding skin. There was no evidence of ulceration or comedo-like plugs associated with the lesions. Regional lymphadenopathy was not found. There was no underlying developmental anomaly, cafι-au-lait macule, neurological abnormality or evidence of any systemic disease. Routine laboratory examination of blood was normal. Histological examination showed beneath a normal epidermis, aggregates of mature adipocytes in the upper dermis [Figure 3]. Appendageal structures could not be appreciated. There was normal vascularity and no infiltrate. Based on the clinical and histologic features, a diagnosis of NLCS was made. The patient was counseled and referred to Department of Plastic Surgery but was subsequently lost to follow-up.

Figure 1

Clinical photograph showing two huge dome-shaped tumorous masses over both the scapulae. Note the swellings over the lower back also

Figure 2

Close-up photograph showing fine wrinkling and peau-d orange appearance. Besides, there are smaller satellite nodules in the surrounding skin

Figure 3

Photomicrograph showing a normal epidermis, increased melanization of the basal layer, aggregates of mature adipocytes in the upper dermis, normal vascularity and lack of infiltrate. (H and E, 40×)

Discussion

NLCS is a rare hamartoma that is characterized by the presence of ectopic isolated adipocytes or mature adipose tissue in the dermis.[1] Morphologically, the lesions of classical NLCS are asymptomatic, soft, skin colored to yellow papulo-nodules, often coalescing to form plaques. The surface may be smooth, wrinkled, cerebriform, and associated with comedones and peau d’orange texture. In our case, the lesions showed prominent peau d’orange appearance. Verrucous surface of the lesions has also been reported.[2] The distribution may be linear, systematized, zosteriform or along the lines of skin folds.

The lesions are usually located on the pelvic girdle, lumbar area, buttocks and upper thighs, with rare instances of involvement of the scalp, face, shoulder, thorax and abdomen. Other unusual locations of NLCS include elbow and pinna.[34] The solitary variety of NLCS consists of a solitary papule or nodule. The disorder may coexist with pigmentary conditions like cafe-au-lait macules, hypertrichosis, leukoderma, capillary hemangioma and trichofolliculoma.[56] The etiopathogenesis is not known. However, electron microscopic appearance of lipocytesin in close association with the capillaries suggests hamartomatous origin from the pericytes.[5] Alternatively, adipose metaplasia in the dermal connective tissue may lead to NLCS.[4]

We considered the clinical differential diagnoses of plexiform neurofibroma, smooth muscle hamartoma and leiomyoma cutis. All of them were ruled out by histopathology. The characteristic histopathological finding is the presence of ectopic fat cells in dermis, mostly around blood vessels.[7] Histological differentials include Goltz's syndrome, lipofibromas and giant acrochordons with fat herniation. Goltz syndrome is characterized by the absence of collagen and associated underlying deformities. The pedunculated appearance and later onset in life help to distinguish lipofibroma from nevus lipomatosus. Treatment is generally not required as the lesions are absolutely benign. Systemic abnormalities and malignant changes have not been reported in association with NLCS.

What is new?

Our case had a few unique findings like multiple huge swellings on the back mimicking smooth muscle hamartoma and plexiform neurofibroma, presence of fine wrinkling and peau-d orange appearance at places.