Nevus lipomatosus cutaneous superficialis of the groin arising in the fifth decade of life

Journal of Drugs in Dermatology, August, 2008 by M.R. Namazi

ABSTRACT: Nevus lipomatosus cutaneous superficialis (NLCS) is a rare malformation characterized by ectopic adipose tissue in the dermis. The lesson is usually present from birth or noticed in the first 2 decades of life. It occurs as sessile or pedunculated, domed nodular growths with a smooth, wrinkled, or cerebriform surface. Multiple lesions have a marked predilection for the gluteal region, lower back, and upper thigh, though solitary lesions may occur at unusual sites like the scalp, clitoris, and calf. An unusual case of NLCS is presented here where the solitary lesion occurred as a large exophytic growth arising at the groin in the fifth decade of life.

INTRODUCTION

Nevus lipomatosus cutaneous superficialis (NLCS) is a rare idiopathic abnormality classically presenting as a clustered group of soft, fleshy, skin-colored or yellowish nodules, usually on the buttocks, abdomen, or back. The nodules are sessile or pedunculated, domed growths with a smooth, wrinkled, or cerebriform surface. (1), (2) The nodules usually develop during the first 2 decades of life, but may be present at birth. The histopathological hallmark is the dermal collection of adipose tissue. (3) Herein, a case of NLCS having some unusual features is described.

CASE REPORT

A 51-year-old female presented with a large tumoral outgrowth on her left groin. The lesion appeared about 4 years prior as a small papule and gradually grew to its present size. On examination, there was a large, relatively soft, asymptomatic, flesh-colored outgrowth overlying the left groin. An annular ulceration was present over the lesion (Figure 1). A general cutaneous examination as well as a systemic examination was unremarkable. A microscopic examination showed mature fat cells distributing throughout, and replacing much of, the dermis. The boundary between the dermis and subcutaneous fat was lost. The overlying epidermis was acanthotic with an area of ulceration, vascular proliferation, and mild inflammatory infiltration. In some areas, fat cells extended as high as the papillary dermis. The lesion was not surrounded by the capsule in any part (Figure 2). It was diagnosed as NLCS.

DISCUSSION

Nevus lipomatosus cutaneous superficialis (NLCS) is a rare malformation characterized by ectopic adipose tissue in the dermis. The proportion of fatty tissue in the dermis varies greatly, and can be as high as 50%. (3) Intradermal melanocytic nevus and Goltz syndrome also show similar histopathological features, but can easily be clinically distinguished from NLCS. The condition was first described by Hoffman and Zurhelle in 1921. (1), (4) Few cases have been reported thereafter.

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The lesion is usually present since birth or noticed in the first 2 decades of life, with no sex prediction. Clinically, it can appear as multiple or solitary, soft, skin-colored papules sometimes coalescing to form plaques with a cerebriform surface. Multiple lesions are seen more commonly in younger patients while a solitary lesion is generally seen in those over 20 years of age. It could be that a solitary lesion is ignored in childhood as a nonspecific hamartomatous lesion or that those with solitary asymptomatic lesions tend to present later in the 20s for cosmetic reasons. The multiple lesions have a marked predilection for the gluteal region, lower back, and upper thigh, though solitary lesions may occur at unusual sites like the scalp, clitoris, and calf. (1), (2), (4)

Many theories have been postulated regarding the histogenesis of this lesion. Hoffman and Zurhelle postulated that fat deposition in the dermis is secondary to degenerative changes in the connective tissue. Other theories reveal that the fat cells represented a true nevus that resulted from the focal heterotropic development of adipose tissue, which may occur during embryonal development. Holtz, in 1955, opined that primitive preadipose tissue grows from the mononuclear cells, which were differentiating lipoblasts around the capillaries. This was supported by an electron microscopic study demonstrating fat cells in close proximity to blood vessels. (4), (5) There are reports of hairy lesions as well as lesions with comedo-like plugs. (1), (2) They are sometimes associated with cafe-au-lait and hypopigmented macules. (1) Unusual features such as large size, extension beyond the midline, and ulceration have been reported in 1 case from India. (6) Pedunculated lipofibroma is a relatively rare form of NLCS. The lesions are large, slow growing, pedunculated tumors. Histologically, groups and strands of fat cells are found embedded among the collagen bundles of the dermis. (7)

CONCLUSION

This case was unusual because the lesion occurred as a large exophytic growth, arose at an atypical site, and did not appear until the fifth decade of life.

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REFERENCES

(1.) Das JK, Sengupta S, Gangopadhyay AK. Nevus lipomatosus superficialis over neck, an atypical site. Indian J. Dermatol Venereol Leprol. 2006; 72:66-67.

(2.) Meena RS, Khare AK, Rana S, et al. Nevus lipomatosus cutaneus superficialis. Indian J Dermatol. 2004; 49:42-43.