A Rare Case of Lower Back Swelling Diagnosed as Low- Grade Trichoblastic Carcinoma Following Excision: A Case Report

Saad Shibli Jbour^1, , Malaz Babiker Mustafa², Philipp August Von Breitenbuch³, Omar Bekdache³ and Amna Zia Ahmad⁴

¹Specialist General surgery STMC, Al-Ain,UAE

²Clinical attachment in General surgery department STMC, Al-Ain,UAE

³Consultant General Surgery STMC, Al-Ain, UAE

⁴Consultant Histopathologist STMC, Al-Ain,UAE

Cite this paper:
Saad Shibli Jbour, Malaz Babiker Mustafa, Philipp August Von Breitenbuch, Omar Bekdache and Amna Zia Ahmad. A Rare Case of Lower Back Swelling Diagnosed as Low- Grade Trichoblastic Carcinoma Following Excision: A Case Report. American Journal of Medical Case Reports. 2025; 13(2):5-8. doi: 10.12691/ajmcr-13-2-1

Abstract

Background: Trichoblastic carcinoma is a rare, low-grade malignant tumor arising from hair follicle cells, often presenting in the head and neck region. Diagnosing this tumor can be challenging, especially when it mimics benign lesions such as sebaceous cysts or pilomatricomas. This case report describes an uncommon occurrence of low-grade trichoblastic carcinoma in the lower back, highlighting the diagnostic complexities and management strategies. Case Report: A 51-year-old female with multiple comorbidities, including HIV and HPV 18 and 39 positivity, presented with a chronic lower back swelling and mild pain that had been present for several months. Ultrasound imaging initially suggested a benign lesion such as a sebaceous cyst or pilomatricoma. After excision, histopathological examination revealed a low-grade trichoblastic carcinoma, characterized by basaloid cells, horn cysts, and sebaceous differentiation. The patient underwent a second wide excision due to positive surgical margins, and subsequent pathology confirmed complete tumor removal with no residual malignancy. Discussion: Trichoblastic carcinoma can present as a painless or mildly painful nodule, and its diagnosis is often delayed or misdiagnosed due to its benign clinical appearance. Histopathological analysis remains essential for accurate diagnosis. Although generally low-grade, this carcinoma can show local aggression and recurrence, particularly with positive surgical margins. The role of HPV in the development of skin cancers, especially in immunocompromised individuals, warrants further investigation. Conclusion: Trichoblastic carcinoma should be considered in the differential diagnosis of persistent cutaneous masses, especially those that do not resolve or show growth. Histopathological examination is crucial for diagnosis, and achieving clear surgical margins is essential to prevent recurrence. Regular follow-up is recommended, particularly in patients with HPV positivity.

Keywords:
Trichoblastic carcinoma Lower back swelling Malignant tumor Histopathology Excision HPV 18 and 39 Diagnosis Skin cancer Surgical margins Immunocompromised patient

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References:

[1]	Leeman A, de Cuba EMV, Jaspars LH, Quint KD, Genders RE. A low-grade trichoblastic carcinoma treated with Mohs micrographic surgery: Case Report in Dermatology.2021 January; 129-133.
[2]	Michelle A Boettler, Kathryn T Shahwan , Nadia Y Abidi , David R Carr. Trichoblastic carcinoma: a comprehensive review of the literature. 2022 Jul; 314(5): 399-403.
[3]	Parth Patel, Shiri Nawrocki, Kelsey Hinther, Amor Khachemoune. Trichoblastomas Mimicking Basal Cell Carcinoma: The Importance of Identification and Differentiation. 2020 May 25; 12(5): e8272.
[4]	Eshraghi B, Riazi-Esfahani H, Katoozpour R, Anvari P, Mortazavi M, Asadi Amoli F. Trichoblastoma of the upper eyelid. J Ophthalmic Vis Res 2017; 12: 219-21.
[5]	Karagas MR, Nelson HH, Sehr P et al. Human papillomavirus infection and incidence of squamous cell and basal cell carcinomas of the skin. J Natl Cancer Inst 2006; 98: 389–395.