International Journal of Trichology International Journal of Trichology
 Print this page Email this page Small font sizeDefault font sizeIncrease font size
  Home | About IJT | Editorial board | Search | Ahead of print | Current Issue | Archives | Instructions | Online submission | Subscribe | Advertise | Contact us | Login   

 Table of Contents  
Year : 2012  |  Volume : 4  |  Issue : 4  |  Page : 280-282  

Cytodiagnosis of Pilomatrixoma from an Uncommon Site with Unusual Presentation

Department of Pathology, Bankura Sammilani Medical College, Bankura, West Bengal, India

Date of Web Publication26-Apr-2013

Correspondence Address:
Jyoti Prakash Phukan
Department of Pathology, Bankura Sammilani Medical College, P.O. Kenduadihi, Bankura - 722 102, West Bengal
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0974-7753.111205

Rights and Permissions

Pilomatrixoma or pilomatricoma is an uncommon benign tumor of hair matrix origin, which most commonly occurs in the head and neck region and upper extremities. In this study, we report a case of pilomatrixoma of a 35-year-old female presenting with left-leg swelling with surface ulceration, clinically thought to be malignant. Fine-needle aspiration cytology (FNAC) of the lesion showed clusters of basaloid cells with round to ovoid nuclei, nucleated squamous cells, and anucleated squames and clusters of shadow cells. Acytological diagnosis of pilomatrixoma was made. Subsequent surgical excision and histopathological examination confirmed the diagnosis. This case highlights a rare site of presentation and the role of FNAC in preoperative diagnosis of this benign tumor for proper management.

Keywords: Fine-needle aspiration cytology, pilomatricoma, pilomatrixoma

How to cite this article:
Phukan JP, Sinha A, Biswas S. Cytodiagnosis of Pilomatrixoma from an Uncommon Site with Unusual Presentation. Int J Trichol 2012;4:280-2

How to cite this URL:
Phukan JP, Sinha A, Biswas S. Cytodiagnosis of Pilomatrixoma from an Uncommon Site with Unusual Presentation. Int J Trichol [serial online] 2012 [cited 2021 Oct 28];4:280-2. Available from:

   Introduction Top

Pilomatrixoma or pilomatricomais a relatively uncommon benign tumor that originates from the matrix cells at the base of the hair. [1] The most common location of this tumor is the head and neck region, followed by the upper extremities and rarely in the lower extremities. [2],[3] It presents as a solitary, slow-growing dermal or subcutaneous nodule; however, clinical diagnosis is often difficult or misdiagnosed. [4],[5] Histologic features of this tumor are well recognized, but cytological features often produce diagnostic difficulties. [6]

   Case Report Top

A 35-year-old female presented with a nodular ulcerated swelling measuring 3 × 2.5 cm over the left lower leg since the past 5 years [Figure 1]. The nodular lesion was well-circumscribed, firm with surface ulceration. The patient attended Fine-needle aspiration cytology (FNAC) clinic with a clinical suspicion of malignancy. On physical examination, the lesion was not fixed to the underlying bone and no inguinal lymphadenopathy was detected.

Fine-needle aspiration was performed using a 22-gauge needle. Cytological smears were cellular, showing clusters of basaloid cells having round to oval nuclei, nucleated squamous cells, and anucleated squames. Few fragments of shadow cells adherent to basaloid cells were also noted [Figure 2]a and b. A cytological diagnosis of pilomatrixoma was made.
Figure 1: External clinical photograph. Ulcerated nodular lesion in the lower leg

Click here to view
Figure 2: Fine-needle aspiration cytology showing (a) clusters of basaloid cells admixed with squamous cells and anucleated squames (May-Grünwald-Giemsa ×200); and (b) cluster of shadow cells adherent to basaloid cells (MGG, ×400)

Click here to view

Excision biopsy and histopathologic examination of the resected specimen showed typical features of pilomatrixoma with basaloid cells in the periphery, shadow cells toward the center, and a few foreign body-type giant cells [Figure 3]a and b.
Figure 3: Sections showing (a) islands of basaloid cells and shadow cells with surrounding foreign body giant cells and inflammatory cells (H and E, ×100); Inset: Showing shadow cells in higher magnification; and (b) basaloid cells in higher magnification (H and E, ×400)

Click here to view

   Discussion Top

Pilomatrixoma is a relatively uncommon benign tumor of hair matrix differentiation, first described by Malherbe as benign calcifying epithelioma, as a tumor of the sebaceous gland. [7] Later on, the term was changed to "pilomatrixoma' because of its histogenesis from hair matrix cells. [1] The most common sites involved in this tumor are the head and neck region, followed by the upper extremities, trunk, andthe lower extremities. [2],[3],[8] This tumor usually occurs in children younger than 10 years of age and also in the second decade of life. [9] They are more commonly seen in women.

Clinically, this tumor presents as a soft to firm subcutaneous mass with intact overlying skin with average size 1.6 cm. [8] Correct clinical diagnosis is very rare and differential diagnosis includes epidermal cyst, dermoid cyst, cysticercosis, sebaceous cyst, sebaceous adenoma or carcinoma, capillary hemangioma, chalazion, rhabdomyosarcoma, and so on. [2],[8],[10] FNA of the lesion commonly reveals basaloid cells, squamous cells, anucleate squames, shadow cells, foreign-body giant cells, polymorphs, and calcification in variable frequencies. [8] As all these findings are not present in a single case, cytological misdiagnosis is common and includes epidermal inclusion cyst, adnexal tumor, squamous cell carcinoma, basal cell carcinoma, mucoepidermoid carcinoma, or even round-cell tumor. [8],[11],[12] When aspirates contain mainly nucleated squamous cells and squames, it leads to a wrong diagnosis of epidermal inclusion cyst. Predominance of basaloid cells can give a misdiagnosis of basal cell carcinoma or even round-cell tumor. In aspirates of pilomatrixoma, the presence of foreign-body giant cells is also variable. Moreover, they can be found in other lesions such as epidermal inclusion cysts, ruptured benign cysts, and panniculitis to squamous cell carcinoma. [8] Extreme calcification in pilomatrixoma may yield only calcified material and proper diagnosis may not possible. Hence, cytology has some limitations in the diagnosis of pilomatrixoma. Histopathologic examination provides the correct diagnosis and shows solid nests of basaloid cells with the formation of ghost cells with foreign-body giant-cell reaction, calcification, and ossification in some cases.

Our patient presented with an ulcerated nodule in the left lower leg. Clinical diagnosis of squamous cell carcinoma was given. In our case, FNAC yielded basaloid cells, squamous cells, anucleate squames, and shadow cells; which helped us arrive at a correct preoperative diagnosis. Histopathology also confirmed the diagnosis.

In our case, the site of the lesion, which was very uncommon, and the presence of surface ulceration led to a clinical misdiagnosis. Knowledge of the morphological spectrum of characteristic cellular components helps in correct preoperative diagnosis of pilomatrixoma by FNAC and helps in proper patient management.

Lastly, we have presented this case because of the rare location of the tumor and the malignant clinical presentation. This case also highlights the role of FNAC in arriving at a correct preoperative diagnosis.

   References Top

1.Forbis R Jr, Helwig EB. Pilomatrixoma (calcifying epithelioma). Arch Dermatol 1961;83:606-18.  Back to cited text no. 1
2.Yap EY, Hohberger GG, Bartley GB. Pilomatrixoma of the eyelids and eyebrows in children and adolescents. Ophthal Plast Reconstr Surg 1999;15:185-9.  Back to cited text no. 2
3.Cypel TK, Vijayasekaran V, Somers GR, Zuker RM. Pilomatricoma: Experience of the hospital for sick children. Can J Plast Surg 2007;15:159-61.  Back to cited text no. 3
4.Kumaran N, Azmy A, Carachi R, Raine PA, Macfarlane JH, Howatson AG. Pilomatrixoma - Accuracy of clinical diagnosis. J Pediatr Surg 2006;41:1755-8.  Back to cited text no. 4
5.Roche NA, Monstrey SJ, Matton GE. Pilomatricoma in children: Common but often misdiagnosed. Acta Chir Belg 2010;110:250-4.  Back to cited text no. 5
6.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.  Back to cited text no. 6
7.Peterson WC Jr, Hult AM. Calcifying Epithelioma of Malherbe. Arch Dermatol 1964;90:404-10.  Back to cited text no. 7
8.Bansal C, Handa U, Mohan H. Fine needle aspiration cytology of pilomatrixoma. J Cytol 2011;28:1-6.  Back to cited text no. 8
[PUBMED]  Medknow Journal  
9.Sivakumar S. Pilomatrixoma as a diagnostic pitfall in fine needle aspiration cytology: A case report. Acta Cytol 2007;51:583-5.  Back to cited text no. 9
10.Ali MJ, Honavar SG, Naik MN, Vemuganti GK. Malherbe's calcifying epithelioma (Pilomatrixoma): An uncommon perioculartumor. Int J Trichology 2011;3:31-3.  Back to cited text no. 10
11.Lemos MM, Kindblom LG, Meis-Kindblom JM, Ryd W, Willén H. Fine-needle aspiration features of pilomatrixoma. Cancer 2001;93:252-6.  Back to cited text no. 11
12.Agrawal L, Kaur P, Singh J, Singh N. Pilomatrixoma misdiagnosed as round cell tumor on fine-needle aspiration cytology. Indian J Cancer 2010;47:483-5.  Back to cited text no. 12
[PUBMED]  Medknow Journal  


  [Figure 1], [Figure 2], [Figure 3]

This article has been cited by
1 “Tumour Perplex” called pilomatricoma — Report of a case with confounding chest wall mass in an adult male and its literature review
Sudeep Pradeep Yadav,Priyadarshan Anand Jategaonkar,Smita Priyadarshan Jategaonkar,Satyendranath Mehra
Hellenic Journal of Surgery. 2014; 86(5): 318
[Pubmed] | [DOI]


    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Access Statistics
    Email Alert *
    Add to My List *
* Registration required (free)  

  In this article
   Case Report
    Article Figures

 Article Access Statistics
    PDF Downloaded47    
    Comments [Add]    
    Cited by others 1    

Recommend this journal