Proliferating trichilemmal tumor with a malignant spindle cell component

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.

Cutaneous adnexal carcinosarcoma: Immunohistochemical and molecular evidence of epithelial mesenchymal transition

Cutaneous carcinosarcomas are rare biphenotypic tumors that simultaneously show epithelial and mesenchymal differentiation. The most common carcinomatous components in skin carcinosarcomas are basal cell carcinoma and squamous cell carcinoma; adnexal carcinomas are rarely encountered. We report a case of an adnexal carcinoma with ductal and squamous differentiation and spindle cell component, which is interpreted as carcinosarcoma. Loss of immunohistochemical expression of E-cadherin and β-catenin detected in the sarcomatous component suggested epithelial mesenchymal transition (EMT). RNA sequencing analysis identified several gene mutations and alterations such as translocations and upregulations/downregulations, either shared by the two components of the tumor or differentially present in the carcinoma or the sarcoma parts. Thus, mutations in genes, such as TP53, were found in both components of the tumor while mutations in PDGFRA and RB1 (a pathogenic missense mutation) were exclusively present in the sarcomatous areas, further supporting EMT. EMT is a dynamic process by which tumors acquire mesenchymal phenotype while simultaneously losing epithelial properties. Although the pathways involved in EMT have been extensively studied, this phenomenon still needs to be investigated in cutaneous tumors of adnexal origin for a better understanding of their pathogenesis. These molecular changes may represent promising targets for personalized therapies.

Genomic landscape of a metastatic malignant proliferating tricholemmal tumor and its response to PI3K inhibition

Proliferating tricholemmal tumors (PTTs) are rare benign neoplasms that arise from the outer sheath of a hair follicle. Occasionally, these PTTs undergo malignant transformation to become malignant proliferating tricholemmal tumors (MPTTs). Little is known about the molecular alterations, malignant progression, and management of MPTTs. Here, we describe the case of a 58-year-old female that had a widely metastatic MPTT that harbored an activating PIK3CA mutation and was sensitive to the PI3K inhibitor, alpelisib (BYL719). We review the available literature on metastatic MPTT, detail the patient's course, and present a whole genome analysis of this rare tumor.

Fine-needle aspiration cytology in the diagnosis of malignant proliferating trichilemmal tumor: Report of a case and review of the literature

Malignant proliferating trichilemmal tumor is a rare cutaneous neoplasm derived from the outer root sheath of the hair follicle. Fine-needle aspiration cytology is being increasingly used in the investigation of primary and metastatic cutaneous tumors. However, there are few reports on the cytology of trichilemmal tumors in the literature. We describe the cytological features of this uncommon adnexal tumor presenting as a scalp mass in a 58-year-old woman. In view of its aggressive biological behavior, it is crucial for cytologists to be aware of this rare lesion and distinguish it from primary cutaneous squamous-cell carcinoma. The differences on fine-needle aspiration cytology can be subtle and pose problems in diagnosis.

Proliferating trichilemmal tumors: a review of the literature

BACKGROUND

Proliferating trichilemmal tumors (PTTs) are uncommon lesions whose histologic hallmark is the presence of trichilemmal keratinization. PTT is thought to originate from the trichilemmal cyst (TC) and have the potential for malignant transformation, at which point it is termed a malignant proliferating trichilemmal tumor (MPTT). These lesions may cause considerable morbidity and even mortality, and recurrence after simple local excision is common.

OBJECTIVE

The objective was to review the clinical presentation, histopathologic characteristics, malignant potential, and treatment options for PTT.

METHODS

The English literature was reviewed regarding PTT, TC, and MPTT.

RESULTS

PTT generally presents as a subepidermal tumor on the scalp in women over the age of 60. Histologic findings may be used to differentiate PTT from TC and MPTT. Complete surgical excision is recommended; additional radiotherapy and/or chemotherapy may be used for lesions with increased invasive potential.

CONCLUSION

Adequate treatment of PTT requires skilled histopathologic examination for proper diagnosis; histologic appearance may not correlate with clinical behavior. After surgical excision, long-term clinical follow-up for evidence of metastatic disease is judicious.

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.

Giant proliferating trichilemmal tumor of the gluteal region

BACKGROUND

Proliferating trichilemmal tumors are rare cutaneous neoplasms that show features of typical pilar cysts but also show extensive epithelial proliferation, variable cytologic atypia, and mitotic activity. Proliferating trichilemmal tumors are benign lesions; however, there are numerous reports of malignant proliferating trichilemmal tumors.

OBJECTIVE

We present a case of benign proliferating trichilemmal tumor of an 81-year-old woman that was located on the left superior gluteal region for 30 years.

METHODS

A tumor measuring 9 x 7 cm was surgically excised with a 1 cm conservative margin of normal tissue.

RESULTS

Based on the histopathologic findings of tumor, this case was diagnosed as proliferating trichilemmal tumor. The patient's condition was successfully treated with total excision.

CONCLUSIONS

Our case is an unusual presentation of proliferating trichilemmal tumor. Physicians should be aware of this entity while differentiating cutaneous tumor located on the gluteal region.

Cutaneous carcinosarcoma: adnexal vs. epidermal types define high- and low-risk tumors. Results of a meta-analysis

OBJECTIVE

We report four cases of cutaneous carcinosarcoma (CS) and perform a meta-analysis of the cutaneous CS literature.

RESULTS

CS occurred in elderly patients (mean of 80 years) on sun-damaged skin, and were keratotic papules of short duration. They did not recur after excision. CS exhibited basal cell carcinoma mixed with atypical fibroxanthoma cell populations. Immunophenotyping revealed vimentin+/keratin- spindle cells and vimentin-/keratin+ epithelial cells. Three cases exhibited p53 protein expression of both carcinomatous and sarcomatous components. Literature review identified 38 cases of cutaneous CS that could be broadly classified into two distinct groups. Epidermal-derived (basal or squamous cell carcinoma epithelial component) CS arose on the sun-damaged skin of the head and neck of elderly males (mean age 72 years) and had a 70% 5-year disease-free survival. In contrast, adnexal CS (spiradenocarcinoma, porocarcinoma, proliferating tricholemmal cystic carcinoma, or matrical carcinoma) occurred in younger patients (mean age 58 years), showed recent growth in a long-standing nodule and had a 25% 5-year disease-free survival. Age less than 65 years, recent growth, long-standing skin tumor, and tumor size greater than 2 cm significantly correlated with poor outcome.

CONCLUSIONS

Cutaneous CS is an aggressive skin cancer with high risk for advanced disease. Significant risk factors exist whose identification will allow for better management of CS patients.

Biphasic sarcomatoid basal cell carcinoma (carcinosarcoma): four cases with immunohistochemistry and review of the literature

BACKGROUND

Biphasic sarcomatoid carcinoma (BSC), or carcinosarcoma, is an uncommon biphasic neoplasm that has been reported in diverse anatomical sites. The tumor is composed of a malignant epithelial component intimately associated with a malignant mesenchymal component, which may be homologous or heterologous. Twenty-three cases of primary cutaneous BSC have been reported in the English literature. In only eight of these cases was basal cell carcinoma the epithelial component.

METHODS

We report a further four cases of primary cutaneous biphasic basal cell carcinoma, and include the clinical, histological and immunohistochemical features.

RESULTS

The four cases showed basal cell carcinoma associated with a pleomorphic sarcomatous stroma. In addition, myofibroblastic differentiation and foci of osteoid were present in one case, and leiomyosarcomatous areas in another. The epithelial components were positive for several epithelial markers. The mesenchymal components were positive for vimentin and CD99, and negative for epithelial markers. p53 was positive with equal intensity in both epithelial and mesenchymal components. A significantly worse outcome was observed in patients with tumors measuring 40 mm or more at excision.

CONCLUSIONS

The sarcomatous component of the tumor is best regarded as a metaplastic transformation of the carcinomatous component. These tumors are potentially aggressive if incompletely excised, and complete resection is recommended.