November 2025 in “JPRAS Open” This study reported that age and diabetes are major factors influencing trichilemmal cyst development and size, highlighting the importance of these conditions for risk assessment and surgical planning.
5 citations
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January 2014 in “Journal of Cutaneous and Aesthetic Surgery” A woman had 13 non-cancerous cysts on her scalp successfully removed in one surgery.
3 citations
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March 2013 in “American Journal of Dermatopathology” This study found that ossification in trichilemmal cysts may be more common than previously thought, often associated with cyst wall rupture, and reports a novel case of ossifying TC with extramedullary hematopoiesis.
2 citations
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November 2020 in “The American journal of dermatopathology/American journal of dermatopathology” In this study, sweat duct differentiation was found to be a rare feature in trichilemmal cysts, occurring in only 0.97% of cases, and was likely under recognized.
2 citations
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June 2001 in “Medical Electron Microscopy” This study observed that the keratinization pattern of trichilemmal cysts in two Japanese women may originate from the proliferation of the outer root sheath in the follicular isthmus of anagen hairs.
1 citations
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March 2023 in “Journal of Ultrasound in Medicine” In this study, ultrasound showed promise in differentiating trichilemmal cysts from epidermoid cysts, suggesting potential value for clinical management.
1 citations
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August 2021 This case report describes a 10-year-old patient with a rare trichilemmal cyst in the cervical region, highlighting the importance of close monitoring due to potential risks of malignancy.
May 2026 in “World Journal of Advanced Research and Reviews” This case report documents a rare instance of a trichilemmal cyst occurring on the plantar surface of the foot, highlighting the necessity of histological examination for accurate diagnosis when clinical or radiological presentations are atypical.
January 2026 in “Indian Journal of Ophthalmology - Case Reports” In this study, a rare case of a trichilemmal cyst in a 6-year-old's upper eyelid was observed; it was identified through histopathological examination after excision, highlighting the importance of considering trichilemmal cysts in atypical pediatric eyelid swellings.
September 2025 in “Journal of Ayurveda and Integrated Medical Sciences” This study described trichilemmal cysts, firm lumps that form from blocked hair follicles, typically found on the scalp but also less commonly on other body parts, affecting less than 10% of the population and possibly inherited as an autosomal dominant trait.
Baricitinib may reactivate trichilemmal cysts in people with a history of these cysts.
November 2023 in “International surgery journal” In this case study, a 69-year-old male with a neck swelling was diagnosed with a trichilemmal cyst, highlighting the importance of complete surgical excision for lesions with proliferative or malignant potential.
September 2021 in “The journal of investigative dermatology/Journal of investigative dermatology” This study identified a germline variant in PLCD1 as a major risk allele for familial trichilemmal cysts, requiring a subsequent somatic mutation in the same allele for cyst formation.
June 2015 in “Sonography” This case report describes a rare instance of multiple sebaceous cysts over the scrotum in a 22-year-old man, highlighting the effectiveness of ultrasound imaging for diagnosis and the need for surgical intervention in severe cases.
9 citations
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December 2012 in “Indian Journal of Dermatology Venereology and Leprology” This study reports a rare case of a 40-year-old woman with multiple calcified trichilemmal cysts, associated with alopecia universalis and suggesting a potential genetic link.
21 citations
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October 2019 in “The journal of investigative dermatology/Journal of investigative dermatology” This study identified specific germline and somatic mutations in the Phospholipase C Delta 1 gene as high-risk factors for developing hereditary trichilemmal cysts, involving a monoallelic two-hit mechanism.
3 citations
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January 1989 in “The Nishinihon Journal of Dermatology” This case report describes a proliferating trichilemmal cyst that underwent malignant transformation, with specific keratins identified in the tumor but no epidermal keratin detected.
2 citations
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June 2023 in “Medicine” This case report describes the occurrence of a very rare disease, MTPC, in the elbow of a man who does not match the typical etiology, highlighting its academic significance.
January 2002 in “Linchuang pifuke zazhi” This report describes an unusual case of proliferating trichilemmal cyst with trichoepitheliomatous change in a young woman, differing from its typical presentation in elderly women.
In this case report, a 65-year-old man's neck lesion was initially misdiagnosed as benign but later identified as trichilemmal carcinoma, with the authors recommending Mohs Micrographic Surgery as the preferred treatment option for this rare condition.
13 citations
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June 2018 in “Dermatopathology” This classification proposal introduces a novel system for categorizing cutaneous adnexal cysts based on their origin in the folliculosebaceous unit and sweat glands, aiming to simplify and enhance understanding of these skin lesions.
April 2018 in “Journal of Investigative Dermatology” This article proposes a new classification system for cutaneous adnexal cysts based on their origin in the folliculo-sebaceous unit and sweat glands, aiming to clarify their categorization and origins.
5 citations
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October 2019 in “The journal of investigative dermatology/Journal of investigative dermatology” This study identified a high-risk allele in the PLCD1 gene associated with hereditary trichilemmal cyst formation, proposing a monoallelic two-hit mechanism as the underlying genetic pathogenesis.
10 citations
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July 1984 in “British Journal of Dermatology” In this study, the staining properties of two types of cysts, epidermal and pilar, were found to differ, supporting their origins from the epidermis and the trichilemmal hair follicle layer, respectively.
2 citations
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September 2021 in “Journal of Pathology of Nepal” This study found that cutaneous cysts most frequently appeared as epidermal cysts, with unusual locations posing diagnostic challenges that required histopathological analysis for definitive diagnosis.
2 citations
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June 2012 in “American Journal of Dermatopathology” This case study describes a rare cutaneous follicular hybrid cyst intimately associated with syringocystadenoma papilliferum, proposing a potential relationship with the infrainfundibulum based on keratin expression.
34 citations
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February 2012 in “American Journal of Dermatopathology” This study found that calretinin immunoreactivity may help identify the innermost cell layer of the outer root sheath in anagen hair follicles and certain cutaneous adnexal proliferations with follicular, sebaceous, and eccrine differentiation.
54 citations
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September 1999 in “PubMed” This study suggests that immunostaining for Keratin 15 may be a useful tool for differentiating between basal cell carcinoma and trichoepithelioma.
January 2009 in “Repositório Científico do Instituto Politécnico de Viseu (Instituto Politécnico de Viseu)” This case study found that a skin lesion in a Samoyed dog did not match any single known follicular cyst or neoplasm type described in the literature.
15 citations
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January 2008 in “Actas Dermo-Sifiliográficas” This study found that immunohistochemistry for calretinin may identify certain cutaneous adnexal tumors with follicular differentiation towards cells of the outer root sheath.