A case of ‘fat-free’ pleomorphic lipoma occurring in the upper back and axilla simultaneously

Abstract

Pleomorphic lipoma is a rare neoplasm that predominantly occurs in the dermis or subcutis of the posterior neck, upper back, and shoulders. Although pleomorphic lipoma is a benign tumor, it may contain atypical cells. As a variant of spindle cell lipoma, pleomorphic lipoma clinically presents as a slow-growing and well-circumscribed subcutaneous mass. Rarely, some patients have multiple lesions. Histologically, pleomorphic lipoma is composed of mature fat, bland spindle-shaped mesenchymal cells, and coarse ‘rope-like’ collagen bands. In addition, lipoma contains multinucleated floret-like giant cells. Although spindle cell lipoma/pleomorphic lipoma with little fat was seen in the original series described by Enzinger and Harvey, cases with little to no fat remain diagnostically challenging. Herein, we report a case of ‘fat-free’ pleomorphic lipoma occurring in the upper back and axilla simultaneously. Although the lipoma was typically composed of bland spindle-shaped cells, rope-like collagen, scattered floret-like giant cells, and striking stromal myxoid change in the background, mature fat was absent. Immunohistochemical analyses showed positive staining for CD34, vimentin, and Bcl-2, and negative staining for S100, confirming the diagnosis of pleomorphic lipoma.

Pleomorphic lipoma in the anterior mediastinum: A case report

“…Their clinical manifestations are also similar: The male-to-female incidence ratio is approximately 4:1, age at onset is 50 years or above, and they primarily occur in the superficial subcutaneous compartments of the neck, shoulders, and back. This unusual neoplasm has also been documented in the tongue, orbit, bulbar conjunctiva, parotid gland, oral cavity, dermis, scalp, and breasts[6]. In the present case, the patient discovered the disease a year ago, and there was no change in the tumor during the 1-year follow-up period.…”

Spindle Cell Lipoma Occurring in the Buccal Mucosa: An Unusual Location of This Benign Lipomatous Neoplasm

“…This infiltration occurs probably due to facial anatomical features, which involve poorly demarcated fascial planes [ 7 ]. SCL is generally solitary, although patients with bilateral SCLs of the tongue [ 8 , 9 ] and nose [ 7 ] and lesions located simultaneously in upper region of the back and axilla [ 10 ] have been reported. Multiple SCLs may be familial or nonfamilial [ 11 ].…”

Pleomorphic lipoma: A gentle giant of pathology

“…[ 4 ] It is reported to be four times more common in males, in the age group of 50-70 years. [ 1 ] Only 10% of tumors occur in females. Our patient was an elderly lady.…”

“…The most typical location is the subcutaneous tissue in the head and neck region. However, few unusual sites have been reported such as the tonsillar fossa, orbit, and tongue[ 1 ] and very few in the intramuscular compartment. [ 2 3 ] In our case, the site was the shoulder, which is typical; however, the intramuscular location was unusual.…”

“…Spindle cell/pleomorphic lipoma is a relatively rare adipocytic neoplasm, which occurs predominantly in male patients aged 50-70 years. [ 1 ] In most cases, it is detected in the subcutaneous tissues of the neck or shoulder. To the best of our knowledge, only five cases have been reported in which the lesion was intramuscular, the last one being a rare occurrence of spindle cell lipoma within an intramuscular lipoma.…”