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Proliferating pilomatricoma: a subset of pilomatricoma
Journal of Plastic, Reconstructive & Aesthetic Surgery (2008) 61, 811e814
CASE REPORT
Proliferating pilomatricoma: a subset of pilomatricoma Atsuko Sakai a,*, Yu Maruyama b, Akiteru Hayashi a,c a
Department of Plastic and Reconstructive Surgery, Toho University Ohashi Hospital, Tokyo, Japan Plastic and Reconstructive Surgery, Toho University Hospital, Tokyo, Japan c Plastic and Reconstructive Surgery, Toho University Sakura Hospital, Chiba, Japan b
Received 26 June 2006; accepted 7 February 2007
KEYWORDS Proliferating pilomatricoma; Hair matrix differentiation
Summary Proliferating pilomatricoma is a histopathological entity that was proposed by Kaddu et al. in 1997. Proliferating pilomatricoma represents a distinctive histopathological entity; it should be differentiated from other benign and malignant neoplasms with features of hair matrix differentiation. Kaddu reported that an incompletely excised proliferating pilomatricoma may have a greater potential for local recurrence, because histopathologically it showed variable nuclear atypia and several mitotic figures. We report two patients with proliferating pilomatricoma and describe their clinical and pathological features. ª 2008 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.
Proliferating pilomatricoma is a histopathological entity that was proposed by Kaddu et al. in 1997.1 It can be regarded as the conceptual framework for benign, proliferating, or giant adnexal neoplasms that histopathologically mimic their malignant counterparts. However, to date, very few cases of proliferating pilomatricoma have been described in the literature. We report two patients with proliferating pilomatricoma and describe their clinical and pathological features.
* Corresponding author. Address: Plastic and Reconstructive Surgery, Toho University Ohashi Hospital, 2-17-6 Ohashi, Meguro-ku, Tokyo 153-8515, Japan. Tel.: þ81 03 3468 1251. E-mail address: [email protected] (A. Sakai).
Case reports Case 1 A 60-year-old female presented with a 2-month history of a rapidly enlarging mass on her right forehead. The tumour comprised a firm round mass measuring 35 25 30 mm with ulceration (Fig. 1). Computed tomographic imaging revealed a soft tissue shadow. Both T1- and T2-weighted magnetic resonance imaging scans revealed isointensity (Fig. 2). A second small tumour was observed on the right temporal region. The forehead tumour was widely excised with a 3 cm margin, including the periosteum. The small temporal tumour was excised simultaneously.
1748-6815/$ - see front matter ª 2008 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.bjps.2007.02.013
812
A. Sakai et al. Histopathologically, the frontal lesion showed a large area of basaloid cells with numerous mitotic figures. However, in contrast to malignant tumours, the basaloid lobules revealed cystic spaces filled with fibrous material, histopathology showed a well circumscribed legion composed of smoothly outlined basaloid lobules (Fig. 3). The histopathological diagnosis of the forehead tumour was proliferating pilomatricoma. On the other hand, the temporal tumour was an ordinary pilomatricoma. The patient presented no evidence of local recurrence 3 years after the excision.
Case 2 A 49-year-old female presented with a painless, rapidly enlarging mass on her posterior neck. The tumour was observed to be a dome-shaped, polypoid lesion, measuring 34 30 25 mm, with small ulceration (Fig. 4). On both X-ray and computed tomogram, a tumor on her posterior neck presented a soft tissue mass (Fig. 5). There were two other small subcutaneous tumours on her shoulder and the region just caudal to the posterior neck tumour. Her past medical history included several surgeries for removal of calcified tumours from her back and neck during childhood. The tumours were excised marginally and the wound was closed primarily. Histopathological examination of the legion on the posterior neck revealed lobular proliferation of basaloid cells in association with adjacent focal areas containing eosinophilic, cornified material with shadow cells and a larger number of mitotic figures. Scaning magnification shows a symmetrical, and the basaloid aggregations are in continuity with cornified material incorporating shadow cells (Fig. 6). The histpathological diagnosis of this lesion was Figure 1
Figure 2
Figure 3
Proliferating pilomatricoma
813
Figure 4
proliferating pilomatricoma, while the other two small tumours were pilomatricoma. The patient had no evidence of local recurrence 1 year after the excision.
Discussion In 1997 proliferating pilomatricoma was first described by Kaddu et al. as a histopathologically distinctive subset of
pilomatricoma.1 They examined retrospectively, and found cases which showed unusual architectural features histopathologically. On clinical examination, a majority of the patients were elderly individuals, the lesions were found to be painless, dome-shaped, solitary, medium- to large-sized nodules in the head and neck regions. On histopathological examination, these were mainly found to be characterised by a lobular proliferation of basaloid cells in association with adjacent focal areas containing eosinophilic, cornified material along with shadow cells. Cytomorphologically, the basaloid cells showed variable nuclear atypia and several mitotic figures, ranging from four to 15 mitotic figures per high power field (HPF).1 There are, however, no features suggestive of lymphatic or perineural involvement. Both of our patients were elderly individuals, and the lesions were located in their head and neck regions. On histopathological examination, the lesions revealed solid and cystic lobules of basaloid cells in association with small or large foci of shadow cells and a large number of mitotic figures indicating an increased number of basaloid cells. These features are in agreement with those described by Kaddu. Hence, we diagnosed the lesions observed in both cases as proliferating pilomatricomas. Both cases presented with pilomatricomas at the same time, with one patient having a further history of resection of calcified tumours. Although Kaddu did not refer to complication of pilomatricomas, complication of other calcified tumours might be one of the clinical features of proliferating pilomatricoma. A large number of patients with proliferating pilomatricoma would need to be analysed to define its clinical features. Pilomatricoma, proliferating pilomatricoma, and pilomatrical carcinoma show features of hair matrix differentiation.1e3 It is difficult to diagnose pilomatrical tumours based on the clinical features.4e7 Hence, the diagnosis needs to be confirmed with histopathological and cytomorphological examinations.1e3,8e10 Kaddu reported that an incompletely excised proliferating pilomatricoma may have a greater potential for local recurrence compared to ordinary pilomatricomas and presented an example of local recurrence in one patient. It is not presently known
Figure 5
814
A. Sakai et al.
Figure 6
whether proliferating pilomatricoma is a precursor of pilomatrical carcinoma. Therefore, all of these neoplasmas should be excised with adequate surgical margins, and careful follow-up examinations are strongly recommended in all of these patients. In conclusion, proliferating pilomatricoma represents a distinctive histopathological entity; it should be differentiated from other benign and malignant neoplasms with features of hair matrix differentiation.
References 1. Kaddu S, Soyer HP, Wolf IH, et al. Proliferating pilomatricoma. J Cutan Pathol 1997;24:228e34. 2. Elder D. Lever’s Histopathology of Skin. 8th ed. Philadelphia: Lippincott Williams & Wilkins; 1997. p. 757e9.
3. Rosai J. Ackerman’s Surgical Pathology. 8th ed. St. Louis: Mosby; 1996. p. 138. 4. Aslan G, Erdogan B, Akoz T, et al. Multiple occurrence of pilomatrixoma. Plast Reconstr Surg 1996;98:510e3. 5. Brandner MD, Bunkis J. Pilomatrixoma presenting as a parotid mass. Plast Reconstr Surg 1986;78:518e21. 6. Sasaki CT, Yue A, Enriques R. Giant calcifying epithelioma. Arch Otolaryngol 1976;102:753e5. 7. Kaddu S, Soyer HP, Cerroni L, et al. The clinical and histopathologic spectrum of pilomatricomas in adults. Int J Dermatol 1994;33:705e8. 8. Marrogi AJ, Wick MR, Dehner LP. Pilomatrical neoplasms in children and young adults. Am J Dermatopathol 1992;14:87e94. 9. Hardisson D, Linares MD, Cuevas-Santos J, et al. Pilomatrix carcinoma: a clinicopathologic study of six cases and review of the literature. Am J Dermatopathol 2001;23:394e401. 10. Mcculloch TA, Singh S, Cotton DW. Pilomatrix carcinoma and multiple pilomatrixomas. Br J Dermatol 1996;134:368e71.
CASE REPORT
Proliferating pilomatricoma: a subset of pilomatricoma Atsuko Sakai a,*, Yu Maruyama b, Akiteru Hayashi a,c a
Department of Plastic and Reconstructive Surgery, Toho University Ohashi Hospital, Tokyo, Japan Plastic and Reconstructive Surgery, Toho University Hospital, Tokyo, Japan c Plastic and Reconstructive Surgery, Toho University Sakura Hospital, Chiba, Japan b
Received 26 June 2006; accepted 7 February 2007
KEYWORDS Proliferating pilomatricoma; Hair matrix differentiation
Summary Proliferating pilomatricoma is a histopathological entity that was proposed by Kaddu et al. in 1997. Proliferating pilomatricoma represents a distinctive histopathological entity; it should be differentiated from other benign and malignant neoplasms with features of hair matrix differentiation. Kaddu reported that an incompletely excised proliferating pilomatricoma may have a greater potential for local recurrence, because histopathologically it showed variable nuclear atypia and several mitotic figures. We report two patients with proliferating pilomatricoma and describe their clinical and pathological features. ª 2008 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.
Proliferating pilomatricoma is a histopathological entity that was proposed by Kaddu et al. in 1997.1 It can be regarded as the conceptual framework for benign, proliferating, or giant adnexal neoplasms that histopathologically mimic their malignant counterparts. However, to date, very few cases of proliferating pilomatricoma have been described in the literature. We report two patients with proliferating pilomatricoma and describe their clinical and pathological features.
* Corresponding author. Address: Plastic and Reconstructive Surgery, Toho University Ohashi Hospital, 2-17-6 Ohashi, Meguro-ku, Tokyo 153-8515, Japan. Tel.: þ81 03 3468 1251. E-mail address: [email protected] (A. Sakai).
Case reports Case 1 A 60-year-old female presented with a 2-month history of a rapidly enlarging mass on her right forehead. The tumour comprised a firm round mass measuring 35 25 30 mm with ulceration (Fig. 1). Computed tomographic imaging revealed a soft tissue shadow. Both T1- and T2-weighted magnetic resonance imaging scans revealed isointensity (Fig. 2). A second small tumour was observed on the right temporal region. The forehead tumour was widely excised with a 3 cm margin, including the periosteum. The small temporal tumour was excised simultaneously.
1748-6815/$ - see front matter ª 2008 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.bjps.2007.02.013
812
A. Sakai et al. Histopathologically, the frontal lesion showed a large area of basaloid cells with numerous mitotic figures. However, in contrast to malignant tumours, the basaloid lobules revealed cystic spaces filled with fibrous material, histopathology showed a well circumscribed legion composed of smoothly outlined basaloid lobules (Fig. 3). The histopathological diagnosis of the forehead tumour was proliferating pilomatricoma. On the other hand, the temporal tumour was an ordinary pilomatricoma. The patient presented no evidence of local recurrence 3 years after the excision.
Case 2 A 49-year-old female presented with a painless, rapidly enlarging mass on her posterior neck. The tumour was observed to be a dome-shaped, polypoid lesion, measuring 34 30 25 mm, with small ulceration (Fig. 4). On both X-ray and computed tomogram, a tumor on her posterior neck presented a soft tissue mass (Fig. 5). There were two other small subcutaneous tumours on her shoulder and the region just caudal to the posterior neck tumour. Her past medical history included several surgeries for removal of calcified tumours from her back and neck during childhood. The tumours were excised marginally and the wound was closed primarily. Histopathological examination of the legion on the posterior neck revealed lobular proliferation of basaloid cells in association with adjacent focal areas containing eosinophilic, cornified material with shadow cells and a larger number of mitotic figures. Scaning magnification shows a symmetrical, and the basaloid aggregations are in continuity with cornified material incorporating shadow cells (Fig. 6). The histpathological diagnosis of this lesion was Figure 1
Figure 2
Figure 3
Proliferating pilomatricoma
813
Figure 4
proliferating pilomatricoma, while the other two small tumours were pilomatricoma. The patient had no evidence of local recurrence 1 year after the excision.
Discussion In 1997 proliferating pilomatricoma was first described by Kaddu et al. as a histopathologically distinctive subset of
pilomatricoma.1 They examined retrospectively, and found cases which showed unusual architectural features histopathologically. On clinical examination, a majority of the patients were elderly individuals, the lesions were found to be painless, dome-shaped, solitary, medium- to large-sized nodules in the head and neck regions. On histopathological examination, these were mainly found to be characterised by a lobular proliferation of basaloid cells in association with adjacent focal areas containing eosinophilic, cornified material along with shadow cells. Cytomorphologically, the basaloid cells showed variable nuclear atypia and several mitotic figures, ranging from four to 15 mitotic figures per high power field (HPF).1 There are, however, no features suggestive of lymphatic or perineural involvement. Both of our patients were elderly individuals, and the lesions were located in their head and neck regions. On histopathological examination, the lesions revealed solid and cystic lobules of basaloid cells in association with small or large foci of shadow cells and a large number of mitotic figures indicating an increased number of basaloid cells. These features are in agreement with those described by Kaddu. Hence, we diagnosed the lesions observed in both cases as proliferating pilomatricomas. Both cases presented with pilomatricomas at the same time, with one patient having a further history of resection of calcified tumours. Although Kaddu did not refer to complication of pilomatricomas, complication of other calcified tumours might be one of the clinical features of proliferating pilomatricoma. A large number of patients with proliferating pilomatricoma would need to be analysed to define its clinical features. Pilomatricoma, proliferating pilomatricoma, and pilomatrical carcinoma show features of hair matrix differentiation.1e3 It is difficult to diagnose pilomatrical tumours based on the clinical features.4e7 Hence, the diagnosis needs to be confirmed with histopathological and cytomorphological examinations.1e3,8e10 Kaddu reported that an incompletely excised proliferating pilomatricoma may have a greater potential for local recurrence compared to ordinary pilomatricomas and presented an example of local recurrence in one patient. It is not presently known
Figure 5
814
A. Sakai et al.
Figure 6
whether proliferating pilomatricoma is a precursor of pilomatrical carcinoma. Therefore, all of these neoplasmas should be excised with adequate surgical margins, and careful follow-up examinations are strongly recommended in all of these patients. In conclusion, proliferating pilomatricoma represents a distinctive histopathological entity; it should be differentiated from other benign and malignant neoplasms with features of hair matrix differentiation.
References 1. Kaddu S, Soyer HP, Wolf IH, et al. Proliferating pilomatricoma. J Cutan Pathol 1997;24:228e34. 2. Elder D. Lever’s Histopathology of Skin. 8th ed. Philadelphia: Lippincott Williams & Wilkins; 1997. p. 757e9.
3. Rosai J. Ackerman’s Surgical Pathology. 8th ed. St. Louis: Mosby; 1996. p. 138. 4. Aslan G, Erdogan B, Akoz T, et al. Multiple occurrence of pilomatrixoma. Plast Reconstr Surg 1996;98:510e3. 5. Brandner MD, Bunkis J. Pilomatrixoma presenting as a parotid mass. Plast Reconstr Surg 1986;78:518e21. 6. Sasaki CT, Yue A, Enriques R. Giant calcifying epithelioma. Arch Otolaryngol 1976;102:753e5. 7. Kaddu S, Soyer HP, Cerroni L, et al. The clinical and histopathologic spectrum of pilomatricomas in adults. Int J Dermatol 1994;33:705e8. 8. Marrogi AJ, Wick MR, Dehner LP. Pilomatrical neoplasms in children and young adults. Am J Dermatopathol 1992;14:87e94. 9. Hardisson D, Linares MD, Cuevas-Santos J, et al. Pilomatrix carcinoma: a clinicopathologic study of six cases and review of the literature. Am J Dermatopathol 2001;23:394e401. 10. Mcculloch TA, Singh S, Cotton DW. Pilomatrix carcinoma and multiple pilomatrixomas. Br J Dermatol 1996;134:368e71.