Proliferating trichilemmal cyst: report of two cases, one benign and the other malignant

Benign proliferating pilar tumor excised with Slow Mohs surgery: A case report

Proliferating pilar tumors are rare, benign, exophytic neoplasms, which can closely resemble a squamous cell carcinoma. We describe a patient with a large benign exophytic tumor on the scalp that had been slowly growing over 10 years. While this class of benign follicular tumors is rare, the standard of care is typically excision with clear histologic margins. In this case, this large scalp tumor was surgically excised with clear margins/permanent section margin control using "Slow Mohs" technique, with subsequent repair using a skin substitute dressing, followed by a delayed skin graft.

A malignant proliferating trichilemmal cyst arising on the elbow of a man: A case report and review of the literature

INTRODUCTION

Trichilemmal cysts (TCs) are common benign cysts that form from the hair follicles in the skin. Proliferating trichilemmal cysts (PTCs) are rare types of TCs characterized by rapid cellular proliferation. Malignant transformation of PTC (MPTC) is a rare adnexal tumor that account for <0.1% of all skin cancers. TCs and PTCs are benign tumors; however, MPTCs grow rapidly and are prone to metastasis.

CASE PRESENTATION

A 77-year-old man was referred to our hospital with a solitary pinkish mass on his left elbow. Trichilemmal carcinoma arising from a PTC was confirmed through excisional biopsy, and wide excision was performed. One month postoperatively, a cystic mass was observed and was suspected to have local recurrence; however, bursitis was confirmed after excisional biopsy. After 1 year of follow-up, the patient maintained an improvement without recurrence or any other surgical complications.

CONCLUSIONS

In addition to being a very rare disease, MTPC occurred in the elbow of a man who does not fit the general etiology; therefore, it is considered an interesting case, and we report this case for academic contribution.

Malignant Proliferating Trichilemmal Tumor of the Scalp: A Systematic Review

OBJECTIVES

Malignant proliferating trichilemmal tumors of the scalp can exhibit aggressive presentation and recurrences. Our objective was to perform an evidence-based systematic review evaluating clinical presentation, tumor characteristics, and treatment modalities used to determine which treatment strategies had the best outcomes.

METHODS

The databases PubMed, Embase, and Cochrane Library were searched for relevant literature by the authors. Patient demographics, imaging, treatments, and other clinical characteristics were obtained. The results were reported using the Preferred Reporting Systems for Systematic Reviews and Meta-Analysis guidelines.

RESULTS

Thirty-nine studies with a total of 65 patients were identified. The most common presentation was a history of slow-growing, painless swollen mass on the scalp. In total, 10 patients (15.4%) presented with spread to the regional lymph nodes and 6 (9.2%) additional patients presented with metastasis to distant locations. In total, 61 patients (93.8%) underwent surgery. Various chemotherapy and radiation therapy regimens were used. Of the 45 cases with documented follow-up, 11 (24.4%) patients had one or multiple instances of local, lymph node or metastatic tumor recurrence.

CONCLUSIONS

Surgery is favored, and the exact approach should be based on clinical judgment. However, Mohs micrographic surgery should strongly be considered because of its superior margin control against such an invasive tumor. Radiotherapy and chemotherapy have been used as adjuvant therapy in aggressive cases or recurrence. Patients should be followed closely and examined often to frequently assess recurrence or metastasis. Randomized controlled trials are needed to further clarify these findings.

Surgical treatment of rare giant malignant tumors of the scalp: A report of 3 cases with different tumor types

The scalp is the most frequent site of occurrence of malignant tumors. As an area that is generally neglected by the patient and not closely monitored during physical examinations, scalp tumors can go unnoticed until they become malignant. The present study reports 3 cases of rare giant malignant tumors of the scalp, namely a peripheral nerve sheath tumor, a fibrous tumor and a malignant proliferating trichilemmal tumor, that were treated at The First Bethune Hospital of Jilin University (Changchun, China). Vascularized free anterolateral thigh flap surgery was performed in 2 of the 3 cases. A local flap repair was applied to the third case. The implanted skin grafts remained viable post-operatively and wound repair was uneventful. No signs of malignancy were detected on the edge of the pathological section upon closer pathological examination. In the follow-up period, no recurrence was detected in any of the cases.

Proliferating trichilemmal cyst: the value of ki67 immunostaining

Background:

A proliferating trichilemmal cyst (PTC) is an uncommon, rapidly-reproducing cutaneous epithelial cyst, differentiating from the isthmic portion of the outer hair root sheath. It is usually described as a benign tumor, but malignant transformation has been reported and is then denominated as a malignant proliferating trichilemmal tumor. Ki67 immunostaining has been used as a methodology for the evaluation of tumor grade in other tumors, due to its distinctive reaction patterns which exclusively involve proliferating cells.

Objectives:

(1) To report the incidence of cases of PTCs in a General Hospital during a 12 years period. (2) To determine the expression of ki67 using immunohistochemical staining. (3) To correlate ki67 reaction patterns with clinical prognosis.

Materials and Methods:

The dermatology department's files during a period of 12 years were reviewed; cases with a diagnosis of PTC were selected, and ki67 immunostaining was done when enough biological material was available.

Results:

A total of 15 cases with a diagnosis of PTC were identified. In 12 cases, ki67 immunostaining was carried out. In 9 of the 12 cases, ki67 was observed in the basal cells of the cystic epithelium, one case was moderately positive in palisading epithelial cells; in the other two cases ki67 immunostaining was negative. Clinical follow-up was done and revealed that no patient had local recurrence in 5 years after surgical removal of PTC. We therefore consider this immunostaining technique is probably correlated with low recurrence potential.

Morphological spectrum of pilar cysts

Background:

Cysts of the skin are one of the commonly excised specimens in the surgical outpatient department. A majority of them being clinically diagnosed as sebaceous cysts, their true nature is only discernible on histopathological examination. Closer examination of the type of keratinization involved will throw light into the exact nature of the cyst. Trichilemmal or Pilar cyst is one such entity, which presents in both a non-neoplastic and neoplastic form.

Aims:

The present retrospective observational study was undertaken to find out the incidence of these cysts in surgical pathology practice in a rural hospital and to enlist the various morphological forms that these cysts may take.

Materials and Methods:

The histopathology files were reviewed for a period of 6 years for cases coded as pilar cyst.

Results:

A total of eight cases (5.75%) were identified, which showed features of trichilemmal differentiation. A single case each of proliferating trichilemmal cyst and malignant proliferating trichilemmal tumors were noted. Most of the cases were seen among females on the scalp.

Conclusions:

Trichilemmal tumor is an uncommon histopathological entity. Many of these lesions may be mistakenly diagnosed due to lack of recognition of the unique type of keratinization.

MR Imaging Findings of Giant Trichilemmal Carcinoma on the Scalp. A Case Report

We describe the magnetic resonance imaging findings of a huge trichilemmal carcinoma (TLC) on the parietal and occipital region of the scalp in one patient. Our aim is to discuss the clinical, radiologic, and pathologic features of scalp TLC and to review relevant literature regarding this tumor. One patient with recent rapid tumor growth in the parietal and occipital region of the scalp underwent MR studies and subtotal resection. The tumor was seen as a poorly marginated and lobulated soft-tissue mass with isointense signal on T1-weighted images and hyperintense signal on T2-weighted images. Necrosis and ulceration were also found on the tumor surface. The TLC has been massively invading the nearby skull, meninges, brain tissue, and superior sagittal sinus. After exhibiting contrast, the tumor showed significant enhancement, with small portions remaining unenhanced. Subtotal excision of the mass and reconstruction of the scalp were performed. Microscopically, the mass was composed of trabecular growth of tumor cells with clear cytoplasm, prominent nucleoli, frequent mitoses, and foci of trichilemmal keratinization. Tumor on the scalp with heterogeneous, mixed signals on T2-weighted images, significant enhancement of solid portion, and local infiltration accompanied by surface deep ulceration may indicate a TLC. Wide surgical excision with tumor-free margins remains the best choice for treatment.

Differential diagnosis of soft scalp lumps

A 56-year-old man presented with a painless cyst on the top of his head which has been increasing in size in the last 6 months. Due to his learning disability, he could not be dissuaded from his belief that the lump was a sign of brain prolapse which led to increasing agitation in the next 2 weeks. A provisional diagnosis of benign lipoma was made and prompt excision was performed in his best interests. The lesion was more cystic and fluctuant than that of a lipoma and hence it was sent for histological diagnosis. The report came back as a trichilemmal cyst with no signs of proliferation. Cosmetic outcome was reasonable at follow-up after 3 months. The patient was scheduled for regular review every 6 months.

Posttraumatic proliferating trichilemmal tumour on the frontal region of the scalp: a case report

Introduction

Proliferating trichilemmal tumour defined with more than one terms by many author, after well documentated series reported as "proliferating epidermoid cysts" by Wilson-Jones, firstly in 1966. They are rare, slowly growing, lobular masses inherited autosomal dominantly and localized on scalps of older women and believed to arising as a complication of a trauma and inflammation and effect 5-10% of people.

Case presentation

We intented to present the case of a 62 years old Turkish woman with a history of slowly growing scalp mass after the trauma, especially during last 15 years. After surgical evaluation, histopathological slides exhibited the characteristic structures of proliferating trichilemmal tumour. The patient was lost to follow-up and no recurrens or distance metastasis detected during 40 months follow-up.

Conclusion

In our opinion, widely surgical excision with long-term surveillance is the best choice for both diagnosis and treatment still today.

Mohs' Micrographic Surgery of a Proliferating Trichilemmal Tumor in a Young Black Man

BACKGROUND

Proliferating trichilemmal tumor is an uncommon tumor of the follicular isthmus of the hair follicle. It usually presents as a solitary nodule on the scalp of older white women. Although these lesions typically behave in a benign fashion, recurrences and metastasis after local excision have been reported. Mohs' micrographic surgery has been effectively used to treat adnexal neoplasms.

OBJECTIVE

To report a case of a proliferating trichilemmal tumor in a young black man, which was excised using Mohs' micrographic surgery.

METHODS

Case report and review of the literature.

RESULTS

Mohs' micrographic surgery demonstrated an irregular extension of the tumor beyond a 1 cm surgical margin.

CONCLUSIONS

Proliferating trichilemmal tumors should be considered in the differential diagnosis of cutaneous neoplasms on the scalp in persons of any age (with the possible exception of infants and children), sex, or race. Mohs' micrographic surgery may be considered an optimal treatment option for proliferating trichilemmal tumors because these lesions may have an infiltrative component that may not be clinically apparent.