Fine Needle Aspiration ofPleomorphic Lipoma of the Neck:Report of Two CasesXiaowei Chen, M.D.,1* Kathy Yu, M.D.,2 Guo-Xia Tong, M.D.,1

Melanie Hood, M.D. (Student),3 Ian Storper, M.D.,2 and Diane Hamele-Bena, M.D.1

Pleomorphic lipoma is a rare lipocytic neoplasm that most com-monly occurs in the head and neck region in middle-aged toelderly men. Clinically, it presents as a slow-growing, well-circumscribed subcutaneous mass. Histopathologically and cyto-genetically, it has some features overlapping with other benignand malignant tumors, such as benign spindle cell lipoma, atypi-cal lipomatous tumor, liposarcoma, and malignant fibrous histio-cytoma. However, cure rates are high when pleomorphic lipomais treated with complete surgical excision with clear margins.Therefore, an accurate preoperative diagnosis is very importantfor proper treatment. Due to the rarity of this tumor, few casesdiagnosed by cytology have been reported in the English litera-ture. Here, we report two cases of pleomorphic lipoma, thediagnoses of which were suggested on fine needle aspirationbiopsies and subsequently confirmed by surgical excisions.Diagn. Cytopathol. 2010;38:184–187. ' 2009 Wiley-Liss, Inc.

Key Words: pleomorphic lipoma; FNA cytology; head andneck; FNAB

Lipomas are by far the most common soft tissue tumors

with an annual incidence of at least 1 per 1,000 in the

general population. Variants include angiolipoma, myoli-

poma, spindle cell lipoma, pleomorphilc lipoma, chon-

droid lipoma, angiomyolipoma, myelolipoma, and benign

lipoblastoma. Pleomorphic lipoma is a rare variant of lip-

oma that typically occurs in the head, neck, shoulder, and

back regions of older men. This tumor is benign and does

not recur or metastasize if completely excised. Therefore,

its recognition is important to avoid unnecessary workup

and extensive surgery.

Report of Two Cases

Case 1

A 56-year-old man presented for workup of a right supra-clavicular neck mass. He had noted the mass for 6 monthswithout any other symptoms. There was no history oftrauma to the local area. MRI with contrast found noevidence of a lesion in the parotid, submandibular region,thyroid, or larynx, and no appreciable lymphadenopathy.Direct laryngoscopy and esophagoscopy were negative. Onphysical examination, palpation confirmed the presence of a1.5 cm well-demarcated mass in the subcutaneous tissue ofthe right neck. The mass was felt to be soft, but slightlyfirmer than normal fatty tissue. Fine needle aspiration(FNA) of the mass was performed using a 25 gauge needleand yielded scant material that appeared fatty upon grossinspection. On-site preliminary microscopic examinationrevealed adipose tissue and few histiocyte-like cells, sug-gesting the diagnosis of lipoma versus fat necrosis.

Case 2

An 83-year-old male with a history of melanoma pre-sented with a 2.5 cm right submandibular mass. He alsohad diminished 5th and 7th cranial nerve function. Hewas referred to the ENT service and an ultrasound-guidedfine needle aspiration biopsy of the mass was performed.Subsequently, a contrast-enhanced MRI of the neck andbrain revealed a 2.2 3 1.6 cm mass anterior to the rightsubmandibular gland and an incidental 1.5 3 8.4 cm leftpara midline posterior spinal lipoma.

Cytologic Findings

Case 1

The smears were stained with Diff-Quik and Papanicolaou

stains. Microscopic examination revealed a few fragments

of mature adipose tissue, few histiocytes, and spindle

cells. In addition, there were scattered large cells with

high nuclear to cytoplasmic ratios and hyperchromatic

nuclei (Fig. C-2A). Some of these larger cells were mono-

1Department of Pathology, Division of Cytopathology, Columbia Uni-versity Medical Center, New York, New York

2Department of Otolaryngology, Columbia University Medical Center,New York, New York

3Medical Student, Columbia University, College of Physician and Sur-geons, New York, New York

*Correspondence to: Xiaowei Chen, M.D., Department of Pathology,Columbia University Medical Center, 630 West 168th Street, VC14-215,New York, NY 10032. E-mail: xc2159@columbia.edu

Received 4 June 2009; Accepted 8 July 2009DOI 10.1002/dc.21171Published online 22 September 2009 in Wiley InterScience (www.

interscience.wiley.com).

184 Diagnostic Cytopathology, Vol 38, No 3 ' 2009 WILEY-LISS, INC.

nuclear, whereas others possessed multiple nuclei

arranged peripherally in wreath-like configurations-so

called ‘‘floret cells’’ (Figs. C-1A and B). No mitoses or

necrosis was identified. On the basis of the clinical pre-

sentation and the cytomorphologic features, we suggested

the diagnosis of pleomorphic lipoma. Excisional biopsy

was recommended for definitive diagnosis.

Case 2

The smears were stained with Diff-Quik stain and showed

spindle and epithelioid cells (Fig. C-3A) and few rosette-

like structures virtually identical to those in the case 1

(Figures C-1B and C). Rare cells contain intranuclear

inclusions. The pattern was that of a spindle cell neo-

plasm, and excisional biopsy was suggested.

Histological Findings

Grossly, the specimen in the case 1 consisted of one piece

of firm, white-pink tissue measuring 1.5 3 1 3 0.8 cm.

and the specimen in case 2 was a round, yellow portion

of soft tissue containing a 2.0 3 2.0 3 1.0 cm palpable

nodule. On cut surface, the nodule is tan-yellow and firm

with well-demarcated borders.

Microscopically, in both cases, there were bands of fi-

brous connective tissue interspersed with mature adipose

tissue, scattered atypical mononuclear cells with large,

hyperchromatic nuclei, and multinucleated floret cells

(Figs. C-2B and 3B). Occasional lipoblasts were identified

in case 1, but no mitoses, necrosis, or areas of prominent

vascularity were noted in either case. Spindle cells were

admixed with a ropey type of collagen in the case 2

(Fig. C-3B, inset). Focal myxoid change was also present

in both cases.

The atypical mononuclear and multinucleated cells

were positive for CD34 and S-100 by immunohistochemi-

cal stains. Cytogenetic study of cases 2 identified loss of

chromosome 13 and 16, and deletion of 17p. In both

cases, the findings supported the cytological impression of

pleomorphic lipoma.

Discussion

Pleomorphic lipoma is a rare soft tissue neoplasm first

described by Shmookler and Enzinger in 1981.1 It most

commonly presents as a small, well circumscribed, pain-

less, subcutaneous mass in the posterior neck, shoulder,

and back region of men older than 45 years.2 This un-

usual neoplasm has also been documented in the tongue,3

orbit,4 bulbar conjunctiva,5 parotid gland,6 oral cavity,7

dermis,8 scalp,9 and breast.10

Cytologically, FNA of pleomorphic lipoma reveals

mature fat, spindle cells, and bizarre pleomorphic giant

cells, including floret cells.11–13 Histologically, there are

five key features: (1) circumscription with encapsulation

(in contrast to liposarcoma), (2) characteristic floret cells,

(3) lack of prominent vascularity, (4) rarity of lipoblasts,

and (5) extremely rare mitotic figures. Pleomorphic

lipoma may also have coarse, birefringent interstitial col-

lagen, and inflammatory cells.14

Immunohistochemically, the large, atypical cells, and

multinucleated floret cells typically stain positive for CD34

and S-100 protein; negative for CD68 and cytokeratin.15

Figs. C-1–C-3. Fig. C-1. Multinucleated ‘‘floret’’ cells in fine needleaspiration biopsy of pleomorphic lipoma. A and C: Diff-Quik, 3400.B and D: Papanicolaou, 3400. Fig. C-2. Cytologic and histologicalcorrelation of case 1. A: FNA biopsy specimen: Fatty material in smearbackground (Diff-Quik, 3100). Inset: Fragment of fibroadipose tissuecontaining cells with hyperchromatic nuclei. (Papanicolaou, 3100).B: Resected tissue specimen: Adipose tissue with interspersed collage-nous tissue containing atypical cells with hyperchromatic nuclei and afloret cell (center) (H&E, 3100). Fig. C-3. Cytologic and histologicalcorrelation of case 2. A: Spindle cells and a multinucleated ‘‘floret’’ cellin fine needle aspiration specimen (Papanicolaou, 3100). Inset: Atypicalcells with pleomorphic nuclei and multinucleation (Diff-Quik, 3400).B: Resected tissue specimen: Adipose tissue with ropey type of collagen,scattered atypical cells, and a floret cell (inset) (H&E, 3100).

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Cytogenetically, pleomorphic lipomas, like most other

soft tissue tumors, have an abnormal karyotype. Most

pleomorphic lipomas show unbalanced aberrations involv-

ing 16q (resulting usually in monosomy 16 or partial loss

of 16q), whereas others show unbalanced aberrations of

13q or present a combination of a 13q abnormality and a

ring chromosome.16

The differential diagnosis of pleomorphic lipoma

includes both benign and malignant soft tissue tumors.

Benign spindle cell lipoma appears clinically similar to

pleomorphic lipoma, also arising in the head and neck

region of men. Some consider pleomorphic lipoma to be

a variant of this entity.2 Histological features of spindle

cell lipoma include mature adipose tissue, varying quanti-

ties of dense birefringent collagen, mast cells, and spindle

cells. However, it lacks the large, cytologically atypical

cells with pleomorphic nuclei and floret cells.17

The distinction between pleomorphic lipoma and well-

differentiated liposarcoma (atypical lipomatous tumor) is

important and may be difficult.18–20 Both neoplasms may

have floret cells and lipoblasts. However, the proportion of

these cells is a clue to the diagnosis: liposarcomas have

more lipoblasts, whereas these cells are much fewer in

pleomorphic lipomas. Myxoid liposarcoma accounts for

45% of all liposarcomas. Like pleomorphic lipoma, it usu-

ally appears after 40 years of age and is more common in

men. It is characterized by sheet-like areas of proliferating

lipoblasts in varying stages of differentiation, a plexiform

capillary pattern most obvious at the tumor edge, and a

myxoid matrix between the vessels and tumor cells. The

lipoblasts have a signet-ring appearance. Scattered spindle

cells, multinucleated lipoblasts, and giant cells may also be

present. Pleomorphic liposarcoma is a highly cellular tu-

mor with extreme nuclear pleomorphism, typically contain-

ing giant lipoblasts with bizarre, hyperchromatic nuclei as

well as necrosis, and hemorrhage.21–23 Myxoid malignant

fibrous histiocytoma is more common in men than in

women and occurs at around 50–70 years of age. However,

it is more often found in the extremities and retroperito-

neum. Grossly, it has a translucent or gelatinous gray

appearance. Histologically, it typically shows a prominent

myxoid stroma, with cellular areas containing a spectrum

of well-differentiated fibroblasts and cells with a high

degree of nuclear pleomorphism, multinucleation, and mi-

totic activity. Classic floret cells are not common.24

Fine needle aspiration biopsy is a quick and simple

procedure in the initial evaluation of palpable masses. In

our case, the cytologic features were sufficiently unique

to suggest the diagnosis of pleomorphic lipoma. This

diagnostic entity should be considered in the differential

diagnosis of soft tissue tumors of the head and neck,

especially when the characteristic clinical and cytologic

features described herein are present. However, FNA is

not definitive, and tissue diagnosis is recommended for

confirmation.12–14 Pleomorphic lipoma is treated with

complete surgical excision with clear margins. Although

these lesions are benign, they may recur if incompletely

excised. Thus, simple enucleation is inadequate and is

therefore not recommended.25 However, if complete

excision is performed; these tumors have a very high-

cure-rate and excellent prognosis. In our cases, FNA find-

ings, combined with the clinical presentation, suggested

the diagnosis of this rare neoplasm and led to appropriate

treatment.

References

1. Shmookler BM, Enzinger FM. Pleomorphic lipoma: A benign tumor

simulating liposarcoma. A clinicopathologic analysis of 48 cases.Cancer 1981;47:126–133.

2. Weiss SW, Goldbum JR. Enzinger and Weiss’s soft tissue tumor.

4th ed. St. Louis, MO: Mosby; 2001. p 598–601.

3. Guillou L, Debon A, Chartin B, Madarnas P. Pleomorphic lipoma

of the tongue: Case report and literature review. J Otolaryngol1986;15:313–316.

4. Daniel CS, Beaconsfield M, Rose GE, Luthert PJ, Heathcote JG,

Clark BJ. Pleomorphic lipoma of the orbit: A case report andreview of literature. Ophthalmology 2003;110:101–105.

5. Bryant J. Pleomorphic lipoma of the bulbar conjunctiva. Ann Oph-

thalmol 1987;19:148–149.

6. Graham CT, Roberts AH, Padel AF. Pleomorphic lipoma of the pa-

rotid gland. J Laryngol Otol 1998;112:202–203.

7. Perrotti V, Rubini C, Fioroni M, Iezzi C. Pleomorphic lipoma of

the oral cavity. Minerva Stomatol 2006;55:321–325.

8. Nigro MA, Chieregato GC, Querci Della Rovere G. Pleomorphic

lipoma of dermis. Br J Dermatol 1987;116:713–717.

9. Bryant J. A pleomorphic lipoma in the scalp. J Dermatol Surg

Oncol 1981;7:323–325.

10. Lopez-Rios F, Alberti N, Perez-Barrios A, De Agustin PP. Aspira-tion biopsy of pleomorphic lipoma of breast. A case report. ActaCytol 2000;44:225–228.

11. Yong M, Raza AS, Greaves TS, Cobb CJ. Fine-needle aspiration ofa pleomorphic lipoma of the head and neck: A case report. DiagnCytopathol 2005;32:110–113.

12. Veiga M, Fresno MF, Madrigal B, Alvarez De Los Heros C. Pleo-morphic lipoma on fine needle aspiration cytology. Acta cytol1998;42:1489–1490.

13. Lopez-Rios F, Alberti N, Perez-Barrios A, De Agustin PP. Fineneedle aspiration of pleomorphic lipoma. Diagn Cytopathol 2001;24:296–297.

14. Mills SE, Carter D, Greenson JK, Oberman HA, Reuter V, StolerMH. Sternberg’s diagnostic surgical pathology. 4th ed. LippincottWilliams & Wilkins; Philadelphia, PA. 2004. p 156.

15. Beham A, Schmil C, Hold S, Fletcher CDM. Spindle cell and pleo-morphic lipoma: An immunohistochemical study and histogeneticanalysis. J Pathol 1989;158:219–222.

16. Fletcher CD, Akerman M, Dal Cin P, et al. Correlation betweenclinicopathological features and karyotype in lipomatous tumors.A report of 178 cases from the Chromosomes and Morphology(CHAMP) Collaborative Study Group. Am J Pathol 1996;148:623–630.

17. Enzinger FM, Harvey DA. Spindle cell lipoma. Cancer 1975;36:1852–1859.

18. Thirumala S, Desai M, Kannan V. Diagnositic pitfalls in fine needleaspiration. Cytology of pleomorphic lipoma. A case report. ActaCytol 2000;44:653–656.

CHEN ET AL.

186 Diagnostic Cytopathology, Vol 38, No 3

Diagnostic Cytopathology DOI 10.1002/dc

19. Rioby HS, Wilson YG, Cawthorn SJ, Ibrahim NB. Fine needle aspi-ration of pleomorphic lipoma: A potential pitfall of cytodiagnosis.Cytopathology 1993;4:55–58.

20. Azzopardi JG, Iocco J, Salm R. Pleomorphic lipoma: A tumor sim-ulating liposarcoma. Histopathology 1983;7:511–523.

21. Minic AJ. Well-differentiated liposarcoma mimicking a pleomorphiclipoma—A case report. J Craniomaxillofac Surg 1993;21:124–126.

22. Shattuck MC, Victor TA. Cytologic features of well-differentiated scle-rosing liposarcoma in aspirated samples. Acta Cytol 1988;32:896–901.

23. Klijanienko J, Caillaud JM, Lagace R. Fine-needle aspirationin liposarcoma: Cytohistologic correlative study including well-differentiated, myxoid, and pleomorphic variants. Diagn Cytopathol2004;30:307–312.

24. Digregorio F, Barr RJ, Fretzin DF. Pleomorphic lipoma. Case report

and review of the literature. J Dermatol Surg Oncol 1992;18:197–

202.

25. Yencha MW, Hodge JJ. Pleomorphic lipoma: Case report and litera-ture review. Dermatol Surg 2000;26:375–380.

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