Low-Fat Plexiform Spindle Cell Lipoma with Prominent Myxoid

Brief Clinical Studies The Journal of Craniofacial Surgery Volume 28, Number 2, March 2017

In conclusion, we suggest that even the large ACC defects could 20. Ross DA, Laurie SWS, Coombs CJ, et al. Aplasia cutis congenita: failed be managed conservatively with proper care. With the proper conservative treatment. Plast Reconstr Surg 1995;95:124–129 dressing, infection control with no serious complications and 21. Kim CS, Tatum SA, Rodziewicz G. Scalp aplasia cutis congenita complete healing of the defect could be achieved. We also suggest presenting with sagittal sinus hemorrhage. Arch Otolaryngol Head that topical application of bFGF which has positive effects over Neck Surg 2001;127:71–74 wound healing decreases the time of hospitalization with superior 22. Tsuboi R, Rifkin DB. Recombinant basic fibroblast growth factor stimulates wound healing in healing-impaired db/db mice. J Exp wound healing compared to treatment without such application and Med 1990;172:245–251 should be used in order to provide more data for a better treatment 23. Akita S, Akino K, Imaizumi T, et al. The quality of pediatric burn scars modality of the condition. Individual assessment of the patients with is improved by early administration of basic fibroblast growth factor. J an experienced team of good communication including pedia- Burn Care Res 2006;27:333–338 tricians, plastic surgeons, and neurosurgeons in order to provide 24. Hayashida K, Akita S. Quality of pediatric second-degree burn wound the best treatment should be made. Recognizing the complications scars following the application of basic fibroblast growth factor: results due to the mortality associated and knowledge of prevention is of a randomized, controlled pilot study. Ostomy Wound Manage essential for an ideal management. 2012;58:32–36 25. Akita S, Akino K, Imaizumi T, et al. Basic fibroblast growth factor accelerates and improves second-degree burn wound healing. Wound Repair Regen 2008;16:635–641 REFERENCES 26. Maeda T, Oyama A, Funayama E, et al. Successful conservative 1. Browning JA. Aplasia cutis congenital: approach to evaluation and management of a large congenital scalp and skull defect. J management. Dermatol Ther 2013;26:439–444 Craniofac Surg 2015;26:275–277 2. Komuro Y, Yanai A, Seno H, et al. Surgical treatment of aplasia cutis 27. Jung WK, Koo HC, Kim KW, et al. Antibacterial activity and congenita of the scalp associated with bilateral coronal synostosis. mechanism of action of the silver ion in Staphylococcus aureus J Craniofac Surg 2002;13:513–519 and Escherichia coli. Appl Environ Microbiol 2008;74:2171–2178 3. Bernbeck B, Schwabe J, Groninger A, et al. Aplasia cutis congenita of the scalp: how much therapy is necessary in large defects? Acta Paediatr 2005;94:758–760 4. Demmel U. Clinical aspects of congenital skin defects. I. Congenital skin defects on the head of the newborn. Eur J Pediatr 1975;121:21–50 5. Stephan MJ, Smith DW, Ponzi JW, et al. Origin of scalp vertex aplasia cutis. J Pediatr 1982;101:850–853 Low-Fat Plexiform Spindle Cell 6. Winston KR, Ketch LL. Aplasia cutis congenita of the scalp, composite type: the criticality and inseparability of neurosurgical and plastic Lipoma With Prominent Myxoid surgical management. Pediatr Neurosurg 2016;51:111–120 7. Fro¨jd V, Maltese G, Ko¨lby L, et al. Conservative healing of an 11 9- Stroma: An Unusual Oral cm aplasia cutis congenita of the scalp with bone defect. J Neurol Surg Rep 2014;75:220–223 Presentation and 8. Rocha D, Rodrigues J, Marques JS, et al. Aplasia cutis congenita: a conservative approach of a case with large, extensive skin, and Immunohistochemical Analysis underlying skull defect. Clin Case Rep 2015;3:841–844 9. Basterzi Y, Bagdatoglu C, Sari A, et al. Aplasia cutis congenita of Jessica Luana dos Santos, DDS, MSc, the scalp and calvarium: conservative wound management with Eduardo Akira Ocamoto, DDS,y novel wound dressing materials. J Craniofac Surg 2007;18: Luciana Yamamoto Almeida, DDS, PhD,z 427–429 Lucas Ribeiro Teixeira, DDS,§ Alfredo Ribeiro-Silva, MD, PhD, 10. Dutra LB, Pereira M, Kreniski TM, et al. Aplasia cutis congenita: § management of a large skull defect with acrania. J Craniofac Surg and Jorge Esquiche Leo´n, DDS, PhD 2009;20:1288–1292 11. Gospodarowicz D. Biological activities of fibroblast growth factors. Ann Abstract: Spindle cell lipoma (SCL) and pleomorphic lipoma N Y Acad Sci 1991;638:1–8 constitute a spectrum of lipomatous lesions with distinctive clin- 12. Hayek A, Culler FL, Beattie GM, et al. An in vivo model for study of the icopathological features. Multiple variants of SCL have been angiogenic effects of basic fibroblast growth factor. Biochem Biophys Res Commun 1987;147:876–880 reported including fibrous, plexiform, vascular, pseudoangioma- 13. Puvabanditsin S, February M, Garrow E, et al. Our experience with a tous, low-fat/fat-free, and myxoid changes. This paper describes an severe case of aplasia cutis congenita with a large skull defect. Int J Dermatol 2016;55:1151–1153 From the Department of Pathology and Forensic Medicine, Ribeira˜o Preto 14. Rhee ST, Colville C, Buchman SR, et al. Complete osseous regeneration Medical School (FMRP/USP), University of Sa˜o Paulo (USP), Ribeira˜o of a large skull defect in a patient with cutis aplasia: a conservative Preto; yPublic Health Service, Jaboticabal; zHematology Division, approach. J Craniofac Surg 2002;13:497–500 Department of Clinical Medicine, Ribeira˜o Preto Medical School 15. de Oliveira RS, Juca´ CEB, Lins-Neto AL, et al. Aplasia cutis congenita (FMRP/USP), University of Sa˜o Paulo (USP), Ribeira˜o Preto; and §Oral of the scalp: is there a better treatment strategy? Childs Nerv Syst Pathology, Department of Stomatology, Public Oral Health, and Foren- 2006;22:1072–1079 sic Dentistry, University of Sa˜o Paulo, School of Dentistry of Ribeira˜o 16. Ingall NW. Congenital defects of the scalp; studies in pathology of Preto (FORP/USP), University of Sa˜o Paulo, Ribeira˜o Preto, Brazil. development. Am J Obstet Gynecol 1933;25:861–873 Received August 16, 2016. 17. Rudolph RI, Schwartz W, Leyden II. Bitemporal aplasia cutis congenita. Accepted for publication October 7, 2016. Occurrence with other cutaneous abnormalities. Arch Dermatol Address correspondence and reprint requests to Jessica Luana dos Santos, 1974;110:615–618 DDS, MSc, Universidade de Sa˜o Paulo, Avenida Bandeirantes, S/N, 18. Burkhead A, Poindexter G, Morrell DS. A case of extensive aplasia cutis 14040-904, Ribeira˜o Preto, Brazil; congenita with underlying skull defect and central nervous system E-mail: [email protected] malformation: discussion of large skin defects, complications, treatment The authors report no conflicts of interest. and outcome. J Perinatol 2009;29:582–584 Copyright # 2016 by Mutaz B. Habal, MD 19. Frieden IJ. Aplasia cutis congenita: a clinical review and proposal for ISSN: 1049-2275 classification. J Am Acad Dermatol 1986;14:646–660 DOI: 10.1097/SCS.0000000000003348 e158 # 2017 Mutaz B. Habal, MD Copyright © 2017 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited. The Journal of Craniofacial Surgery Volume 28, Number 2, March 2017 Brief Clinical Studies unusual patient with a 1-cm submucosal nodular lesion excised from the buccal mucosa of a 55-year-old woman with classic histopathological and immunohistochemical features of ‘‘low- fat’’ plexiform SCL with prominent myxoid stroma, which initially suggested a soft-tissue myxomatous lesion other than SCL. The current lesion exhibited microscopically few adipocytes supported by network-like myxoid proliferations with retraction artifacts from the surrounding stromal connective tissue. Immunohistochemistry was positive for vimentin, CD34, CD10, and S100, the latter only on adipocytes. The Ki-67 was <1%. Pan-cytokeratin (AE1/AE3), desmin, alpha-SMA, EMA, bcl-2, p53, and remarkably retinoblas- toma protein (pRb) were negative. ‘‘Low-fat’’ plexiform SCL bear no significant prognostic significance, but this lesion may challenge the diagnosis even experienced pathologists.

Key Words: Immunohistochemistry, low-fat lipoma, oral cavity, plexiform variant, spindle cell lipoma FIGURE 2. (A) Microscopic view showing a lobulated mass, containing net-like pindle-cell lipoma (SCL) is a distinct histological variant of proliferations (H&E staining, 2.5). (B) Microscopic view showing a myxoid stroma and scarce adipocytes. Inset shows cellular details of mast cells (H&E S lipoma which is derived from prelipoblastic mesenchymal staining, 20). (C) Microscopic view exhibiting network-like myxoid 1 cells. Spindle cell lipoma is a circumscribed subcutaneous lesion, proliferations presenting retraction artifacts () from the surrounding stromal typically occurring on the neck and upper back of male individuals, fibrosis (arrow) (H&E staining, 10). (D) Presence of mast cells by toluidine blue and it is composed of an admixture of well-aligned spindle cells, staining, 40. Inset shows cellular details of mast cells. mature adipocytes, dense collagen bundles, myxoid interstitial matrix, mast cells, and blood vessels.2,3 Mitoses are extremely rare. While the presence of myxoid matrix is not uncommon, the Following surgical excision, the specimen was fixed in 10% relative proportions of spindle cells and adipocytic elements vary buffered formalin, routinely processed, and embedded in paraffin from SCL patient to patient and it can be designated as ‘‘low-fat’’ or wax. The 3-mm thick sections were stained with hematoxylin and ‘‘free-fat’’ if has a very small amount of adipocytes (<5%) or is eosin. Additional sections were cut for immunohistochemical pro- absent, respectively.4–6 Moreover, 6 patients with dermal SCL have cedures. Immunohistochemical studies were performed using the been reported, often affecting middle-aged females, which micro- following antibodies: Pan-cytokeratin (AE1/AE3), EMA, vimentin, scopically exhibited a moderately circumscribed plexiform pattern, S100, alpha-SMA, desmin, CD10, CD30, CD34, bcl-2, p53, Ki-67, with net-like proliferations and retraction artifacts against the and retinoblastoma protein (pRb). surrounding stromal fibrosis.7 To the best of our knowledge, Histologically, the lesion consisted of a relatively well-circum- ‘‘low-fat/free-fat’’ or plexiform variants of SCL has not been scribed large soft-tissue mass containing variable fibrous connec- reported in the oral cavity. Thus, a ‘‘low-fat’’ variant of lipoma tive tissue interspersed with network-like myxoid proliferations can represent a diagnostic challenge to pathologists, given its often presenting retraction artifacts from the surrounding stromal infrequent presentation as a lesion containing little or no adipocytes, fibrosis (Fig. 2). Furthermore, it was observed variable amount of and can be mistaken as reactive myxoid stromal change, fatty spindle cells, some adipocytes and numerous mast cells in a stroma metaplasia or soft-tissue myxomatous lesions other that SCL.8 of connective tissue presenting ropey collagen fibers bundles. Immunohistochemistry was positive for vimentin, CD34, CD10, and S100, the latter only on adipocytes. The Ki-67 was <1%. Pan- CLINICAL REPORT cytokeratin, desmin, alpha-SMA, EMA, bcl-2, p53, and remarkably A 55-year-old black female was referred complaining of a left-sided pRb were negative (Fig. 3). After 2 months of follow-up, no swelling in the buccal mucosa. The lesion had appeared 3-month recurrence or alteration was detected (Fig. 1B). previously, growing slowly and without any accompanying symp- toms (Fig. 1A). Clinical examination of oral mucosa revealed a well-circumscribed nodule with about 1 cm in diameter. The nodule had fibrous consistency, smooth surface, and it was covered by undamaged oral mucosa. The clinical hypothesis was fibrous hyperplasia or benign mesenchymal neoplasm.

FIGURE 3. Immunohistochemical features. (A) Uniform strong positivity for CD34. (B) S100 positive only in mature adipocytes. (C) Vimentin is strongly FIGURE 1. Intraoral growth on the left buccal mucosa. (A) Preoperative view. positive. (D) Positivity for CD10 was also observed. (E) Negative pRb (B) Follow-up at 2 months. immunostaining. (F) Ki-67 labeling index was <1%.

# 2017 Mutaz B. Habal, MD e159 Copyright © 2017 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited. Brief Clinical Studies The Journal of Craniofacial Surgery Volume 28, Number 2, March 2017

DISCUSSION REFERENCES Spindle cell lipoma was described as a specific entity in 1975 by 1. Piatteli A, Rubini C, Fioroni M, et al. Spindle-cell lipoma of the cheek: a Enzinger and Harvey.9 These authors reported 114 patients and case report. Oral Oncol 2000;36:495–496 described a range of microscopic features, from mature adipose 2. Billings SD, Henley JD, Summerlin DJ, et al. Spindle cell lipoma of the tissue with mucinous material and scattered spindle cells to a oral cavity. Am J Dermatopathol 2006;28:28–31 3. Jaeger F, Capistrano HM, Castro WH, et al. Oral spindle cell lipoma in a cellular mass of spindle cells with a small number of mature rare location: a differential diagnosis. Am J Case Rep 2015;16:844–848 adipocytes. Spindle cell lipoma usually occurs in the subcutaneous 4. Kaku N, Kashima K, Daa T, et al. Multiple spindle cell lipomas of the tissue of the posterior neck, shoulder, and back, but it has also been tongue: a report of a case. APMIS 2003;111:581–585 described in other sites, including the spermatic cord, hypopharynx, 5. Sachdeva MP,Goldblum JR, Rubin BP,et al. Low-fat and fat-free pleomorfic parotid gland, vulva, limbs, and arms.10 However, intraoral SCLs lipomas: a diagnostic challenge. Am J Dermatopathol 2009;31:423–426 are rare. In fact, after a careful review of the literature (PubMed, 6. Chen BJ, Marin˜o-Enrı´quez A, Fletcher CDM, et al. Loss of retinoblastoma Cross-Ref), we found only 49 patients with oral SCL published in protein expression in spindle cell/pleomorphic lipomas and the English-language literature. cytogenetically related tumors: an immunohistochemical study with The histopathological differential diagnosis of oral SCL show- diagnostic implications. Am J Surg Pathol 2012;36:1119–1128 7. Zelger BW, Zelger BG, Plo¨rer A, et al. Dermal spindle cell lipoma: ing myxoid changes should include fibrous hyperplasia with plexiform and nodular variants. Histopathology 1995;27:533–540 myxoid stromal change and/or fatty metaplasia, oral focal muci- 8. Khashper A, Zheng J, Nahal A, et al. Imaging characteristics of spindle nosis, nerve sheath myxoma, myxoid neurothekeoma, myxoid cell lipoma and its variants. Skeletal Radiol 2014;43:591–597 neurofibroma/schwannoma, and eventually, soft-tissue myxoma. 9. Enzinger FM, Harvey DA. Spindle cell lipoma. Cancer 1975;36:1852–1859 If plexiform pattern is present, plexiform neurofibroma/schwan- 10. Enzinger FM, Weiss SW. Benign lipomatous tumor. In: Enzinger FM, noma, cellular neurothekeoma, and plexiform fibrohistiocytic Weiss SW, eds. Soft Tissue Tumors. 5th ed St Louis, MO: Mosby; tumor should be also considered. The clinicopathological features 2008: 431–452 and immunohistochemical findings of the current patient were 11. Darling M, Thompson I, Schneider J. Spindle cell lipoma of the alveolar sufficiently distinctive and allow to distinguish from other lesions mucosa: a case report. Oral Surg Oral Med Oral Pathol Oral Radiol Endond 2002;93:171–173 previously mentioned. In fact, our patient showed a prominent 12. Billings SD, Folpe AL. Diagnostically challenging spindle cell lipomas: myxoid stroma and, interestingly, a plexiform pattern, strongly a report of 34 ‘‘low-fat’’ and ‘‘fat-free’’ variants. Am J Dermatopathol immunoreative for CD34, whereas only adipocytes were S100 2007;29:437–442 6 positive. Moreover, loss of pRb expression was observed. To the 13. Vecchio A, Amico P, Caltabiano R, et al. Spindle cell/pleomorfic lipoma best of our knowledge, this is the first oral SCL with these of the oral cavity. J Craniofac Surg 2009;20:1992–1994 distinctive features, and it seems to represent the oral counterpart of dermal SCL, plexiform variant.7 Microscopically, SCL is variably composed of mature fat, citologically bland spindled cells, ropey collagen, myxoid matrix, and vessels, some of them with perivascular hyalinization. If adipocytes are numerous, the diagnosis is relatively straightfor- The Effect of Carnitine on ward. However, there are SCL variants which can cause diag- nostic difficulties. These variants include pseudoangiomatous, Peripheral Nerve Regeneration 11,12 vascular, fibrous, plexiform, and composite SCL. Notably, in Kemal Karaca, MD and Fevzi Solmaz, MDy some SCL patients, fat is absent or present in small amounts, which does not seem to be well recognized among pathologists.12 Introduction: Proximal and distal axons of the nerve body are Similarly, the current patient presented scarce adipocytes (‘‘low- fat’’ variant), randomly distributed throughout the lesion, and subject to varying degrees of traumatic degeneration after an admixed with numerous mast cells. Moreover, variable wiry incision. The histologic structure of rat peripheral nerves cannot to ropey collagen and focal perivascular hyalinization were be distinguished from the human. Studies on systemic carnitine evidenced. treatment following peripheral nerve injury and its positive results The SCL also must be distinguished from liposarcomas with a are available in the literature. There are no reported results of local predominantly spindle cell pattern such as well-differentiated administration. 10 sclerosing liposarcoma or myxoid liposarcoma. In fact, liposar- Methods: The authors used 50 rats. A total of 5 groups were created coma merits special mention, in that it is the most easily mistaken by randomly assigning the rats. In the first study group, the nerve diagnosis for SCL. The distinction from lipoma-like and myxoid was repaired following the incision. NaCl was locally administered liposarcomas is based on superficial location, clear demarcation, to the repair region. In the second study group, the nerve was uniformity of spindle cells with bland nuclei, and the absence of classic lipoblasts and mitotic figures.4 All these features were present in our patient. From the Department of Plastic and Reconstructive Surgery; and In summary, ‘‘low-fat’’/plexiform variant of SCL with prominent yDepartment of Otorhinolaryngology, Bursa Yuksek Ihtisas Training myxoid changes is an uncommon variant of lipoma, which can be and Research Hospital, Bursa, Turkey. misdiagnosed for other entities, predominantly composed of spindle Received April 1, 2016. cells with a myxoid stroma. From a treatment and prognosis standpoint, Accepted for publication October 8, 2016. it is especially important to recognize ‘‘low-fat’’/plexiform SCL, and Address correspondence and reprint requests to Fevzi Solmaz, MD, Depart- eventually differentiate it from malignant soft tissue myxomatous ment of Otorhinolaryngology, Bursa Yuksek Ihtisas Training and tumors, especially those of low grade.13 Spindle cell lipoma needs Research Hospital, 16800 Yildirim, Bursa, Turkey; only a local excision and no recurrence or alteration has been E-mail: [email protected] 1 The authors report no conflicts of interest. described. The diagnosis is based in the identification of characteristic Copyright # 2016 by Mutaz B. Habal, MD histopathological features, supported by immunohistochemistry ISSN: 1049-2275 5 (strong CD34 positivity), in conjunction with benign clinical features. DOI: 10.1097/SCS.0000000000003353 e160 # 2017 Mutaz B. Habal, MD Copyright © 2017 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.