The molecular pathogenesis of Trichilemmal carcinoma

Excision of a large trichilemmal carcinoma of the back with staged reconstruction using biodegradable temporizing matrix (BTM): A case report

Trichilemmal carcinomas (TC) are rare skin malignancies that arise from the external root sheet of a hair follicle. Their incidence increases with advanced age and they most commonly occur on sun exposed skin or areas of significant hair growth. They vary significantly in size and appearance. Surgical excision is the most common treatment option. We report the case of a large trichilemmal carcinoma of the back occurring in a woman with poorly controlled diabetes mellitus. The lesion was excised resulting in a very large defect, which was reconstructed in a staged process using biodegradable temporising matrix (BTM) and split-skin grafting. There was 95 % graft take at first graft check and the wound was fully healed at 6 weeks post grafting. BTM, already an established adjunct in the reconstruction of burns, degloving injuries and soft tissue infections, provided an enhanced aesthetic outcome and successful wound healing in this complex skin lesion excision.

The Value of Ultrasound for Differentiating Trichilemmal Cysts From Epidermoid Cysts

OBJECTIVES

This study was aimed to evaluate the diagnostic performance of ultrasound (US) in differentiating trichilemmal cysts (TCs) from epidermoid cysts (ECs).

METHODS

Based on clinical and ultrasound features, a prediction model was established and validated. 164 cysts in the pilot cohort and another 69 in the validation cohort diagnosed with TCs or ECs histopathologically were evaluated. The same radiologist performed all ultrasound examinations.

RESULTS

For clinic features, TCs tended to occur in females compared with ECs (66.7 vs 28.5%; P < .001). In addition, TCs were prone to occur in the hairy area compared with ECs (77.8 vs 13.1%; P < .001). For ultrasound features, the internal hyperechogenicity and cystic change were more likely to appear in TCs in comparison with ECs (92.6 vs 25.5%; P < .001; 70.4 vs 23.4%; P < .001, respectively). Upon the features mentioned above, a prediction model was established with the areas under the receiver operating characteristic curves of 0.936 and 0.864 in the pilot and validation cohorts, respectively.

CONCLUSIONS

US is promising for differentiating TCs from ECs and is valuable for their clinical management.

Systematic analysis and case series of the diagnosis and management of trichilemmal carcinoma

Background

Trichilemmal carcinoma (TLC) is a rare malignant cutaneous adnexal neoplasm, with no relatively comprehensive research.

Objective

The aim of this study is to perform an updated statistical analysis so as to better understand TLC's epidemiology, clinical features, diagnosis, and treatment.

Methods

The diagnosis and treatment of three TLC cases in our department were summarized. Then, all TLC cases published in the literature were retrieved for a comprehensive analysis, followed by the analysis of global trends and regional distribution, demographic characteristics, clinical features, pathogenesis, histopathological features, and treatment and prognosis of TLC.

Results

Of the 231 cases, the incidence of TLC has shown an upward trend recently, especially in China, in Asia. The susceptible population is men aged 60-80 and women over 80, and the most prone location is head and neck. The phenotype of TLC is not always typical and may be misdiagnosed because of the coexistence of other diseases. There is a linear relationship between the diameter and its duration or thickness. UV, locally present skin lesions, trauma, scarring, organ transplantation, and genetic disorders may trigger the occurrence of TLC. Periodic acid-Schiff staining and CD34, but not Epithelial Membrane Antigen (EMA), were helpful in the diagnosis of TLC. Although effective, surgical excision and Mohs micrographic surgery need further improvement to reduce recurrence of TLC. Carcinoma history is an independent risk factor for TLC recurrence.

Limitations

The limitation of this study is the lack of randomized controlled trial on TLC treatment and recurrence.

Conclusion

TLC has the possibility of invasive growth and recurrence, especially in patients with longer duration and carcinoma history.

Axillary lymph node dissection combined with radiotherapy for trichilemmal carcinoma with giant lymph node metastasis: A case report

Background

Trichilemmal carcinoma (TC) is a rare malignancy with a poor outcome if local recurrence and distant metastasis occur. There is no treatment strategy for such a disease.

Case presentation

We reported a complicated case of TC in the right lower abdomen with ipsilateral axillary and inguinal lymph node metastases. After surgery and radiotherapy, there has been no recurrence or metastasis in the follow-up to date.

Conclusion

We believe that even though considered a tumor of low malignant potential, TC still has the risk of recurrence and metastasis, and the lymph node status should be identified if a high suspicion or diagnosis is made. Regional lymph node dissection followed by local radiotherapy is recommended as the optimal treatment strategy for patients with lymph node metastases of TC. Screening for metastasis and close follow-up are indispensable for improving prognosis.

Corneal Perforation Caused by Eyelid Margin Trichilemmal Carcinoma: A Case Report and Review of Literature

Background

Trichilemmal carcinoma (TLC) is a rare malignant adnexal tumor most commonly found in the elderly, usually affecting the scalp, eyelids, neck and face. Here, we first reported a rare case of corneal perforation caused by eyelid margin TLC.

Case Presentation

A 68-year-old female presented with 2 months history of unprovoked redness, pain and blurred vision in the left eye. On slit-lamp examination, a 1 × 2 mm sized aseptic corneal perforation embedded by iris prolapsed was noted. Upon detailed case investigation, we speculated that the severe meibomian gland dysfunction (MGD) and subsequent Blepharokeratoconjunctivitis (BKC) could have led to corneal perforation. The patient underwent penetrating keratoplasty to prevent ulcer enlargement and infection. However, several tiny nodules gradually developed on the eyelid margin postoperatively, accompaniedby with bleeding, burst and madarosis postoperatiely. Subsequently, biopsy revealed the growth of TLC on the eyelid margin, and lesionectomy was immediately conducted During the 1-year follow-up period, no local recurrence or metastasis was observed.

Conclusions

To date, there has not been any report of corneal perforation caused by eyelid margin TLC. Consideration of the clinical presentation, feature and histopathologist will be benefit for the dignoses and treatment of TLC. Ensuring a smooth eyelid margin by total excision of TLC and consistent followup of patient will avoid recurrence.

Treatment of Malignant Adnexal Tumors of the Skin: A 12-Year Perspective

Malignant adnexal cancers of the skin—extremely rare neoplasms—are mostly reported as non-symptomatic, slow-growing nodules. These carcinomas occur mainly in the middle-aged (50–60 years of age); they are mostly localized on the upper part of the body and are locally aggressive, infiltrate surrounding tissue, and metastasize to regional lymph nodes. The patients’ outcomes depend on multiple prognostic factors, including the size of the primary tumor and its mitotic count. Surgical resection of the primary tumor with or without regional lymph nodes is the treatment method of choice; however, due to aggressive tumor behavior, perioperative treatment may be considered. The role and efficacy of radiotherapy in the treatment of skin adnexal malignancies are not yet fully defined. Some authors suggest that adjuvant radiotherapy may be considered in locally advanced and regional disease. The aim of this study was to evaluate treatment outcomes and assess the efficacy of combined therapy in patients with adnexal malignancies. Our analysis covered all cases of cutaneous adnexal tumor patients diagnosed and provided with multidisciplinary treatment with surgery and radiotherapy since the beginning of 2009.

Trichilemmal Carcinoma of the Scalp in a Young Female: A Case Report

Trichilemmal carcinoma (TC) is a rare malignant cutaneous adnexal neoplasm originating from the outer root sheath of hair follicles, which occurs commonly in sun-exposed areas of the elderly. Here, we introduce a case of a 24-year-old woman with TC on her scalp.

Molecular pathology of skin adnexal tumours

AIMS

Tumours of the cutaneous adnexa arise from, or differentiate towards, structures in normal skin such as hair follicles, sweat ducts/glands, sebaceous glands or a combination of these elements. This class of neoplasms includes benign tumours and highly aggressive carcinomas. Adnexal tumours often present as solitary sporadic lesions, but can herald the presence of an inherited tumour syndrome such as Muir-Torre syndrome, Cowden syndrome or CYLD cutaneous syndrome. In contrast to squamous cell carcinoma and basal cell carcinoma, molecular changes in adnexal neoplasia have been poorly characterised and there are few published reviews on the current state of knowledge.

METHODS AND RESULTS

We reviewed findings in peer-reviewed literature on molecular investigations of cutaneous adnexal tumours published to June 2021.

CONCLUSIONS

Recent discoveries have revealed diverse oncogenic drivers and tumour suppressor alterations in this class of tumours, implicating pathways including Ras/MAPK, PI3K, YAP/TAZ, beta-catenin and nuclear factor kappa B (NF-κB). These observations have identified novel markers, such as NUT for poroma and porocarcinoma and PLAG1 for mixed tumours. Here, we provide a comprehensive overview and update of the molecular findings associated with adnexal tumours of the skin.

Update on Molecular Genetic Alterations of Cutaneous Adnexal Neoplasms

Cutaneous adnexal tumors recapitulate follicular, sweat gland, and/or sebaceous epithelia, and range from benign tumors to aggressive carcinomas. Adnexal tumors can be hallmarks for inherited tumor syndromes. Oncogenic drivers of adnexal neoplasms modulate intracellular pathways including mitogen-activated protein kinase, phosphoinositide-3-kinase, Wnt/β-catenin, Hedgehog, nuclear factor κB, and Hippo intracellular signaling pathways, representing potential therapeutic targets. Malignant progression can be associated with tumor suppressor loss, especially TP53. Molecular alterations drive expression of specific diagnostic markers, such as CDX2 and LEF1 in pilomatricomas/pilomatrical carcinomas, and NUT in poromas/porocarcinomas. In these ways, improved understanding of molecular alterations promises to advance diagnostic, prognostic, and therapeutic possibilities for adnexal tumors.

Current Diagnosis and Treatment Options for Cutaneous Adnexal Neoplasms with Follicular Differentiation

Neoplasms derived from follicular tissue are extremely rare. Clinically, they are reported as non-symptomatic, slow-growing nodules. These lesions are mainly benign, but the malignant type can occur. Mainly middle-aged people (50-60 years of age) are affected. These carcinomas are mainly localized on the head and neck or torso. They can be locally aggressive and infiltrate surrounding tissue and metastasize to regional lymph nodes. In the minority of cases, distant metastases are diagnosed. Quick and relevant diagnosis is the basis of a treatment for all types of tumors. The patient's life expectancy depends on multiple prognostic factors, including the primary tumor size and its mitotic count. Patients should be referred to a specialized skin cancer center to receive optimal multidisciplinary treatment. This article tries to summarize all the information that is currently available about pathogenesis, diagnosis, and treatment methods of follicular tumors.