Posttraumatic intraosseous epidermoid inclusion cyst. A case report and short literature review

Adrian Dumitru 1 , 2 , Mariana Costache 1 , 2 , Bogdan Şerban 3 , Ionu-Mihai Japie 3 , Dan Anghelescu 3 , Constantin Condrea 4 , Doris Ionescu 2 , Cătălin Aliuş 5 , and Sebastian Grădinaru 2 , 5
  • 1 Department of Pathology, University Emergency Hospital Bucharest, Romania
  • 2 “Carol Davila” University of Medicine and Pharmacy, , Bucharest, Romania
  • 3 Department of Orthopaedics and Traumatology, University Emergency Hospital Bucharest
  • 4 Department of Plastic Surgery, University Emergency Hospital Bucharest, Romania
  • 5 4 Surgery Department, University Emergency Hospital Bucharest, Romania


Epidermoid bone inclusion cysts are pathological structures bordered by a layer of stratified squamous epithelium containing keratin debris. They are also called epidermal bone cysts. Intraosseous epidermoid cysts are rare entities; these lesions may occur as a result of trauma (puncture wound or pressure erosion).

They appear to be well defined, translucent lytic lesions with sclerotic margins on imaging studies. The most frequent sites affected are: the distal phalanx and the calvaria - intradiploic, but a few cases of larger bone involvement have been reported. The imagistic differential diagnosis of this lesion includes intraosseous extension of a glomus tumor, enchondroma, osteoid osteoma, acral metastases, some primary vascular bone tumors, giant cell reparative granuloma, subungual nodular melanoma or other lytic non-neoplastic lesions such as osteomyelitis. We present the case of a 70-year-old man experiencing anxiety and pain due to distal phalanx expansion of the IV digit, following hand trauma. An X-ray was performed, showing a radiotransparent lesion located in the distal phalanx. An intramedullary inclusion cyst must be taken into account as a clinical differential diagnosis. Due to the extensive destruction of the distal phalanx, amputation was necessary. Gross examination of the surgical specimen revealed a cystic lesion that contained whitish, creamy material with extensive necrotic areas. Microscopic examination revealed a ruptured intraosseous epidermoid inclusion cyst, which was successfully excised.

If the inline PDF is not rendering correctly, you can download the PDF file here.

  • 1. Santini-Araujo E et al (eds.). Tumors and Tumor-Like Lesions of Bone: For Surgical Pathologists, Orthopedic Surgeons and Radiologists. 2015, London, Springer-Verlag. doi: 10.1007/978-1-4471-6578-1-50.

  • 2. Patel K et al. Epidermal inclusion cyst of phalanx: a case report and review of the literature. Skeletal Radiol. 2006; 35(11):861–3.

  • 3. Loxha MP, Salihu S, Kryeziu K et al. Epidermoid Cyst of Mandible Ramus: Case Report. Med Arch. 2016; 70(3):238-240. doi:10.5455/medarh.2016.70.238-240.

  • 4. Schajowicz F, Aiello C, Slullitel I. Cystic and pseudocystic lesions of the terminal phalanx with special reference to epidermoid cysts. Clin Orthop. 1970; 68:84–92.

  • 5. Singh V, Gupta S, Jaiswal R, Malkunje L. Intra osseous dermoid cyst of mandible - a rare case report. Open Journal of Stomatology. 2012; 2:153-6.

  • 6. Baykal C, Yazganoğlu K. Clinical atlas of skin tumors. 2014, Springer Sci. Bus. Media.

  • 7. Takemura N, Fujii N, Tanaka T. Epidermal cysts: the best surgical method can be determined by ultrasonographic imaging. Clin. Exp. Dermatol. 2007; 32(4):445–447.

  • 8. Zito P. F. Cyst Schar, Epidermoid (Sebaceous Cyst). 2019, Treasure Island (FL), StatPearls Publishing.

  • 9. Wollina U, Langner D, Tchernev G, França K, Lotti T. Epidermoid cysts - A wide spectrum of clinical presentation and successful treatment by surgery: a retrospective 10-year analysis and literature review. Open Access Maced. J. Med. Sci. 2018; 6(1):28–30.

  • 10. Wang BY, Eisler J, Springfield D, Klein MJ. Intraosseous Epidermoid Inclusion Cyst in a Great Toe. Archives of Pathology & Laboratory Medicine. July 2003; 127(7):e298-e300.

  • 11. Tamburrelli F. A case of epidermoid cysts of the distal phalanx of the big toe [in Italian]. Arch Putti Chir Organi Mov. 1984; 34:417–422.

  • 12. Shibata T, Hatori M, Satoh T, Ehara T, Kokubun S. Magnetic resonance imaging features of epidermoid cyst in the extremities. Arch. Orthop. Trauma Surg. 2003; (123):239–241.

  • 13. Yang D, Yoon M, Kim H, Oh Y, Ha S, Oh J et al. Presacral epidermoid cyst: imaging findings with histopathologic correlation. Abdom. Imaging. 2001; 26(1):79–82.

  • 14. Hong S, Chung H, Choi J, Koh Y, Choi J, Kang H. MRI findings of subcutaneous epidermal cysts: emphasis on the presence of rupture. AJR Am. J. Roentgenol. 2006; 186(4):961–966.

  • 15. Libson E, Bloom RA, Husband JE, Stoker DJ. Metastatic tumors of bone of the hand and foot: a comparative review and report of 43 additional cases. Skeletal Radiol. 1987; 16:387–392.

  • 16. Handa U, Kumar S, Mohan H. Aspiration cytology of epidermoid cyst of terminal phalanx. Diagn Cytopathol. 2002; 26:266–267.

  • 17. Eimani MT, Kumar PV. Epidermoid cyst of the terminal phalanx of the right thumb diagnosed by fine needle aspiration cytology [letter]. Acta Cytol. 1999; 43:326–328.


Journal + Issues