Histopathology 2015, 66, 430–437. DOI: 10.1111/his.12548
Spindle cell/pleomorphic lipomas of the face: an under-recognized diagnosis Alison Cheah, Steven Billings, John Goldblum, Jason Hornick,1 Nasir Uddin2 & Brian Rubin Robert J. Tomsich Pathology and Laboratory Medicine Institute, Cleveland Clinic, Cleveland, OH, USA, 1Department of Pathology, Brigham and Women’s Hospital, Boston, MA, USA, and 2Department of Pathology and Microbiology, Aga Khan University Hospital, Karachi, Pakistan Date of submission 1 August 2014 Accepted for publication 10 September 2014 Published online Article Accepted 15 September 2014
Cheah A L, Billings S D, Goldblum J R, Hornick J L, Uddin N, Rubin B P (2015) Histopathology 66, 430–437. DOI: 10.1111/his.12548
Spindle cell/pleomorphic lipomas of the face: an under-recognized diagnosis Aims: Rarely, spindle cell/pleomorphic lipomas arise on the face where they present diagnostic difficulties. The aim of our study was to describe the clinical, histological and immunohistochemical features of a series of spindle cell/pleomorphic lipomas of the face. Methods and results: Thirty-three cases of spindle cell/ pleomorphic lipoma of the face were studied. Patient characteristics were 25 male:8 female, ranging from 33 to 91 years of age (mean 60). The most common sites were nose (nine), cheek (eight), forehead (eight), chin (three), anterior scalp (three), lip (two) and ear (two). The mean tumour size was 1.9 cm. An unusual histological feature was the involvement of skeletal
muscle, which was seen in 12 cases (36%). Otherwise, the cases exemplified the entire histological spectrum of spindle cell lipoma, including purely dermal and subcutaneous cases. By immunohistochemistry, they were uniformly positive for CD34 (26 of 26 cases), positive for oestrogen receptor in five of 21 cases and negative for desmin in all cases (none of 20 positive). Retinoblastoma (Rb) expression was lost in 18 of 19 cases. Conclusions: Due to an unusual anatomical location and frequent infiltration of skeletal muscle, spindle cell/pleomorphic lipoma of the face can be a difficult diagnosis. Increased awareness of its clinicopathological features should allow accurate classification.
Keywords: diagnosis, face, pleomorphic lipoma, spindle cell lipoma
Introduction Spindle cell and pleomorphic lipomas represent a histological spectrum of benign lipomatous tumours that occur predominantly in the posterior neck and upper back of middle-aged to elderly men.1,2 However, up to 20% of spindle cell/pleomorphic lipomas occur outside this characteristic location.2 Rarely, they can present on the face. Based on our consultation experience, it is apparent that many pathologists do not consider the diagnosis of spindle cell/pleomorphic lipoma in the differential diagnosis of spindle cell neoplasms when they arise on the face. Factors contributing to
Address for correspondence: B Rubin, Cleveland Clinic, Department of Pathology, L25, 9500 Euclid Avenue, Cleveland, OH 44195, USA. e-mail: [email protected] © 2014 John Wiley & Sons Ltd.
diagnostic uncertainty in this anatomic location include the variable morphological appearance of spindle cell/pleomorphic lipomas,3 frequent skeletal muscle involvement and the limited nature of biopsy specimens from this anatomical location. In this study, we describe the clinicopathological features of 33 spindle cell/pleomorphic lipomas, with particular focus on those tumours presenting on the face in order to bring attention to this problematic diagnosis.
Materials and methods Thirty-three cases coded as spindle cell/plemorphic lipoma involving the face, including anterior scalp and ear, from 2000 to 2014 were retrieved from Cleveland Clinic archives and consultation files with institutional review board approval (study 06-977;
Spindle cell/pleomorphic lipomas of the face
approved 15 January 2014). Four-lm haematoxylin and eosin-stained sections were examined and representative unstained slides and/or paraffin-embedded tissue blocks were available for immunohistochemical study in 26 cases. Immunohistochemistry was performed using commercially available antibodies to the following antigens: CD34 (QBEnd/10, prediluted; Cell Marque, Rocklin, CA, USA), desmin (D33, 1:10; Dako, Carpinteria, CA, USA), oestrogen receptor (SP1, prediluted; Ventana, Tuscon, AZ, USA) and RB1 (G3-245, 1:100; BD Pharmingen, Franklin Lakes, NJ, USA). Staining was scored as: 0 (no staining), 1+ (1–25%), 2+ (26–50%) and 3+ (>50%). Intensity was scored as weak, moderate or strong. The clinical data were reviewed and, where available, follow-up information was obtained from the electronic medical record or referring pathologist.
Results CLINICAL FINDINGS
The clinical findings are summarized in Table 1. Twenty-five patients were male and eight were female, with an age range of 33–91 years (mean 60 years). Twenty-one tumours were subcutaneous, including 18 males and three females. The 10 intradermal spindle cell lipomas were represented equally among males and females. Two tumours that were both subcutaneous and dermal arose in males. The most common sites were nose (nine), cheek (eight) and forehead (six, including two on the glabella), followed by chin (three), anterior scalp (three), lip (two) and ear (two). One patient had two synchronous tumours that occurred on bilateral nasal ala. Dermal spindle cell lipomas arose most commonly on the nose (six), followed by the lip (two). The most common clinical diagnosis was lipoma (seven) and cyst (five). In the remaining cases, the clinical impression was pilomatricoma (one), keloid (one), granulomatous rosacea (one), ‘rule out melanoma’ (one) or not specified (18). The submitting pathologist’s diagnoses were specified in 10 of 22 consultation cases and were: nerve sheath tumour (two), lipoma (one), spindle cell lipoma (three), solitary fibrous tumour (one), superficial angiomyxoma (one), fibromyxoid neoplasm (one) and hamartoma (one). Surgical margins could be evaluated in 26 cases. Twenty-five were excised with a positive margin and one case was excised with close margins (1 mm). Biopsy material (shave and incisional biopsies) constituted the remainder. Followup information was available for eight patients (3 months–8.3 years); no tumours recurred. © 2014 John Wiley & Sons Ltd, Histopathology, 66, 430–437.
431
HISTOPATHOLOGICAL FINDINGS
Mean tumour size was 1.9 cm (range 0.5–5.5 cm). The morphology of dermal and subcutaneous tumours was similar. Of 21 cases with an evaluable border, nine were circumscribed and 12 were infiltrative, either focally into skeletal muscle (five cases) or extensively (seven cases). Tumours with frankly infiltrative borders showed involvement of skeletal muscle only (three cases), dermal collagen only (one case), surrounding adnexal structures (two cases) or all three of these components (one case) (Figure 1). The proportion of adipose tissue was variable, and ranged from 0 to 95%. Notably, 15 of 33 cases contained a small or inconspicuous component of fat (so-called ‘low-fat’ or ‘fat-free’ variants, comprising
Spindle cell/pleomorphic lipomas of the face: an under-recognized diagnosis Alison Cheah, Steven Billings, John Goldblum, Jason Hornick,1 Nasir Uddin2 & Brian Rubin Robert J. Tomsich Pathology and Laboratory Medicine Institute, Cleveland Clinic, Cleveland, OH, USA, 1Department of Pathology, Brigham and Women’s Hospital, Boston, MA, USA, and 2Department of Pathology and Microbiology, Aga Khan University Hospital, Karachi, Pakistan Date of submission 1 August 2014 Accepted for publication 10 September 2014 Published online Article Accepted 15 September 2014
Cheah A L, Billings S D, Goldblum J R, Hornick J L, Uddin N, Rubin B P (2015) Histopathology 66, 430–437. DOI: 10.1111/his.12548
Spindle cell/pleomorphic lipomas of the face: an under-recognized diagnosis Aims: Rarely, spindle cell/pleomorphic lipomas arise on the face where they present diagnostic difficulties. The aim of our study was to describe the clinical, histological and immunohistochemical features of a series of spindle cell/pleomorphic lipomas of the face. Methods and results: Thirty-three cases of spindle cell/ pleomorphic lipoma of the face were studied. Patient characteristics were 25 male:8 female, ranging from 33 to 91 years of age (mean 60). The most common sites were nose (nine), cheek (eight), forehead (eight), chin (three), anterior scalp (three), lip (two) and ear (two). The mean tumour size was 1.9 cm. An unusual histological feature was the involvement of skeletal
muscle, which was seen in 12 cases (36%). Otherwise, the cases exemplified the entire histological spectrum of spindle cell lipoma, including purely dermal and subcutaneous cases. By immunohistochemistry, they were uniformly positive for CD34 (26 of 26 cases), positive for oestrogen receptor in five of 21 cases and negative for desmin in all cases (none of 20 positive). Retinoblastoma (Rb) expression was lost in 18 of 19 cases. Conclusions: Due to an unusual anatomical location and frequent infiltration of skeletal muscle, spindle cell/pleomorphic lipoma of the face can be a difficult diagnosis. Increased awareness of its clinicopathological features should allow accurate classification.
Keywords: diagnosis, face, pleomorphic lipoma, spindle cell lipoma
Introduction Spindle cell and pleomorphic lipomas represent a histological spectrum of benign lipomatous tumours that occur predominantly in the posterior neck and upper back of middle-aged to elderly men.1,2 However, up to 20% of spindle cell/pleomorphic lipomas occur outside this characteristic location.2 Rarely, they can present on the face. Based on our consultation experience, it is apparent that many pathologists do not consider the diagnosis of spindle cell/pleomorphic lipoma in the differential diagnosis of spindle cell neoplasms when they arise on the face. Factors contributing to
Address for correspondence: B Rubin, Cleveland Clinic, Department of Pathology, L25, 9500 Euclid Avenue, Cleveland, OH 44195, USA. e-mail: [email protected] © 2014 John Wiley & Sons Ltd.
diagnostic uncertainty in this anatomic location include the variable morphological appearance of spindle cell/pleomorphic lipomas,3 frequent skeletal muscle involvement and the limited nature of biopsy specimens from this anatomical location. In this study, we describe the clinicopathological features of 33 spindle cell/pleomorphic lipomas, with particular focus on those tumours presenting on the face in order to bring attention to this problematic diagnosis.
Materials and methods Thirty-three cases coded as spindle cell/plemorphic lipoma involving the face, including anterior scalp and ear, from 2000 to 2014 were retrieved from Cleveland Clinic archives and consultation files with institutional review board approval (study 06-977;
Spindle cell/pleomorphic lipomas of the face
approved 15 January 2014). Four-lm haematoxylin and eosin-stained sections were examined and representative unstained slides and/or paraffin-embedded tissue blocks were available for immunohistochemical study in 26 cases. Immunohistochemistry was performed using commercially available antibodies to the following antigens: CD34 (QBEnd/10, prediluted; Cell Marque, Rocklin, CA, USA), desmin (D33, 1:10; Dako, Carpinteria, CA, USA), oestrogen receptor (SP1, prediluted; Ventana, Tuscon, AZ, USA) and RB1 (G3-245, 1:100; BD Pharmingen, Franklin Lakes, NJ, USA). Staining was scored as: 0 (no staining), 1+ (1–25%), 2+ (26–50%) and 3+ (>50%). Intensity was scored as weak, moderate or strong. The clinical data were reviewed and, where available, follow-up information was obtained from the electronic medical record or referring pathologist.
Results CLINICAL FINDINGS
The clinical findings are summarized in Table 1. Twenty-five patients were male and eight were female, with an age range of 33–91 years (mean 60 years). Twenty-one tumours were subcutaneous, including 18 males and three females. The 10 intradermal spindle cell lipomas were represented equally among males and females. Two tumours that were both subcutaneous and dermal arose in males. The most common sites were nose (nine), cheek (eight) and forehead (six, including two on the glabella), followed by chin (three), anterior scalp (three), lip (two) and ear (two). One patient had two synchronous tumours that occurred on bilateral nasal ala. Dermal spindle cell lipomas arose most commonly on the nose (six), followed by the lip (two). The most common clinical diagnosis was lipoma (seven) and cyst (five). In the remaining cases, the clinical impression was pilomatricoma (one), keloid (one), granulomatous rosacea (one), ‘rule out melanoma’ (one) or not specified (18). The submitting pathologist’s diagnoses were specified in 10 of 22 consultation cases and were: nerve sheath tumour (two), lipoma (one), spindle cell lipoma (three), solitary fibrous tumour (one), superficial angiomyxoma (one), fibromyxoid neoplasm (one) and hamartoma (one). Surgical margins could be evaluated in 26 cases. Twenty-five were excised with a positive margin and one case was excised with close margins (1 mm). Biopsy material (shave and incisional biopsies) constituted the remainder. Followup information was available for eight patients (3 months–8.3 years); no tumours recurred. © 2014 John Wiley & Sons Ltd, Histopathology, 66, 430–437.
431
HISTOPATHOLOGICAL FINDINGS
Mean tumour size was 1.9 cm (range 0.5–5.5 cm). The morphology of dermal and subcutaneous tumours was similar. Of 21 cases with an evaluable border, nine were circumscribed and 12 were infiltrative, either focally into skeletal muscle (five cases) or extensively (seven cases). Tumours with frankly infiltrative borders showed involvement of skeletal muscle only (three cases), dermal collagen only (one case), surrounding adnexal structures (two cases) or all three of these components (one case) (Figure 1). The proportion of adipose tissue was variable, and ranged from 0 to 95%. Notably, 15 of 33 cases contained a small or inconspicuous component of fat (so-called ‘low-fat’ or ‘fat-free’ variants, comprising
