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Head and neck pilomatricoma: an analysis of 201 cases
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British Journal of Oral and Maxillofacial Surgery 49 (2011) 354–358
Head and neck pilomatricoma: an analysis of 201 cases N. O’Connor a , M. Patel a , T. Umar b , D.W. Macpherson a , M. Ethunandan a,∗ a
Department of Oral & Maxillofacial Surgery, St Richard’s Hospital, Western Sussex Hospital NHS Trust, Chichester, West Sussex, PO19 6SE, United Kingdom b Department of Histopathology, St Richard’s Hospital, Western Sussex Hospital NHS Trust, Chichester, West Sussex, PO19 6SE, United Kingdom Accepted 3 June 2010 Available online 1 July 2010
Abstract We report our experience with 201 pilomatricomas of the head and neck. They occurred over a wide age range (2–93 years, mean 29.5) and were most common in the first and second decades. Almost half (49%) presented in people over 40 years of age and there was no sex predilection (male:female ratio 1:1.1). The most common presentation was as a slowly enlarging, asymptomatic, subcutaneous mass, although nearly 25% were symptomatic, and 12% had a reddish blue skin discolouration. Most lesions were solitary; only 9 patients (5%) had multiple lesions. The most commonly affected sites were the cheek (23%), neck (22%), eyebrow (18%), and scalp (14%). Tumours were often mistaken for other lesions and a correct preoperative diagnosis was made in only 28% of cases. Preoperative investigations were done only occasionally and were not always helpful. All lesions were excised and excision was reported to have been incomplete in 22%. Two patients (1%) had a recurrence after incomplete excision. We highlight the condition to raise awareness among clinicians, and we support conservative excision as the most appropriate method of treatment. © 2010 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Keywords: Pilomatricoma; Pilomatrixoma: Calcifying epithelioma of Malherbe; Skin appendage tumour
Introduction Pilomatricoma is a benign follicular skin appendage tumour first described by Malherbe and Chenantais1 in 1880, and later designated calcifying epithelioma of Malherbe.2 The term pilomatrixoma proposed by Forbis and Helwig3 in 1961 was subsequently changed to the more etymologically correct pilomatricoma in 1977.4 Pilomatricomas often present as a solitary, hard, slowgrowing, subcutaneous mass, and the overlying skin may occasionally have a bluish discolouration. They can occur at any age, although most affect children and young adults. They can present in most hair-bearing parts of the body including the upper and lower extremities and trunk, but they have a predilection for the skin of the head and neck.5–9 They ∗ Corresponding author. Tel.: +44 (0) 1243 831531/831532; fax: +44 (0) 1243 831544. E-mail address: [email protected] (M. Ethunandan).
are often misdiagnosed, which can result in inappropriate management.10 Pilomatricomas are not uncommon and account for one in every 500 skin specimens submitted to pathologists,5 but to our knowledge they have been reported rarely in maxillofacial publications, and only as small case series.9 We report our experience with a series of 201 pilomatricomas of the head and neck over a 9-year period.
Patients and methods We retrospectively reviewed the case notes of all patients (n = 201) with a diagnosis of pilomatricoma who were treated at St Richard’s Hospital, Chichester, and Worthing General Hospital, Worthing between January 2000 and December 2008. The patients were identified from operating diaries and the histopathology database. Data analysed included patients’ characteristics, duration of the lesion and clinical
0266-4356/$ – see front matter © 2010 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
doi:10.1016/j.bjoms.2010.06.002
N. O’Connor et al. / British Journal of Oral and Maxillofacial Surgery 49 (2011) 354–358
355
Fig. 1. Age distribution of the lesions.
presentation, clinical diagnosis, results of preoperative investigations, treatment, histological features, and outcome.
Results Age and sex Age at the time of diagnosis ranged from 2 to 93 years (mean 29.5). The tumours occurred most commonly in the first and second decades (37%) and were distributed relatively evenly among the other age groups, with a suggestion of a second peak in the fifth and seventh decades (Fig. 1). Male to female ratio was 1:1.1.
Preoperative diagnosis Various diagnoses were made after clinical examination: pilomatricoma (56); sebaceous cyst (70); epidermoid cyst (38); cyst (23); basal cell or squamous cell carcinoma (10); vascular lesion (4); and lymph node (3). In a few cases multiple diagnoses were considered, and in 16 the original diagnosis was changed to pilomatricoma at operation. Imaging was done in five cases; ultrasound was requested in four, and computed tomography (CT) in one. The results of the scans were inconclusive in two cases (ultrasound and CT), and in the others the lesion was reported as a complicated skin appendage lesion, a calcified lesion, and a sebaceous cyst.
Clinical presentation The most common clinical presentation was of a slowly enlarging, asymptomatic, subcutaneous hard mass that was often attached to the skin, which was stretched, but was freely mobile over the underlying tissues (Fig. 2). However, 46 patients had discomfort, 21 had episodes of infection or discharge, eight had lesions that grew rapidly, and seven had lesions that fluctuated in size. The duration of the lesions ranged from 6 weeks to 30 years, but most had been present for a “few months” before the patient sought treatment. The overlying skin had a bluish red discolouration in 24 patients. Lesions were seen throughout the head and neck (Fig. 3), and nine patients (5%) had more than one. Of these, two patients had them at the same time, and seven had them at different times (1–4 years).
Fig. 2. Clinical image of lesion in the eyebrow.
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N. O’Connor et al. / British Journal of Oral and Maxillofacial Surgery 49 (2011) 354–358
Fig. 5. Photomicrograph showing the central zone of eosinophilic shadow cells (thick arrow) and a peripheral rim of basaloid cells (thin arrow) (haematoxylin and eosin, original magnification ×4).
Fig. 3. Sites and numbers of lesions.
Histology Two patients had fine needle aspiration (FNA) and one had punch biopsy. Pilomatricoma was diagnosed in two cases (FNA and punch), and diagnosis was inconclusive in the other. Treatment and outcome The lesions were usually excised with minimal margins and were easily dissected from the surrounding tissues (Fig. 4). In 71 patients excision was complete, in 45 margins were incomplete, and in 85 no information was available. Follow up ranged from 1 months to 18 months (mean 1.6). Two patients had recurrences that were diagnosed four and 10 months after the initial excision. In both the tumour had not been excised completely in the first instance. After re-excision there were no further recurrences at follow up of 12 and 14 months.
Fig. 4. Operative view showing a well defined subcutaneous mass with calcification.
Histological examination confirmed typical pilomatricoma in almost all cases. The tumours were well circumscribed with a biphasic cellular composition consisting of distinct central and peripheral components (Fig. 5). The peripheral zone consisted of small, uniform, darkly staining basaloid cells of hair matrix origin. The central part was formed by remnants of cells that had lost their nuclei, and are called “ghost or shadow” cells (Fig. 6). Most lesions had varying degrees of calcification or ossification, and in a few cases the central area was associated with secondary foreign body giant cell reaction. Three cases had additional features of central ulceration, superficial tumour budding of the basal epidermis, or squamous differentiation.
Fig. 6. Photomicrograph showing the rim of darkly staining basaloid matrix cells (thick arrow) and a central area (thin arrow) of eosinophilic “shadow” cells that have lost their nuclei (haematoxylin and eosin, original magnification ×20).
N. O’Connor et al. / British Journal of Oral and Maxillofacial Surgery 49 (2011) 354–358
Discussion Pilomatricomas often present as a gradually enlarging, asymptomatic, mobile, hard subcutaneous mass.5–9 In the more superficial lesions in our study, the overlying skin was often stretched, and calcifications could be seen as yellow or white flecks through the surface (Figs. 2 and 4). Deeper lesions often had no specific discriminating features. Twenty-two percent of our patients had discomfort, 10% had episodes of infection, and 12% of the lesions presented with discolouration of the overlying skin. Given these varying presentations it is not surprising that many lesions were misdiagnosed. The low diagnostic accuracy could also be attributed to a possible lack of awareness of the tumour by clinicians. In our series the correct preoperative clinical diagnosis was made in only 28% of cases, which is similar to those in other reports.5–8 The most common misdiagnosis was sebaceous (35%) and epidermoid (19%) cysts, which is not surprising as these lesions are much more common and can have a similar appearance. Epidermoid (sebaceous) cysts are often spherical and firm, are attached to the overlying skin, and have a punctum, whereas pilomatricomas often present as a subcutaneous mass with a hard nodular surface, and are freely mobile from the underlying tissues, although the skin attachment can occasionally be mistaken for a punctum. The “tent sign”, where stretching the skin over the mass to allow the nodular surface to become apparent, can help narrow the diagnosis.11 Although pilomatricomas occur over a wide age range they often present in children, whereas epidermoid cysts are not common in this prepubertal age group. In our series 36% presented in the first two decades. Another clue to the diagnosis was found at operation where calcifications within the mass were noted (Fig. 4). Diagnosis was changed at operation in 8% of our patients. The sites of the lesions with the cheek, eye brow, and neck being the most common, is fairly typical of those reported.5–10 It might be surprising that lesions that arise from a hair follicle are not more common in the scalp, but this could be explained by the fact that the density of hair follicles in the face is about twice that of the scalp.12 The tumours occurred most commonly in the first and second decades, which agrees with other published reports.5–8 Interestingly, almost half the lesions in our series (98/201, 49%) presented in people over 40 years of age, and this aspect, to our knowledge, has rarely been highlighted before.13 The equal distribution of the tumours among men and women in our series differs from that in other studies, which have reported a higher incidence in women.5–7 Although pilomatricomas are solitary lesions, 5% of our patients had multiple lesions. Multiple lesions are reported to occur in 2–10% of cases5–8 and are said to be more common in patients with myotonic dystrophy, sarcoidosis, Steinert disease, and Gardner syndrome, but these were not confirmed in our series. Preoperative imaging using plain radiography, ultrasound, CT, and magnetic resonance (MRI) is rarely considered in
357
the investigation of a pilomatricoma, and is often done only when the clinical diagnosis is not clear. Ultrasound is a relatively accessible, low cost, non-invasive procedure that can be done in the young without sedation or anaesthesia, and it can show the superficial location of the lesion along with calcification, which can help in the diagnosis. CT and MRI are often requested for lesions that present in the parotid and neck. In our series imaging did not consistently provide an accurate diagnosis, which is similar to the experience of other authors.6–8 FNA is often considered as part of the diagnostic investigation of a mass in the head and neck. The presence of ghost cells and basaloid cells on FNA from a subcutaneous mass is considered enough to diagnose pilomatricoma.14 In our series FNA confirmed the diagnosis in one of the two cases in which it was done. The treatment of choice for pilomatricoma remains complete excision,5–9 although some authors have advocated incision and curettage with similar results.15 The lesion is often excised with minimal margins, given the cosmetically sensitive areas in the head and neck, and its misdiagnosis as various other benign lesions. Our findings suggest that conservative excision is the treatment of choice, but every effort should be made to excise the lesions completely. We do not follow up patients for a prolonged period, but educate them to check themselves and report back if they are concerned about recurrence. Malignant transformation (pilomatrix carcinoma) is very rare, and we know of fewer than 80 cases reported worldwide. It is most common in the head and neck and has a male predominance and a predilection for the elderly.16 No lesions in our series were malignant.
References 1. Malherbe A, Chenantais J. Note sur l’epithelioma calcifie des glandes sebacees. Prog Med (Paris) 1880;8:826–8. 2. Geiser JD. L’epithelioma calcifie de Malherbe (Malherbe’s calcified epithelioma). Ann Dermatol Syphiligr (Paris) 1959;86:383–403. 3. Forbis Jr R, Helwig EB. Pilomatrixoma (calcifying epithelioma). Arch Dermatol 1961;83:606–18. 4. Arnold Jr HL. Letter: pilomatrixoma. Arch Dermatol 1977;113:1303. 5. Julian CG, Bowers PW. A clinical review of 209 pilomatricomas. J Am Acad Dermatol 1998;39:191–5. 6. Pirouzmanesh A, Reinisch JF, Gonzales-Gomez I, Smith EM, Meara JG. Pilomatrixoma: a review of 346 cases. Plast Reconstr Surg 2003;112:1784–9. 7. Danielson-Cohen A, Lin SJ, Hughes CA, An YH, Maddalozzo J. Head and neck pilomatrixoma in children. Arch Otolaryngol Head Neck Surg 2001;127:1481–3. 8. Lan MY, Lan MC, Ho CY, Li WY, Lin CZ. Pilomatricoma of the head and neck: a retrospective review of 179 cases. Arch Otolaryngol Head Neck Surg 2003;129:1327–30. 9. YoshimuraY, Obara S, Mikami T, Matsuda S. Calcifying epithelioma (pilomatrixoma) of the head and neck: analysis of 37 cases. Br J Oral Maxillofac Surg 1997;35:429–32. 10. Kumaran N, Azmy A, Carachi R, Raine PA, Macfarlane JH, Howatson AG. Pilomatrixoma—accuracy of clinical diagnosis. J Pediatr Surg 2006;41:1755–8.
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N. O’Connor et al. / British Journal of Oral and Maxillofacial Surgery 49 (2011) 354–358
11. Graham JL, Merwin CF. The tent sign of pilomatricoma. Cutis 1978;22:577–80. 12. Noguchi H, Hayashibara T, Ono T. A statistical study of calcifying epithelioma, focusing on the sites of origin. J Dermatol 1995;22: 24–7. 13. Kaddu S, Soyer HP, Cerroni L, Salmhofer W, Hödl S. Clinical and histopathologic spectrum of pilomaticomas in adults. Int J Dermatol 1994;33:705–8.
14. Wang J, Cobb CJ, Martin SE, Venegas R, Wu N, Greaves TS. Pilomatrixoma: clinicopathologic study of 51 cases with emphasis on cytologic features. Diagn Cytopathol 2002;27:167–72. 15. Morales A, McGoey J. Pilomatricoma: treatment by incision and curettement. J Am Acad Dermatol 1980;2:44–6. 16. Hardisson D, Linares MD, Cuevas-Santos J, Contreras F. Pilomatrix carcinoma: a clinicopathologic study of six cases and review of the literature. Am J Dermatopathol 2001;23:394–401.
British Journal of Oral and Maxillofacial Surgery 49 (2011) 354–358
Head and neck pilomatricoma: an analysis of 201 cases N. O’Connor a , M. Patel a , T. Umar b , D.W. Macpherson a , M. Ethunandan a,∗ a
Department of Oral & Maxillofacial Surgery, St Richard’s Hospital, Western Sussex Hospital NHS Trust, Chichester, West Sussex, PO19 6SE, United Kingdom b Department of Histopathology, St Richard’s Hospital, Western Sussex Hospital NHS Trust, Chichester, West Sussex, PO19 6SE, United Kingdom Accepted 3 June 2010 Available online 1 July 2010
Abstract We report our experience with 201 pilomatricomas of the head and neck. They occurred over a wide age range (2–93 years, mean 29.5) and were most common in the first and second decades. Almost half (49%) presented in people over 40 years of age and there was no sex predilection (male:female ratio 1:1.1). The most common presentation was as a slowly enlarging, asymptomatic, subcutaneous mass, although nearly 25% were symptomatic, and 12% had a reddish blue skin discolouration. Most lesions were solitary; only 9 patients (5%) had multiple lesions. The most commonly affected sites were the cheek (23%), neck (22%), eyebrow (18%), and scalp (14%). Tumours were often mistaken for other lesions and a correct preoperative diagnosis was made in only 28% of cases. Preoperative investigations were done only occasionally and were not always helpful. All lesions were excised and excision was reported to have been incomplete in 22%. Two patients (1%) had a recurrence after incomplete excision. We highlight the condition to raise awareness among clinicians, and we support conservative excision as the most appropriate method of treatment. © 2010 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Keywords: Pilomatricoma; Pilomatrixoma: Calcifying epithelioma of Malherbe; Skin appendage tumour
Introduction Pilomatricoma is a benign follicular skin appendage tumour first described by Malherbe and Chenantais1 in 1880, and later designated calcifying epithelioma of Malherbe.2 The term pilomatrixoma proposed by Forbis and Helwig3 in 1961 was subsequently changed to the more etymologically correct pilomatricoma in 1977.4 Pilomatricomas often present as a solitary, hard, slowgrowing, subcutaneous mass, and the overlying skin may occasionally have a bluish discolouration. They can occur at any age, although most affect children and young adults. They can present in most hair-bearing parts of the body including the upper and lower extremities and trunk, but they have a predilection for the skin of the head and neck.5–9 They ∗ Corresponding author. Tel.: +44 (0) 1243 831531/831532; fax: +44 (0) 1243 831544. E-mail address: [email protected] (M. Ethunandan).
are often misdiagnosed, which can result in inappropriate management.10 Pilomatricomas are not uncommon and account for one in every 500 skin specimens submitted to pathologists,5 but to our knowledge they have been reported rarely in maxillofacial publications, and only as small case series.9 We report our experience with a series of 201 pilomatricomas of the head and neck over a 9-year period.
Patients and methods We retrospectively reviewed the case notes of all patients (n = 201) with a diagnosis of pilomatricoma who were treated at St Richard’s Hospital, Chichester, and Worthing General Hospital, Worthing between January 2000 and December 2008. The patients were identified from operating diaries and the histopathology database. Data analysed included patients’ characteristics, duration of the lesion and clinical
0266-4356/$ – see front matter © 2010 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
doi:10.1016/j.bjoms.2010.06.002
N. O’Connor et al. / British Journal of Oral and Maxillofacial Surgery 49 (2011) 354–358
355
Fig. 1. Age distribution of the lesions.
presentation, clinical diagnosis, results of preoperative investigations, treatment, histological features, and outcome.
Results Age and sex Age at the time of diagnosis ranged from 2 to 93 years (mean 29.5). The tumours occurred most commonly in the first and second decades (37%) and were distributed relatively evenly among the other age groups, with a suggestion of a second peak in the fifth and seventh decades (Fig. 1). Male to female ratio was 1:1.1.
Preoperative diagnosis Various diagnoses were made after clinical examination: pilomatricoma (56); sebaceous cyst (70); epidermoid cyst (38); cyst (23); basal cell or squamous cell carcinoma (10); vascular lesion (4); and lymph node (3). In a few cases multiple diagnoses were considered, and in 16 the original diagnosis was changed to pilomatricoma at operation. Imaging was done in five cases; ultrasound was requested in four, and computed tomography (CT) in one. The results of the scans were inconclusive in two cases (ultrasound and CT), and in the others the lesion was reported as a complicated skin appendage lesion, a calcified lesion, and a sebaceous cyst.
Clinical presentation The most common clinical presentation was of a slowly enlarging, asymptomatic, subcutaneous hard mass that was often attached to the skin, which was stretched, but was freely mobile over the underlying tissues (Fig. 2). However, 46 patients had discomfort, 21 had episodes of infection or discharge, eight had lesions that grew rapidly, and seven had lesions that fluctuated in size. The duration of the lesions ranged from 6 weeks to 30 years, but most had been present for a “few months” before the patient sought treatment. The overlying skin had a bluish red discolouration in 24 patients. Lesions were seen throughout the head and neck (Fig. 3), and nine patients (5%) had more than one. Of these, two patients had them at the same time, and seven had them at different times (1–4 years).
Fig. 2. Clinical image of lesion in the eyebrow.
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N. O’Connor et al. / British Journal of Oral and Maxillofacial Surgery 49 (2011) 354–358
Fig. 5. Photomicrograph showing the central zone of eosinophilic shadow cells (thick arrow) and a peripheral rim of basaloid cells (thin arrow) (haematoxylin and eosin, original magnification ×4).
Fig. 3. Sites and numbers of lesions.
Histology Two patients had fine needle aspiration (FNA) and one had punch biopsy. Pilomatricoma was diagnosed in two cases (FNA and punch), and diagnosis was inconclusive in the other. Treatment and outcome The lesions were usually excised with minimal margins and were easily dissected from the surrounding tissues (Fig. 4). In 71 patients excision was complete, in 45 margins were incomplete, and in 85 no information was available. Follow up ranged from 1 months to 18 months (mean 1.6). Two patients had recurrences that were diagnosed four and 10 months after the initial excision. In both the tumour had not been excised completely in the first instance. After re-excision there were no further recurrences at follow up of 12 and 14 months.
Fig. 4. Operative view showing a well defined subcutaneous mass with calcification.
Histological examination confirmed typical pilomatricoma in almost all cases. The tumours were well circumscribed with a biphasic cellular composition consisting of distinct central and peripheral components (Fig. 5). The peripheral zone consisted of small, uniform, darkly staining basaloid cells of hair matrix origin. The central part was formed by remnants of cells that had lost their nuclei, and are called “ghost or shadow” cells (Fig. 6). Most lesions had varying degrees of calcification or ossification, and in a few cases the central area was associated with secondary foreign body giant cell reaction. Three cases had additional features of central ulceration, superficial tumour budding of the basal epidermis, or squamous differentiation.
Fig. 6. Photomicrograph showing the rim of darkly staining basaloid matrix cells (thick arrow) and a central area (thin arrow) of eosinophilic “shadow” cells that have lost their nuclei (haematoxylin and eosin, original magnification ×20).
N. O’Connor et al. / British Journal of Oral and Maxillofacial Surgery 49 (2011) 354–358
Discussion Pilomatricomas often present as a gradually enlarging, asymptomatic, mobile, hard subcutaneous mass.5–9 In the more superficial lesions in our study, the overlying skin was often stretched, and calcifications could be seen as yellow or white flecks through the surface (Figs. 2 and 4). Deeper lesions often had no specific discriminating features. Twenty-two percent of our patients had discomfort, 10% had episodes of infection, and 12% of the lesions presented with discolouration of the overlying skin. Given these varying presentations it is not surprising that many lesions were misdiagnosed. The low diagnostic accuracy could also be attributed to a possible lack of awareness of the tumour by clinicians. In our series the correct preoperative clinical diagnosis was made in only 28% of cases, which is similar to those in other reports.5–8 The most common misdiagnosis was sebaceous (35%) and epidermoid (19%) cysts, which is not surprising as these lesions are much more common and can have a similar appearance. Epidermoid (sebaceous) cysts are often spherical and firm, are attached to the overlying skin, and have a punctum, whereas pilomatricomas often present as a subcutaneous mass with a hard nodular surface, and are freely mobile from the underlying tissues, although the skin attachment can occasionally be mistaken for a punctum. The “tent sign”, where stretching the skin over the mass to allow the nodular surface to become apparent, can help narrow the diagnosis.11 Although pilomatricomas occur over a wide age range they often present in children, whereas epidermoid cysts are not common in this prepubertal age group. In our series 36% presented in the first two decades. Another clue to the diagnosis was found at operation where calcifications within the mass were noted (Fig. 4). Diagnosis was changed at operation in 8% of our patients. The sites of the lesions with the cheek, eye brow, and neck being the most common, is fairly typical of those reported.5–10 It might be surprising that lesions that arise from a hair follicle are not more common in the scalp, but this could be explained by the fact that the density of hair follicles in the face is about twice that of the scalp.12 The tumours occurred most commonly in the first and second decades, which agrees with other published reports.5–8 Interestingly, almost half the lesions in our series (98/201, 49%) presented in people over 40 years of age, and this aspect, to our knowledge, has rarely been highlighted before.13 The equal distribution of the tumours among men and women in our series differs from that in other studies, which have reported a higher incidence in women.5–7 Although pilomatricomas are solitary lesions, 5% of our patients had multiple lesions. Multiple lesions are reported to occur in 2–10% of cases5–8 and are said to be more common in patients with myotonic dystrophy, sarcoidosis, Steinert disease, and Gardner syndrome, but these were not confirmed in our series. Preoperative imaging using plain radiography, ultrasound, CT, and magnetic resonance (MRI) is rarely considered in
357
the investigation of a pilomatricoma, and is often done only when the clinical diagnosis is not clear. Ultrasound is a relatively accessible, low cost, non-invasive procedure that can be done in the young without sedation or anaesthesia, and it can show the superficial location of the lesion along with calcification, which can help in the diagnosis. CT and MRI are often requested for lesions that present in the parotid and neck. In our series imaging did not consistently provide an accurate diagnosis, which is similar to the experience of other authors.6–8 FNA is often considered as part of the diagnostic investigation of a mass in the head and neck. The presence of ghost cells and basaloid cells on FNA from a subcutaneous mass is considered enough to diagnose pilomatricoma.14 In our series FNA confirmed the diagnosis in one of the two cases in which it was done. The treatment of choice for pilomatricoma remains complete excision,5–9 although some authors have advocated incision and curettage with similar results.15 The lesion is often excised with minimal margins, given the cosmetically sensitive areas in the head and neck, and its misdiagnosis as various other benign lesions. Our findings suggest that conservative excision is the treatment of choice, but every effort should be made to excise the lesions completely. We do not follow up patients for a prolonged period, but educate them to check themselves and report back if they are concerned about recurrence. Malignant transformation (pilomatrix carcinoma) is very rare, and we know of fewer than 80 cases reported worldwide. It is most common in the head and neck and has a male predominance and a predilection for the elderly.16 No lesions in our series were malignant.
References 1. Malherbe A, Chenantais J. Note sur l’epithelioma calcifie des glandes sebacees. Prog Med (Paris) 1880;8:826–8. 2. Geiser JD. L’epithelioma calcifie de Malherbe (Malherbe’s calcified epithelioma). Ann Dermatol Syphiligr (Paris) 1959;86:383–403. 3. Forbis Jr R, Helwig EB. Pilomatrixoma (calcifying epithelioma). Arch Dermatol 1961;83:606–18. 4. Arnold Jr HL. Letter: pilomatrixoma. Arch Dermatol 1977;113:1303. 5. Julian CG, Bowers PW. A clinical review of 209 pilomatricomas. J Am Acad Dermatol 1998;39:191–5. 6. Pirouzmanesh A, Reinisch JF, Gonzales-Gomez I, Smith EM, Meara JG. Pilomatrixoma: a review of 346 cases. Plast Reconstr Surg 2003;112:1784–9. 7. Danielson-Cohen A, Lin SJ, Hughes CA, An YH, Maddalozzo J. Head and neck pilomatrixoma in children. Arch Otolaryngol Head Neck Surg 2001;127:1481–3. 8. Lan MY, Lan MC, Ho CY, Li WY, Lin CZ. Pilomatricoma of the head and neck: a retrospective review of 179 cases. Arch Otolaryngol Head Neck Surg 2003;129:1327–30. 9. YoshimuraY, Obara S, Mikami T, Matsuda S. Calcifying epithelioma (pilomatrixoma) of the head and neck: analysis of 37 cases. Br J Oral Maxillofac Surg 1997;35:429–32. 10. Kumaran N, Azmy A, Carachi R, Raine PA, Macfarlane JH, Howatson AG. Pilomatrixoma—accuracy of clinical diagnosis. J Pediatr Surg 2006;41:1755–8.
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N. O’Connor et al. / British Journal of Oral and Maxillofacial Surgery 49 (2011) 354–358
11. Graham JL, Merwin CF. The tent sign of pilomatricoma. Cutis 1978;22:577–80. 12. Noguchi H, Hayashibara T, Ono T. A statistical study of calcifying epithelioma, focusing on the sites of origin. J Dermatol 1995;22: 24–7. 13. Kaddu S, Soyer HP, Cerroni L, Salmhofer W, Hödl S. Clinical and histopathologic spectrum of pilomaticomas in adults. Int J Dermatol 1994;33:705–8.
14. Wang J, Cobb CJ, Martin SE, Venegas R, Wu N, Greaves TS. Pilomatrixoma: clinicopathologic study of 51 cases with emphasis on cytologic features. Diagn Cytopathol 2002;27:167–72. 15. Morales A, McGoey J. Pilomatricoma: treatment by incision and curettement. J Am Acad Dermatol 1980;2:44–6. 16. Hardisson D, Linares MD, Cuevas-Santos J, Contreras F. Pilomatrix carcinoma: a clinicopathologic study of six cases and review of the literature. Am J Dermatopathol 2001;23:394–401.