A Case of Nevus Lipomatosus Superficialis with Features of a Spindle Cell Lipoma

Roxanne Rajaii, MS, DO1; Nicky Gazy, BS2; Megan Hakim, PA-C3; Sean Stephenson, DO4 1 Beaumont Health Systems -- Farmington Hills Campus; Farmington Hills, Michigan

2 Western University of Health Sciences – Pomona, California 3 Affiliated Troy Dermatologists -- Troy, Michigan

4 Dermatopathology Laboratory of Central States -- Troy, Michigan

Figure 1: Clinical photograph of lesion prior to

biopsy.

ABSTRACT Nevus lipomatosus superficialis (NLS) and spindle cell lipoma (SCL) are both relatively rare benign

neoplasms. NLS can be further subdivided into two clinical types: the classical type and the solitary type.

The classical type typically presents in the lumbosacral area at birth or within the first three decades of life

as multiple soft, non-tender papules or nodules, which commonly coalesce to form plaques. The solitary

form has no location preference and usually occurs later in life as a nodular lesion. A SCL is usually found

in the subcutaneous tissues, with rare intradermal cases reported in the literature. This neoplasm most

commonly occurs on the neck, shoulders, or back of middle-aged to elderly males as a subcutaneous

nodule. In this case report, the authors present a rare and interesting presentation of a NLS with co-

existing features of a dermal SCL.

CASE REPORT A sixty-two-year-old male presented with a chief complaint of an asymptomatic, enlarging growth located

on the left lower extremity that had been present for approximately three years. He denied associated

symptoms including pain, tenderness, pruritus, bleeding, ulceration, and discharge. Furthermore, he

denied any previous evaluation and treatment of the lesion. Patient reported no prior personal or family

history of skin cancer.

On examination, the patient was a Fitzpatrick skin type II with a solitary 1.5 cm skin-colored to pink

pedunculated papule on the left proximal posterior thigh as shown in Figure 1. A shave biopsy of the

lesion was performed and a differential diagnosis included neurofibroma, benign intradermal nevus,

fibroepithelial polyp, basal cell carcinoma, and amelanotic melanoma.

Histologic sections demonstrated a pedunculated papule with basket-weave stratum corneum and a

relatively normal appearance to the epidermis. Within the dermis, relatively normal collagen bundles with

an increase in fibroblasts within the superficial dermis were observed. Of note, lobular aggregations of

adipocytes were found to be replacing much of the dermis with many areas of the adipocytes showing

spindle cells and abundant mucin (Figures 2a-c). Based on the histology, a diagnosis of nevus

lipomatosus superficialis with features of a spindle cell lipoma was made. Due to the benign nature of this

entity, no further treatment was necessary or recommended. Excision was discussed with the patient in

case of recurrence of the lesion, if desired.

DISCUSSION Nevus lipomatous superficialis (NLS) is a benign hamartomatous condition characterized by ectopic

adipocytes in the dermis. The condition is divided into two clinical presentations; the classical Hoffman-

Zurhelle subtype and the solitary subtype.1,9 In the classical Hoffman-Zurhelle subtype, clusters of soft

skin-colored or yellowish papulonodules or plaques may be appreciated. In the solitary subtype, lesions

present later in life as a single dome-shaped or sessile papule. The classical subtype most commonly

presents in the pelvic or gluteal region at birth or within the first three to four decades of life. In contrast,

there is no site predilection for the solitary subtype.5

CONCLUSION In conclusion, nevus lipomatosus superficialis (NLS) is a relatively uncommon hamartomatous neoplasm. A

high index of suspicion, along with histopathological correlation, is needed to diagnose this benign

condition. Even more uncommon are features of a spindle cell lipoma, another rare benign tumor, within a

NLS. The authors present such a case of a rare solitary-type adult-onset NLS with features of a SCL, one

of only a few cases documented in the literature to date.

REFERENCES 1. Buch AC, Panicker NK, Karve PP. Solitary nevus lipomatosus cutaneous superficialis. J Postgrad Med. 2005;51:47–8. 2. Dhamija A, Meherda A, D’Souza P, Meena RS. Nevus lipomatosus cutaneous superficialis: An unusual presentation. Indian Dermatology Online Journal.

2012;3(3):196-198.

3. Dhar S, Kumar B, Kaur I. Naevus lipomatosus superficialis of Hoffman and Zurhelle. Indian J Dermatol Venereol Leprol. 1994;60:39–40.

4. French CA, Mentzel T, Kutzner H, Fletcher CD. Intradermal spindle cell/pleomorphic lipoma: a distinct subset. Am J Dermatopathol. 2000;22:496–502.

5. Goucha S, Khaled A, Zéglaoui F, Rammeh S, Zermani R, Fazaa B. Nevus lipomatosus cutaneous superficialis: Report of eight cases. Dermatology and

Therapy. 2011;1(2):25-30.

6. Khandpur S, Nagpal SA, Chandra S, Sharma VK, Kaushal S, Safaya R. Giant nevus lipomatosus cutaneous superficialis. Indian J Dermatol Venereol

Leprol. 2009;75:407–8.

7. Machol JA, Cusic JG, O’Connor EA, Sanger JR, Matloub HS. Spindle Cell Lipoma of the Neck: Review of the Literature and Case Report. Plastic and

Reconstructive Surgery Global Open. 2015;3(11):e550.

8. Val-Bernal JF, Hermana S. Dermal plexiform spindle cell lipoma. Rom J Morphol Embryol. 2016;57:875-878.

9. Yap FB. Nevus lipomatosus superficialis. Singapore Med J. 2009;50:e161–2.

NLS may be differentiated from other entities in the differential diagnosis such as nevus sebaceous,

neurofibromas, fibrolipomas, hemangiomas, lymphangiomas by clinical presentation, and definitively

by histology. Histopathology of NLS shows a dermal proliferation of mature adipocytes that may be

connected to the subcutaneous tissue or separated from the subcutis by collagen.2 The adipocytes

may present solitarily between collagen bundles or form aggregates around blood vessels or eccrine

glands. Infrequently, spindle cells representing immature fat cells may be present. Cases of co-

existing café-au-lait macules, scattered leukoderma, hypertrichosis, and comedo-like lesions within a

NLS have been reported.3,6

A spindle cell lipoma (SCL), and its pleomorphic subtype, in contrast to NLS, most commonly

presents in the fourth to seventh decade of life as a well-circumscribed mass in the subcutaneous

tissue of the upper back, posterior neck, or shoulders.7 Diagnosis of SCL and the pleomorphic

subtype requires mature fat cells, spindle cells, and strands of strongly eosinophilic collagen.7

Although SCL typically arises in subcutaneous tissue, rare cases of SCL and the pleomorphic

subtype occurring within the dermis have been reported. The dermal SCL and pleomorphic lesions

differ from the classic SCL as they are poorly circumscribed and unencapsulated.4 In addition, the

dermal variant of a SCL may not have a predilection for any specific site or may have a slight

predilection for the thigh-buttocks-groin area.8

Our case highlights a rare and interesting presentation of a NLS with co-existing features of a dermal

SCL, one of only a few reported in the literature. Neither NLS or SCL have concern for systemic

involvement or malignancy. Therefore, treatment is not necessary for any reason other than

cosmesis, and excision is curative with rare recurrence. Rarely, these lesions may ulcerate with

associated foul-smelling discharge. In such instances, surgical excision may be warranted.1,2

Figures 2 a-c: Histopathology at 1x (top image) and 10x (middle

and bottom images) magnification.