Pilar Cyst: A Case Report

Dr Archana S^*, Dr (Col) Suresh Menon¹, Dr ME Sham², Dr Veerendra Kumar³, Dr Sheron Mathews⁴, Dr Romir Navaneetham⁵

1. MDS (Professor and HOD), Department of Oral Maxillofacial Surgery, Vydehi Institute of Dental Sciences.
2.  MDS MRMS PhD (Professor), Department of Oral Maxillofacial Surgery, Vydehi Institute of Dental Sciences.
3.  MDS (Reader), Department of Oral Maxillofacial Surgery, Vydehi Institute of Dental Sciences.
4. MDS (Assistant Professor), Department of Oral Maxillofacial Surgery, Vydehi Institute of Dental Sciences.
5. MDS (Surgical Resident), Department of Oral Maxillofacial Surgery, Vydehi Institute of Dental Sciences.

Corresponding Author: Dr Archana S, MDS (Assistant Professor), Department of Oral Maxillofacial Surgery, Vydehi Institute of Dental Sciences.

Copy Right: © 2022 Dr Archana S, this is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Received Date: February 21, 2022

Published Date: March 01, 2022

Abstract

Trichilemmal or pilar cyst is a rare tumour which arises from outer root sheath of hair follicles. It could be tricky to distinguish both clinically from other skin lesions.In this report a case of 42 year old male with a one year history of painless growth on the left side of the face has been reported. Post excisional biopsy Pilar Cyst diagnosis was given.

Key Word: Pilar Cyst, Trichilemmal Cyst, Maxillofacial Region

Introduction

Trichiemmal cyst or pilar cyst was first identified Pinkus as keratinization of outer root sheath of hair follicle which were originally called a sebaceous cyst. (1) The trichilemmal cyst is the 2nd most common cyst in the head and neck region and occur in 5 – 10% of the population. They are found 90% of the time in the scalp. The common cystic lesions of the skin are sebaceous cysts.  Proliferating trichilemmal cyst grow rapidly and may arise denervo.  Pilar cysts are almost always benign with malignant transformation occurring rarely. Malignant transformation may lead to distant metastasis too. However there are no distinct clinical criteria’s that can distinguish benign and a malignant proliferating trichilemmal cyst. (2) These cysts are thought to be genetically inherited. Malignant transformation of these cysts to a squamous cell carcinoma or spindle cell carcinoma is a rare phenomenon. (3)

This case report illustrates a diagnosis of a trichilemmal cyst

 
Case Report

A 42 year old male presented with a complaint of swelling on the left side of the face since 1 year. Patient gives a history that the swelling started off as a pea sized growth and gradually progressed to the present size. The swelling was asymptomatic and patient wanted to get it removed due to aesthetic reasons. On examination the swelling was well circumscribed measuring about 1x1 cm. Present 1 cm lateral to the left lateral canthi region. The swelling was soft in consistency, freely movable, non-tender, and skin over the swelling appeared normal. No palpable lymph nodes noted. A clinical provisional diagnosis of a sebaceous cyst was given and patient was advised excision under local anaesthesia for the same. (Figure 1)

An elliptical incision was given over the swelling, blunt dissection was done and the lesion was removed in toto. (Figure 2) Closure was done using Ethilon 5-0. Antibiotics and Analgesics were prescribed. On histopathological analysis a diagnosis of Trichilemmal/ Pilar Cyst was given.

Discussion

Pilar cyst is a benign lesion of the skin. Patients usually are of middle aged, predominantly women. The pathology is long standing occasionally since childhood. Multiple cysts have also been reported in different skin regions of the body. (4) It has been described to have been associated with syndromes and maybe triggered by local trauma. There have been reports of familial accumulation of isolated lesions. In this kind of cysts a high proliferated activity is noted the entity is termed as proliferative trichilemmal cyst. The clinical distinction between a benign trichilemmal tumour and a squamous cell carcinoma can be difficult or impossible. It can mimic a turban tumour also. (5)

Further studies and extensive clinical evaluation will be necessary to understand the clinical behaviour of this pathology. (6) In our case that has been reported an excision of a pilar cyst was done which closely mimicked a sebaceous cyst clinically, the histopathological evidence proved.

Conclusion

A pilar cyst can mimic a common skin lesion such as a sebaceous cyst. The diagnosis however depends on histopathological examination of the pathology. The tumour in literature has been reported to have behaved aggressively and hence adequate excision and appropriate follow up is required. (7)

References

1. Liu M, Han H, Zheng Y, Xiao S, Feng Y. Pilar “cyst on the dorsum of hand”. Medicine. 2020;99(31):e21519.
2. Ramaswamy A, Manjunatha H, Sunilkumar B, Arunkumar S. “Morphological spectrum of Pilar cysts”. North American Journal of Medical Sciences. 2013;5(2):124.
3.  Sasikumar R, Sabarad P, Krishna KV, Devasia J. “True Trichilemmal Cyst or Pilar Cyst: A Case Report”. Oral Maxillofac Pathol J 2019;10(1):41-43.
4. Siadat A, Asilian A, Shahmoradi Z, Shariat S, Moghadam N, Soozangar H. “Multiple giant pilar cyst distributed over the body since childhood”. Indian Journal of Dermatology. 2016;61(1):121.
5. Friedrich R, Wilczak W. “Multiple Trichilemmal Cysts of the Scalp”. Anticancer Research. 2019;39(8):4253-4258.
6. Vargas-Mora P, Orlandi D, Morales C, Araya I. “Proliferating trichilemmal cysts: A clinicopathological study of 14 cases”. International Journal of Trichology. 2019;11(6):258.
7. Short E, O'Shea A, Mukkanna K, Patel G, Docjinov S, May K. “Case Report: A rapidly growing cyst on the scalp”. F1000Research. 2019;8:779.