The molecular pathogenesis of Trichilemmal carcinoma.

BACKGROUND: Trichilemmal carcinoma (TC) is an extremely rare hair follicle tumor. We aimed to explore the genetic abnormalities involved in TC to gain insight into its molecular pathogenesis. METHODS: Data from patients diagnosed with TC within a 12-year period were retrospectively reviewed. Genomic DNA isolated from a formalin-fixed paraffin-embedded (FFPE) tumor tissue block was sequenced and explored for a panel of cancer genes. RESULTS: DNA was extracted from the FFPE tissue of four patients (50% female; mean age, 51.5 years) diagnosed with TC for analysis. The tumor was located in the head and neck of three patients and in the shoulder of one patient. TP53 mutations (p.Arg213*, p.Arg249Trp, and p.Arg248Gln) were found in three patients. Fusions previously identified in melanoma were detected in two patients (TACC3-FGFR3 and ROS1-GOPC fusions). Other mutations found included NF1-truncating mutation (Arg1362*), NRAS mutation (p.Gln61Lys), TOP1 amplification, and PTEN deletion. Overall, genetic changes found in TC resemble that of other skin cancers, suggesting similar pathogenesis. All patients with TP53 mutations had aggressive clinical course, two who died (OS 93 and 36 months), and one who experienced recurrent relapse. CONCLUSIONS: We reported the genomic variations found in TC, which may give insight into the molecular pathogenesis. Overall, genetic changes found in TC resembled that of other skin cancers, suggesting similar pathogenesis. TP53 mutations was were identified in patients who had an aggressive clinical course. Genetic alterations identified may further suggest the potential treatment options of TC.

[Trichilemmal carcinoma in a patient with squamous cell skin cancer]. / Trikholemmal'naia kartsinoma u patsienta s ploskokletochnym rakom kozhi.

Trichilemmal carcinoma is a rare skin tumor that mainly occurs in the elderly (mean age, 71 years) and is localized in the repeatedly sun-exposed areas, most commonly on the face, scalp, neck, and dorsa of the hands. Its differential diagnosis is made with squamous cell skin cancer, clear-cell porocarcinoma, hidradenocarcinoma, and melanoma. The prognosis of trichilemmal carcinoma is most favorable than that of other skin tumors during radical removal. The paper describes a case of an 80-year-old man with long-standing trichilemmal carcinoma of the skin in the area of the shoulder joint, which is concurrent with squamous cell cancer in another area of the skin.

Malignant hair follicle tumors of the periorbital region: A review of literature and suggestion of a management guideline.

Malignant hair follicle tumors are rare skin adnexal malignancies that have a predilection for the head and neck region. They can be categorized into a number of different subtypes. Histologically, they are distinct from their benign counterpart. To the best of our knowledge, there is no extensive review of these malignancies, especially in the periorbital region. We aim to provide a literature review and a guideline for management of these malignant tumors in the periorbital region. Database from Medline, PubMed, Embase, and Google Scholar were consulted. A total of 16 cases from the literature on hair follicle malignancies in the periorbital region were included in this review. The clinical presentations, diagnostic patterns, investigations used, and best management approach of these tumors are discussed. The American Joint Committee on Cancer (AJCC) 7(th) edition carcinoma of the eyelid staging system was used to describe their behaviors. We recommend wide excision surgery and a close follow-up for these tumors. Tumors presenting with a late stage require work-up for distant metastasis and consideration for exenteration procedures. The role of radiotherapy and chemotherapy in this context is still uncertain.

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.

A Rare Case of Trichilemmal Carcinoma of the Scalp.

Trichilemmal carcinoma (TC) is a rare, low-grade, malignant adnexal tumor. It is usually less than 3 cm long and arises from the external root sheath of the hair follicle, most commonly in sun-exposed areas of the body. The treatment of choice is wide local excision with tumor-free margins. We present an 88-year-old male patient who presented with an incidental large, dry, fumigating mass on his scalp for a one-year duration requiring surgical excision. The mass, initially thought to be a benign sebaceous cyst, was a 12-cm trichilemmal carcinoma diagnosed based on the histopathologic features of the mass. The specimen was composed of keratinaceous material and necrotic debris. The viable tumor was consistent with atypical squamous proliferation. The mass was fully excised down to the scalp on the first encounter, leaving no further tissue to excise. The patient's scalp site remained clean and without bleeding or recurrence. Currently, there is an increasing incidence of trichilemmal carcinoma. The pathophysiology of this disease is still unclear. The radiation from the sun is one of the factors that causes the growth of the lesions due to its location and distribution. Trichilemmal cysts can also transform into malignant trichilemmal carcinomas due to the p53 deletion. TC has a non-aggressive course despite its aggressive histology. The prognosis is generally good as it has low metastatic potential, like cutaneous squamous cell carcinoma. However, TC with metastasis has a poor prognosis, and there is no consensus yet on treatment. For non-metastatic TC, simple surgical excision with adequate (0.5-1 cm) margins is an effective treatment. Different studies use different margins, and there is no consensus on the measurement for margin excision. Regular follow-up is recommended, but further studies regarding follow-up schedules are needed. Furthermore, despite the common use of chemotherapy in cases of malignant TC, only a limited number of studies have explored this treatment approach. Given the increasing incidence of the disease, we highly recommend more research to address this knowledge gap.

Trichilemmal carcinoma metastatic to parotid gland: First report of fine needle aspiration cytology features.

Trichilemmal carcinoma is a rare malignant cutaneous adnexal neoplasm arising from the outer root sheath of the hair follicle. Majority of cases occur on sun-exposed sites such as the face, scalp and neck, making them easily amenable to being biopsied and subjected to histological examination for definitive diagnosis. Thus, cytological features of trichilemmal carcinoma have not been described till date. Trichilemmal carcinoma is a low-grade malignancy, albeit with potential to metastasize to regional lymph nodes and distant sites. We report the case of trichilemmal carcinoma of scalp that metastasized to cervical lymph nodes and parotid gland and underwent fine-needle aspiration cytology (FNAC) from the parotid lesion. The aspirate showed tightly cohesive cell clusters with sharp borders. Tumour cells ranged from basaloid with scant cytoplasm to those with abundant cytoplasm. Nuclei were vesicular, with inconspicuous to prominent nuclei. Intercellular bridges, masses of keratin, and fragments of desmoplastic stroma were present, closely recapitulating histological features of trichilemmal carcinoma, which enabled diagnosis as metastasis. Cell block showed similar tumour fragments with evidence of differentiation towards outer root sheath. FNAC is the first-line investigation to obtain a tissue diagnosis of masses in the head and neck region. Although rarely encountered, the lack of knowledge of cytological features of trichilemmal carcinoma may hamper its FNAC diagnosis at metastatic sites. When intraparotid metastases occur, they may be mistaken as primary salivary gland carcinoma. Thus, awareness of the cytological features of this tumour must be raised among cytopathologists to enable accurate diagnosis and further management.

Successful treatment of trichilemmal carcinoma with distant metastasis using pembrolizumab: a case report and review.

Trichilemmal carcinoma (TC) is a rare, malignant cutaneous adnexal tumor. TC often has nonspecific clinical manifestations and its aggressive nature is frequently overlooked. Metastasis of TC is rarely reported and there is no standard treatment for recurrent or metastatic TC. We report a complicated case of TC arising from the parotid gland with metastasis to cervical lymph nodes. The tumor progressed after multiple surgeries, radiation and chemotherapy. Finally, the patient achieved good response and disease control with pembrolizumab, an immune checkpoint inhibitor targeting programmed cell death protein-1. Currently, the patient has received 19 cycles of pembrolizumab and the disease remains well controlled. This represents the first reported use of immune checkpoint blockade to treat TC.

This paper discusses a rare form of skin cancer called trichilemmal carcinoma (TC) and presents a distant metastasis TC case. The patient was treated with an immunotherapy called pembrolizumab and after 19 courses of treatment, the tumor was significantly reduced and the symptoms were relieved. This case report is the first recorded case study of pembrolizumab for the treatment of TC and provides a new approach to the treatment of challenging malignancies.

The Incidental Finding of Trichilemmal Cyst in a Patient With Acute Kidney Injury.

This case highlights the importance of thorough clinical examinations from head to toe and the early diagnosis of trichilemmal cysts. We present a case of an incidentally discovered trichilemmal cyst in a 72-year-old patient who presented with acute kidney injury secondary to a urinary tract infection. In rare instances, these cysts can transform into malignant lesions. Therefore, clinicians should be aware of the potential for malignancy when diagnosing and managing trichilemmal cysts.

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.

Association of trichilemmal and basal cell carcinomas: a case report.

Proliferating trichilemmal tumor (PTT) is a benign tumor arising from the isthmic portion of the hair follicle. Malignant transformation in PPT is very rare and unusual. Indeed, only about sixty well-documented cases have been found in the English literature. We present here the case of a 72-year-old patient with an exceptional combination of malignant trichilemmal carcinoma and basal cell carcinoma, occurring on actinic keratosis lesions. The aim of this work is to describe the diagnostic and therapeutic modalities of this association which is exceptional.

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.

Nodular Hidradenocarcinoma, Trichelemmal Carcinoma and Squamous Cell Carcinoma with Clear Cell Changes: Pitfalls of Biopsy Diagnosis of Skin and Adnexal Tumours.

Skin and Adnexal tumours are a group of benign and malignant tumours whose basic diagnosis relies on histopathology. A single tumour may show more than 1 appendageal differentiation. Morphologic distinction between benign and its malignant counterpart is of utmost importance as it affects the treatment and prognosis of patient. We have described 3 cases who presented in our university hospital, in which final resection pathological diagnosis differed from initial core biopsy interpretation. The authors have made an attempt to provide a brief overview of diagnostic overlap existing between nodular hidradenocarcinoma and tumours of clear cell histology. Salient morphologic features differentiating cylindroma or trichilemmal carcinoma from squamous cell carcinoma have also been discussed. Final diagnosis is paramount for adjuvant management and prognostication of the patient in a clinical setting.

Trichilemmal carcinoma of the axilla with regional lymph nodes metastasis: A case report.

INTRODUCTION AND IMPORTANCE: Trichilemmal carcinoma is a rare malignant cutaneous adnexal neoplasm of hair follicles originating from the external root sheath epithelium. The diagnosis is rarely made clinically and is still challenging for an experienced pathologist. AIM: To report a rare case of trichilemmal carcinoma presenting as a right axillary mass with regional lymph nodes metastasis and was treated with wide local excision in the General Surgery Department Jordanian Royal Medical Services (JRMS), Jordan. CASE PRESENTATION: A 45-year-old presented with a right axillary mass of six-month duration. Physical examination revealed a hyperemic, thickened skin of both armpits with a palpable 5-cm mass in the right axilla. He underwent an excisional biopsy of the right mass. Histopathologic examination revealed a malignant adnexal skin tumour with foci of trichilemmal-type keratinisation. It was excised with adequate margins. CLINICAL DISCUSSION: Trichilemmal carcinoma usually occurs on the forehead, scalp, neck, back of hands and trunk. These neoplasms are rare lesions presenting as locally aggressive, low-grade carcinomas and have the potential for nodal involvement and distant metastasis. Therefore, the establishment of a correct diagnosis is vital to guide the treatment plan. Wide excision with adequate tumour-free margins is considered a curative treatment and offers a successful outcome. CONCLUSION: Malignant cutaneous adnexal tumours are one of the most challenging subjects of dermatopathology. Surgical excision is always required to establish a definitive diagnosis and differentiation subtypes. Trichilemmal carcinoma is a relatively rare tumour, mainly when located in the axilla.

Huge Trichilemmal Carcinoma With Metastasis Presenting With Two Distinct Histological Morphologies: A Case Report.

BACKGROUND: Trichilemmal carcinoma (TC) is a rare malignancy of cutaneous adnexal carcinoma, with only 136 cases reported in the literature to date. It usually has an indolent course and benign clinical evolution, and only four cases with regional and distant metastasis have been reported. Tumor cells present with the characteristics of trichilemmal differentiation on both histological and immunohistological examination. CASE PRESENTATION: We report a case of TC on the scalp with an aggressive course and metastasis to the ipsilateral neck. Moreover, the lesions presented with two distinct histological morphologies. CONCLUSION: Despite an indolent course and benign clinical evolution, TC has the potential for local invasion and recurrence, which implies that accurate early diagnosis and careful follow-up are very important for these patients. More than one specimen should be obtained for histopathological examinations when the lesion is very large and characterized by different morphologies.

A Rare Case of Trichilemmal Carcinoma: Histology and Management.

Trichilemmal carcinoma (TC) is a rare cutaneous tumor thought to be derived from the follicular outer root sheath (ORS). It often manifests as a nondescript skin-colored or pink papule on the hair-bearing, sun-exposed anatomic sites of elderly patients. Trichilemmal carcinoma shows many histologic features reminiscent of follicular ORS-notably, its glycogen-rich clear cells, trichilemmal keratinization, and similar immunostaining profile. Historically, it has been described as following a relatively indolent clinical course, but cases of recurrence, local aggression, and distant metastases have recently been elucidated. Here, we report the case of a 66-year-old male patient who presented with an asymptomatic, erythematous plaque on his neck; biopsy confirmed a diagnosis of TC. The patient deferred Mohs micrographic surgery in favor of wide local excision and was treated successfully with 3-mm margins. Salient histopathologic features, treatment modalities, and management recommendations are discussed.

Trichilemmal carcinoma in an unexposed area of the nose: A case report.

INTRODUCTION: Trichilemmal carcinoma (TC) is a rare, low-grade, cutaneous malignant lesion that originates from hair follicle cells. It usually occurs in photo-exposed areas, especially on the face, scalp, neck, and dorsal part of the hand. We report a case of an adult female with TC in an unexposed area of the nose, which completely obstructed the right nasal cavity. CASE PRESENTATION: An 82-year-old female presented with TC in a non-sun-exposed area of the nasal cavity, which grew progressively over one year and caused nasal obstruction. The mass had dimensions of 15cm × 8cm, and it was removed surgically with a wide and deep excision. Histopathological examination confirmed the diagnosis of TC. A follow-up at three years post-surgery revealed no signs of recurrence. CONCLUSION: Surgical excision with wide margins improved the treatment outcome by preventing local recurrence and providing satisfying cosmetic results.

Trichilemmal Carcinoma of Scalp Masquerading as Squamous Cell Carcinoma: A Report of a Rare Case with Histogenesis and Literature Review.

Trichilemmal carcinoma is a rare malignant adnexal neoplasm of follicular type usually seen over the sun-exposed areas of elderly people. We present a report of a 60-year-old male with ulceroproliferative lesion over the occipital region of the scalp for 2 months, clinically diagnosed as squamous cell carcinoma. A wide local excision was done, and histopathological examination showed atypical clear cells with abrupt keratinization. The histogenesis and other differential diagnoses are discussed.