Clinical and Experimental Dermatology
Acquired hypopigmented suprapubic macules lez-Ensen ~ at1 I. Pau-Charles,1 A. Vicente,1 C. Jou2 and M. A. Gonza Departments of 1Dermatology and 2Pathology, Hospital Sant Joan de Deu, Universitat de Barcelona, Esplugues de Llobregat, Barcelona, Spain doi: 10.1111/ced.12319
Clinical findings A healthy 3-year-old girl from South America presented with a 2-year history of several progressively developing, asymptomatic, hypopigmented lesions on her abdomen. Physical examination revealed the presence of around 40 small hypopigmented macules grouped in the suprapubic area, without inflammatory changes or scaling (Fig. 1). Skin scrapings were obtained for direct potassium hydroxide examination, and mycological and bacteriological culture, which all yielded negative results. Lesional skin swabs were assessed for human papillomavirus DNA using PCR, with negative results. The patient’s latest available blood tests, which included a chemistry panel and a complete blood count, were normal.
Figure 1 Asymptomatic hypopigmented macules on the supra-
pubic area.
Histopathological findings On histological examination, scattered intraepidermic clear cells were seen, mainly in the lower half of the epidermis (Fig. 2a). These cells showed positivity to epithelial membrane antigen (Fig. 2b), cytokeratin 7 (Fig. 2c) and carcinoembryonic antigen (Fig. 2d). There were no inflammatory changes associated. What is your diagnosis?
Correspondence: Dr Ignasi Pau-Charles, Department of Dermatology, Hospital Sant Joan de D eu. Universitat de Barcelona, Passeig Sant Joan de Deu, 2 08950 Esplugues de Llobregat, Barcelona, Spain E-mail: [email protected] Conflict of interest: the authors declare that they have no conflicts of interest. Accepted for publication 1 December 2013
ª 2014 British Association of Dermatologists
Clinical and Experimental Dermatology (2014) 39, pp655–657
655
D CP
CED
CPD • Clinicopathological case
D
CP
Clinicopathological case
(a)
(b)
(c)
(d)
Figure 2 (a) Intraepidermic clear cells (indicated by asterisk) (haematoxylin and eosin, original magnification 9200) showing positivity
to (b) epithelial membrane antigen, (c) cytokeratin 7 and (d) carcinoembryonic antigen.
Diagnosis
Clear cell papulosis (CCP).
Discussion CCP is a benign and infrequent condition, but is probably underdiagnosed.1 The majority of patients that have been reported are from Asian countries (both South and East Asia). To our knowledge, only four non Asian cases of CCP (three children of Hispanic origin and one child from Italy) have been published.2 Onset of CCP usually takes place before the age of 2 years, and presents as asymptomatic hypopigmented macules and or flat papules, usually on the lower abdomen. Isolated lesions may appear on other skin areas. The histopathological findings can be very subtle, and may go unnoticed by the pathologist if the
656
Clinical and Experimental Dermatology (2014) 39, pp655–657
clinician does not raise the diagnostic suspicion of CCP. However, scattered round clear cells can often be identified in the lower half of the epidermis, either isolated or in small clusters. They can morphologically resemble melanocytes or Langerhans cells, but are S100-negative. They can also resemble Toker cells, a type of intraepidermal clear cell usually found in the nipple, but Toker cells are mucin-negative, whereas the clear cells in CCP can sometimes be mucin-positive. The immunohistochemical profile of CCP clear cells is similar to that of Paget cells, showing positivity to epithelial membrane antigen (EMA), cytokeratin 7 (CK7) and carcinoembryonic antigen (CEA), among others, a fact that has led some authors to suggest that CCP may be an indolent variant of extramammary Paget disease. More recently, other authors have suggested that clear cells in CCP may be ectopic intraepidermal eccrine secretory cells.3
ª 2014 British Association of Dermatologists
D CP Clinicopathological case
The clinical differential diagnosis of CCP includes other causes of acquired hypopigmented/achromic lesions such as pityriasis alba, post-inflammatory hypopigmentation, vitiligo, pityriasis versicolor, flat warts and hypopigmented mycosis fungoides. The histopathological differential diagnosis includes, apart from the aforementioned cell types and normal skin, conditions such as pagetoid dyskeratosis, mammary/extramammary Paget disease, sebaceous carcinoma and in situ squamous cell carcinoma with pagetoid cells, among others. CCP has not been shown to be associated with other diseases, and no malignant transformation has been reported. A recent long-term follow-up study of CCP has shown that lesions tend to regress spontaneously over time,4 as observed in our patient, in whom approximately half of the lesions had cleared after 1 year. No treatment is therefore required; however, clinical follow-up is recommended.
Learning points
•
CCP is a benign self-limiting condition, presenting with acquired hypopigmented macules on the lower abdomen of children under the age of 2 years.
ª 2014 British Association of Dermatologists
•
Histological findings can be very subtle, and may go unnoticed. • Scattered intraepidermal clear cells show positivity to EMA, CK-7 and CEA, and are variably positive for mucin. • CCP should be included in the differential diagnosis of acquired hypopigmented lesions to avoid invasive diagnostic procedures and unnecessary treatments.
References 1 Wysong A, Sundram U, Benjamin L. Clear-cell papulosis: a rare entity that may be misconstrued pathologically as normal skin. Pediatr Dermatol 2012; 29: 195–8. 2 Benouni S, Kos L, Ruggeri SY, North PE, Drolet BA. Clear cell papulosis in Hispanic siblings. Arch Dermatol 2007; 143: 358–60. 3 Kim YC, Mehregan DA, Bang D. Clear cell papulosis: an immunohistochemical study to determine histogenesis. J Cutan Pathol 2002; 29: 11–4. 4 Tseng FW, Kuo TT, Lu PH, Chan HL, Chan MJ, Hui RC. Long-term follow-up study of clear cell papulosis. J Am Acad Dermatol 2010; 63: 266–73.
Clinical and Experimental Dermatology (2014) 39, pp655–657
657
Acquired hypopigmented suprapubic macules lez-Ensen ~ at1 I. Pau-Charles,1 A. Vicente,1 C. Jou2 and M. A. Gonza Departments of 1Dermatology and 2Pathology, Hospital Sant Joan de Deu, Universitat de Barcelona, Esplugues de Llobregat, Barcelona, Spain doi: 10.1111/ced.12319
Clinical findings A healthy 3-year-old girl from South America presented with a 2-year history of several progressively developing, asymptomatic, hypopigmented lesions on her abdomen. Physical examination revealed the presence of around 40 small hypopigmented macules grouped in the suprapubic area, without inflammatory changes or scaling (Fig. 1). Skin scrapings were obtained for direct potassium hydroxide examination, and mycological and bacteriological culture, which all yielded negative results. Lesional skin swabs were assessed for human papillomavirus DNA using PCR, with negative results. The patient’s latest available blood tests, which included a chemistry panel and a complete blood count, were normal.
Figure 1 Asymptomatic hypopigmented macules on the supra-
pubic area.
Histopathological findings On histological examination, scattered intraepidermic clear cells were seen, mainly in the lower half of the epidermis (Fig. 2a). These cells showed positivity to epithelial membrane antigen (Fig. 2b), cytokeratin 7 (Fig. 2c) and carcinoembryonic antigen (Fig. 2d). There were no inflammatory changes associated. What is your diagnosis?
Correspondence: Dr Ignasi Pau-Charles, Department of Dermatology, Hospital Sant Joan de D eu. Universitat de Barcelona, Passeig Sant Joan de Deu, 2 08950 Esplugues de Llobregat, Barcelona, Spain E-mail: [email protected] Conflict of interest: the authors declare that they have no conflicts of interest. Accepted for publication 1 December 2013
ª 2014 British Association of Dermatologists
Clinical and Experimental Dermatology (2014) 39, pp655–657
655
D CP
CED
CPD • Clinicopathological case
D
CP
Clinicopathological case
(a)
(b)
(c)
(d)
Figure 2 (a) Intraepidermic clear cells (indicated by asterisk) (haematoxylin and eosin, original magnification 9200) showing positivity
to (b) epithelial membrane antigen, (c) cytokeratin 7 and (d) carcinoembryonic antigen.
Diagnosis
Clear cell papulosis (CCP).
Discussion CCP is a benign and infrequent condition, but is probably underdiagnosed.1 The majority of patients that have been reported are from Asian countries (both South and East Asia). To our knowledge, only four non Asian cases of CCP (three children of Hispanic origin and one child from Italy) have been published.2 Onset of CCP usually takes place before the age of 2 years, and presents as asymptomatic hypopigmented macules and or flat papules, usually on the lower abdomen. Isolated lesions may appear on other skin areas. The histopathological findings can be very subtle, and may go unnoticed by the pathologist if the
656
Clinical and Experimental Dermatology (2014) 39, pp655–657
clinician does not raise the diagnostic suspicion of CCP. However, scattered round clear cells can often be identified in the lower half of the epidermis, either isolated or in small clusters. They can morphologically resemble melanocytes or Langerhans cells, but are S100-negative. They can also resemble Toker cells, a type of intraepidermal clear cell usually found in the nipple, but Toker cells are mucin-negative, whereas the clear cells in CCP can sometimes be mucin-positive. The immunohistochemical profile of CCP clear cells is similar to that of Paget cells, showing positivity to epithelial membrane antigen (EMA), cytokeratin 7 (CK7) and carcinoembryonic antigen (CEA), among others, a fact that has led some authors to suggest that CCP may be an indolent variant of extramammary Paget disease. More recently, other authors have suggested that clear cells in CCP may be ectopic intraepidermal eccrine secretory cells.3
ª 2014 British Association of Dermatologists
D CP Clinicopathological case
The clinical differential diagnosis of CCP includes other causes of acquired hypopigmented/achromic lesions such as pityriasis alba, post-inflammatory hypopigmentation, vitiligo, pityriasis versicolor, flat warts and hypopigmented mycosis fungoides. The histopathological differential diagnosis includes, apart from the aforementioned cell types and normal skin, conditions such as pagetoid dyskeratosis, mammary/extramammary Paget disease, sebaceous carcinoma and in situ squamous cell carcinoma with pagetoid cells, among others. CCP has not been shown to be associated with other diseases, and no malignant transformation has been reported. A recent long-term follow-up study of CCP has shown that lesions tend to regress spontaneously over time,4 as observed in our patient, in whom approximately half of the lesions had cleared after 1 year. No treatment is therefore required; however, clinical follow-up is recommended.
Learning points
•
CCP is a benign self-limiting condition, presenting with acquired hypopigmented macules on the lower abdomen of children under the age of 2 years.
ª 2014 British Association of Dermatologists
•
Histological findings can be very subtle, and may go unnoticed. • Scattered intraepidermal clear cells show positivity to EMA, CK-7 and CEA, and are variably positive for mucin. • CCP should be included in the differential diagnosis of acquired hypopigmented lesions to avoid invasive diagnostic procedures and unnecessary treatments.
References 1 Wysong A, Sundram U, Benjamin L. Clear-cell papulosis: a rare entity that may be misconstrued pathologically as normal skin. Pediatr Dermatol 2012; 29: 195–8. 2 Benouni S, Kos L, Ruggeri SY, North PE, Drolet BA. Clear cell papulosis in Hispanic siblings. Arch Dermatol 2007; 143: 358–60. 3 Kim YC, Mehregan DA, Bang D. Clear cell papulosis: an immunohistochemical study to determine histogenesis. J Cutan Pathol 2002; 29: 11–4. 4 Tseng FW, Kuo TT, Lu PH, Chan HL, Chan MJ, Hui RC. Long-term follow-up study of clear cell papulosis. J Am Acad Dermatol 2010; 63: 266–73.
Clinical and Experimental Dermatology (2014) 39, pp655–657
657
