Pilomatrix carcinoma: 12-year experience and review of the literature

Pilomatrix carcinoma unveiled: a systematic review of clinical characteristics, pathogenesis, diagnostic puzzles, and management strategies

Pilomatrix carcinoma (PC) is a rare malignant adnexal tumor originating from follicular matrix cells primarily impacting Caucasian males. This review provides a comprehensive analysis of scientific literature on PC through an exploration of 206 cases reported between 1980 and 2024. We discuss the epidemiology, clinical presentation, histopathology, and diagnostic challenges of PC, and explore various treatment methods for this rare malignancy as well as their associated outcomes. Wide local excision (WLE) is the most common management method, but Mohs micrographic surgery (MMS) may yield superior margin control and lower risk of recurrence and metastasis. Our findings underscore the need for further studies with thoroughly documented follow-up in order to create standardized evidence-based management guidelines and reduce risk of recurrence and metastasis of this rare and aggressive tumor.

Pilomatrix carcinoma of the lower extremity: A rare case report and literature review

INTRODUCTION

Pilomatrix carcinoma (PC) is a rare skin malignancy of the hair follicles matrix that tends to be locally aggressive with 10-16 % risk of metastasis mostly to the pulmonary and lymphatic system. There are no clear protocols for the management of PCs, however surgical intervention with clear margins has been highly considered in PC management to decrease risk of recurrence.

CASE PRESENTATION

A 40 year-old male patient presented to our clinic to evaluate an asymptomatic, slow-growing nodule localized on his left thigh. A CT scan revealed a well-defined, enhanced lesion with microcalcification. "En bloc" surgical resection of the lesion was performed and histopathology confirmed the diagnosis of pilomatrix carcinoma.

CLINICAL DISCUSSION

Given its rarity, there are no definitive guidelines regarding PC treatment. However, surgical intervention with clear margins including wide local excision or Mohs micrographic surgery has been highly considered. In our case, wide excision of the lesion with clear margins was performed with no evidence of recurrence one year later.

CONCLUSION

Given the local aggressive nature of PC, appropriate surgical intervention is essential in decreasing the risk of recurrence. Wide excision with clear margins has been proposed to decrease the risk of recurrence. Additionally, total-body skin examination should be done 2-3 times annually to evaluate for recurrence or metastasis.

Giant pilomatrix carcinoma of the scalp with intracranial extension: A case report

Key Clinical Message

A very rare skin cancer. Malignant variant of pilomatricoma. It is unique because of its highly aggressive behavior. Responds poorly to chemotherapy and radiotherapy. Treated with a wide surgical excision with safe margins.

Abstract

Pilomatrix carcinoma is uncommon and locally aggressive tumor of the hair follicle matrix. It is a malignant variant of pilomatricoma. If left untreated for a long time may attain massive size and has the potential for distant spread. Only few cases with brain extension have been reported in the literature. Diagnosis of these tumors is established by histopathology. Although pilomatrixoma and pilomatrix carcinoma are well-recognized lesions, clinically they are frequently misdiagnosed as other skin conditions. The tumors respond poorly to chemotherapy and radiotherapy. Thus, recommended treatment is a wide surgical excision with safe margins. Herein, we report the case of a 39-year-old African woman with pilomatrix carcinoma of the scalp eroding the skull bone with intracranial extension.

A Reddish Semitransparent Tumor in an Adolescent Girl

A previously healthy 16-year-old girl presented with a lesion on her right upper arm that initially started as a small cutaneous nodule without obvious triggers and gradually developed and enlarged to form a red-colored tumor with a hard nodule inside. What is your diagnosis?

A systematic review of Pilomatrix carcinoma arising from the previous scar site of Pilomatrixoma

Pilomatrix carcinoma is a rare tumor arising from the hair follicle matrix cells most commonly seen in the head and neck region. Also known as "calcified epithelial carcinoma of Melherbe," it was first reported in 1980 by Lopansri and Mihm. Since then till date to the best of our knowledge only around 125 cases were reported in literature, of which only 11 cases were reported to arise from histologically proven areas of previous pilomatrixoma which is the benign variant. One such case is being reported here along with the review of literature. A 50-year-old man presented with a swelling in the nape of his neck since 6 months, which was gradually increasing in size. He had a history of similar swelling at the same site 18 months back for which he underwent a surgery at a center outside. Final histopathology report was suggestive of pilomatrixoma with negative margin. Wide local excision of the tumor with 3 cm margin, placement of surgical clips followed by a primary closure was done. The final histopathology report is suggestive of pilomatrix carcinoma. The patient has no recurrence in 6 months follow-up. The differential diagnosis of pilomatrix carcinoma should be considered in cases of recurrent skin tumors. Wide local excision is the preferred treatment. Re-excision should be done in margin positive cases and cases where simple excision was done due to improper preoperative diagnosis. Due to the rarity of the disease, adjuvant treatment is not properly defined.

Giant Pilomatrix Carcinoma of the Thorax: An Uncommon and Clinically Misdiagnosed Tumor

Pilomatrix carcinoma is an unusual and aggressive malignant tumor deriving from follicular matrix cells and exhibiting a metastatic potential to lungs and regional lymph nodes in 10% of cases. We report the case of a 54-year-old male patient who presented with a biopsy-proven malignant pilomatrixoma of the thoracic region, which recurred multiple times after previous excisions. Due to the size of the tumor (28 by 22 cm), wide excision and axillary lymphadenectomy of levels I and II were performed, followed by reconstruction with a free deep inferior epigastric artery perforator flap and adjuvant radiotherapy. Owing to its rarity, this tumor can initially be misdiagnosed, resulting in delayed treatment and recurrences if inadequately excised. Also, large tumor size is correlated with a higher incidence of metastasis. High index of clinical suspicion and wide excision are recommended, along with the need of establishing oncological guidelines for better prognosis.

A Rapidly Growing Forearm Pilomatricoma in an Elderly Patient

Pilomatricoma is a benign skin tumor of epithelial hair matrix cells that typically presents as a solitary nodule on the head or upper trunk. It occurs most often in children and young adults. While considered uncommon in middle-aged and elderly patients, there are reports of elderly patients with histopathologically diagnosed pilomatricomas; however, these cases primarily occurred on the face. We present a case of an 88-year-old female with a history of non-melanoma skin cancer who presented with a new, rapidly enlarging, biopsy-proven pilomatricoma on the forearm. This case highlights a unique age of onset and location for this skin tumor, suggesting that pilomatricomas are not limited to children and young adults and should be considered in the differential diagnosis of rapidly growing skin lesions in elderly patients. Diagnosis should be confirmed with biopsy in elderly patients, as pilomatricomas may mimic malignant skin lesions.

An enlarging nodule on the vertex of scalp in an elderly man

A 79-year-old man presented with a crusty yellow lesion on his scalp. Histological examination revealed ulceration of the epidermis with an underlying mass in the dermis. Immunohistochemistry showed positivity for p63, and focal positivity for AE1/AE3, CK5/6 and EMA.

Pilomatrix Carcinoma: Report of Two Cases of the Head and Review of the Literature

BACKGROUND

Pilomatrix carcinoma (PC) is a rare skin tumor arising from hair follicle matrix cells. It is locally aggressive with a high rate of local recurrence after surgical excision. Few cases in the literature have been described and the management is not well defined.

OBJECTIVES

The aim of this study was to present two cases of PC located on the head and review the relevant literature about epidemiology, clinical and dermoscopic evaluation, characteristics of local and distant metastases, local recurrence rate and management of this rare skin tumor.

METHODS

We consulted databases from PubMed, Research Gate and Google Scholar, from January 2012 to November 2022. We reviewed the literature and reported two additional cases.

RESULTS

We selected 52 tumors in middle-aged to older patients located mostly on the head. Dermoscopy evaluation was rarely performed in the pre-operative diagnostic setting. The most definitive treatment was wide local excision, but local recurrences were common. In total, we observed 11 cases of recurrences and 9 patients with locoregional or distant metastases. Four patients received adjuvant radiotherapy, two patients needed chemotherapy and local cancer therapy and one patient received radiochemotherapy.

CONCLUSION

Our reports and the review of the literature can provide a better awareness and management of this rare tumor.

Auricular Malignant Proliferating Trichilemmal Tumor: A Case Report

Malignant proliferating trichilemmal tumor (MPTT) is a dermal adnexal tumor originated from the external root sheath of hair follicles. In this article, we reported a rare case of auricular MPTT in a 65-year-old male with gradually enlarging and bleeding mass on the right auricle measuring 30 × 20 × 12 mm in size and detailed the surgical strategy for therapy. The diagnosis of MPTT was established primarily by histopathological observation with abrupt keratinization, cytological atypia, abnormal mitoses, and infiltrating margins. Following extensive excision, no recurrence was noted for 14 months. We also discuss its clinicopathological features, differential diagnoses, and treatment methods and review the relevant literature in this regard.

Melanocytic matricoma with atypical features: A case of malignant melanocytic matricoma?

Melanocytic matricoma is a rarely reported, benign cutaneous adnexal neoplasm composed of epithelial cells exhibiting differentiation towards hair matrix as well as admixed, pigmented, dendritic melanocytes. The proposed malignant counterpart to melanocytic matricoma, malignant melanocytic matricoma (MMM), is even more rare. Here we report a case of a melanocytic matricoma with atypical features in a 92-year-old female with a 1.2-cm pigmented nodule on the right nasal sidewall. Histopathology revealed a well-circumscribed dermal tumor composed of atypical matrical cells with scattered aggregates of anucleate keratinocytes (ghost cells), prominent intratumoral pigment, numerous mitotic figures (88 mitosis/10 high-power field [HPF]), and intermixed dendritic melanocytes. A literature review was performed for MMM to determine if the current case fit diagnostic criteria for this entity. Including the current case, 12 cases of MMM were identified and analyzed to investigate common clinical and histopathologic features. MMM commonly occurred on the head and neck (7/12 cases) of older individuals (median age of 80) with a slight male predominance (male-to-female ratio of 3:1) and on histopathology presented as a multinodular dermal tumor composed of mitotically active (average mitotic rate of >50 mitoses/10 HPF) pleomorphic epithelial cells with foci of ghost cells. Dendritic melanocytes were found throughout the tumor lobules in all cases. Given that only two of 12 cases have exhibited locally aggressive behavior, further study is warranted to determine the true malignant potential of MMM.

Malignant proliferating trichilemmal tumor of the scalp: report of 4 cases and a short review of the literature

Malignant proliferating pilar tumors are very rare adnexial lesions that can be confused with other skin neoplasms. The authors present four patients with malignant proliferating trichilemmal tumors located on the scalp. A review of the literature search for malignant proliferating pilar tumors and treatments was performed.

FIGO Grade 3 Endometrioid Adenocarcinomas With Diffusely Aberrant β-Catenin Expression: An Aggressive Subset Resembling Cutaneous Pilomatrix Carcinomas

Uterine endometrioid adenocarcinomas are known for their morphologic plasticity. In addition to a multiplicity of metaplasias, uterine endometrioid adenocarcinomas may also undergo high-grade divergent differentiation in the form of high-grade neuroendocrine carcinoma, neuroectodermal differentiation or carcinosarcoma; others may dedifferentiate completely. Here we describe 5 cases of uterine endometrioid adenocarcinomas with high-grade divergent differentiation showing a striking morphologic and immunophenotypic resemblance to cutaneous pilomatrix carcinoma. Specifically, the high-grade component in all cases exhibited solid, basaloid morphology with conspicuous tumor cell necrosis and the presence of shadow cells, accompanied by diffusely aberrant (nuclear and cytoplasmic) β-catenin expression as well as variably diffuse CDX2 expression. In addition, the high-grade component in all cases showed loss of ER and PAX8 expression, retained MMR expression, wild-type p53 expression, patchy p16 expression, and diffusely positive cytokeratin expression (AE1/AE3 and CK7); at least focal neuroendocrine marker expression was present in all cases. CK20 was negative in all cases, with the exception of very focal staining in a single case (2% of tumor cells). All 5 of our tumors had at least a focal conventional FIGO grade 1 component. In all 4 cases tested, the low-grade component retained both PAX8 and ER expression and had, at best, focally aberrant β-catenin expression. Two of our cases had molecular analysis performed and both harbored mutations in exon 3 of CTNNB1 as expected; molecular analysis also revealed that both cases lacked POLE or TP53 mutations and showed no microsatellite instability. The tumors in this series were uniformly aggressive. Four of the 5 patients in our cohort had available follow-up information; of these, 3/4 died of their disease within 14 mo of diagnosis and the fourth patient had distant metastatic disease at presentation and is alive with disease 1 mo following diagnosis. The 1 patient without follow-up information also had distant metastatic disease at presentation and was lost to follow-up 17 mo later. The cases described in this series (1) represent a highly aggressive CTNNB1-mutated subset of the "no specific molecular profile" category of endometrioid adenocarcinomas; (2) illustrate a form of high-grade divergent differentiation resembling cutaneous pilomatrix carcinoma already described in carcinomas at other anatomic sites; and (3) underscore the difficulty in recognizing this phenotype at distant metastatic sites, which are frequent even at the time of presentation, given the consistent loss of ER and PAX8 expression and concurrent CDX2 expression.

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.

Malignant Pilomatricoma of the Lower Extremity: A Difficult and Rare Diagnosis

Malignant pilomatricoma is a rare cutaneous malignancy that is commonly found on the head and neck. We present a patient with malignant pilomatricoma of the lower extremity with intralesional calcification and giant cells, confirmed by histopathology. This patient’s case represents a clinically important variation of malignant pilomatricoma in an uncommon anatomical location.

CDX2 and SATB2 positivity in pilomatrix carcinoma: Avoiding an erroneous diagnosis of cutaneous metastasis of gastrointestinal origin

An 80-year-old female presented with a slowly growing 2-cm nodule on her shoulder over a 1-year period. Histopathologic sections of a biopsy specimen showed a multinodular, dermal-based basaloid tumor with areas of clear-cell change, stromal induction, as well as significant cytologic atypia and atypical mitotic activity. An initial investigation revealed positive staining of CDX2, a well-known marker of tumors of gastrointestinal origin. The case was referred to our dermatopathology service for consultation to determine if the lesion was in keeping with a cutaneous metastasis. On receipt of the case, an extended immunohistochemical panel was performed including SATB2, which displayed a similar pattern of staining as seen with CDX2. Although pathologists are most familiar with CDX2 and SATB2 as markers of gastrointestinal origin, the recent dermatopathology literature highlights that primary adnexal lesions of the skin also display positivity for CDX2 and can exhibit SATB2 positivity. We share a case of pilomatrix carcinoma with positive expression of nuclear CDX2 and SATB2, adding to the recent literature to (a) increase recognition of this staining pattern in hair follicle tumors, and (b) discuss briefly the shared molecular underpinnings in the tumorigenesis of gastrointestinal tumors and tumors of hair follicle origin that help clarify this underrecognized immunohistochemical pattern.

Pilomatrical carcinosarcoma in the very elderly: A case report

Pilomatrical carcinosarcomas are very rare tumors. To the best of our knowledge, only nine cases diagnosed with pilomatrical carcinosarcomas have been reported. The present study reported on a case of pilomatrical carcinosarcoma in the posterior part of the left auricle of a 100-year-old male patient. The tumor histologically comprised the following two components: Pilomatrical carcinoma and undifferentiated spindle cell sarcoma. The pilomatrical carcinoma comprised atypical basaloid cells and shadow cells. The basaloid cells had basophilic cytoplasm, clear nucleoli and deeply stained nuclear chromatin. The undifferentiated spindle cell sarcoma comprised atypical spindle cells. Both components contained numerous mitotic cells. The boundary area between the carcinoma and sarcoma smoothly transitioned into each other. The carcinoma cells and a portion of the sarcoma cells were positive for β-catenin in the cytoplasm with or without the nuclei. These results suggested that the two components developed from the same origin.

Ki67/MART1 and p63/SOX10 Dual Immunohistochemistry Allows a Correct Interpretation of the Melanocytic Component in the Diagnosis of Pigmented Pilomatricoma

Pilomatricoma is a relatively common benign cutaneous adnexal tumor and a well-recognized entity, while its pigmented variant is far less common and less reported. Its estimated frequency ranges from 11 to 24%, according to a limited number of published case series. This article describes the case of a 42-year-old man presenting a firm subcutaneous nodule of the periareolar region. Histopathologic examination revealed a cystic lesion composed of matrical and supramatrical cells accompanied by a foreign body granulomatous cell reaction. Interestingly, a hyperpigmented area with numerous hyperplastic melanocytes and few mitoses was detectable. In order to assess the cell lineage of the mitotically active component in the hyperpigmented area, double immunohistochemistry with Ki67/Mart1 and p63/SOX10 was performed. Pigmented pilomatricoma is an underrecognized, underreported variant, and double immunohistochemistry stain is an effective tool in providing the correct interpretation of the proliferative activity in the different cellular populations.

Pilomatrixcarcinoma of the Foot: A New Localization of an Extremely Rare Adnexal Tumour

Pilomatrixcarcinoma is a very rare follicular neoplasm that shows matrical differentiation. The majority of these lesions originate de novo, while only a few cases of transformation of pilomatricoma (calcifying epithelioma of Malherbe) have been described in the literature. The neoplasm affects mostly middle-aged males with a male-to-female ratio of 3-4:1. The most common localizations are the face, head, trunk and extremites, though there are a few reports of pilomatrixcarcinoma of the eyelid, eyebrow, axilla and clitorid. Here, we describe the first case of a pilomatrixcarcinoma on the anterolateral surface of the first toe of the left foot of an 83-year-old patient, which developed in less than six months and led to amputation of the distal phalanx. We report a brief review of the current literature with particular emphasis on histopathological features useful for diagnosis.

Common sense and tumor treatment. A case of pilomatrical carcinoma in a 21-year-old patient with surprisingly rapid tumor progression

Pilomatrical carcinoma is a rare tumor originating from skin appendages, usually occurring between the 5th and 7th decade of life. We present a case of an exceptionally young, 21-year-old patient with surprisingly rapid tumor progression and answer the question, what was the reason for such uncontrolled tumor growth. The main concern is the diagnostic challenge and a peculiar, one week race against time and tumor progression so that the least disfiguring surgery could be done.

18F-FDG PET/CT Findings in Metastatic Pilomatrix Carcinoma

We describe a rare case of metastatic pilomatrix carcinoma with distant metastases 10 months after diagnosis. A 37-year-old woman was diagnosed with pilomatrix carcinoma by excisional biopsy from the occipital region and referred to us for F-FDG PET/CT examinations at the time of diagnosis and 10 months after diagnosis. The first PET/CT did not show any pathological activity, whereas the second PET/CT showed multiple intensive F-FDG uptakes in the right lung parenchyma, right hemithorax pleura, liver, and bones.

Pilomatrix Carcinoma of the Antecubitum

We present the case of a 46-year-old male with atypically large left elbow pilomatrix carcinoma present for 10 years with emergent excision after developing life-threatening hemorrhage. Pilomatrix carcinoma is a dermal-based malignant tumor typically of the head and neck region. Histopathology shows islands of basaloid cells, shadow cells, and fibromyxoid fibroma. Reoccurrence is seen in 23% of cases on an average of six months after primary excision. The current standard of care is wide excision with close follow-up.

Pilomatrix carcinoma of the right postauricular region: A case report and literature review

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Pilomatrix carcinoma is a very rare locally aggressive tumor.

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A well-defined gold standard for surgical management has not been established.

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Currently wide local excision with safe margins is recommended.

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Regional lymph node dissection is performed when metastasis is suspected.

Introduction

Pilomatrix carcinoma is a rare aggressive tumor with a high rate of local recurrence after surgical excision. Diagnosis is made by histopathology and when discovered, wide local excision has been shown to have the best results.

Presentation of case

We report a case of a 74-year-old male incidentally found to have a large right postauricular mass and regional lymphadenopathy. The mass was biopsied and proven to be a malignant pilomatrixoma. Wide local excision and level II and III neck dissection with reconstruction using a right supraclavicular flap was performed.

Discussion

Pilomatrix carcinoma is a lesion first described in 1880 by Malherbe and Chenantais. It is unknown if these tumors arise de novo or arise through malignant transformation of a benign pilomatrixoma. There are similarities between the benign lesion and its malignant counterpart in terms of activating mutations in signaling pathways. A well-defined gold standard for surgical management has not been established, but currently wide local excision with safe margins is recommended along with regional lymph node dissection when metastasis is suspected. Currently, no chemotherapy regimen has been shown to be effective in local control or in preventing metastatic spread.

Conclusion

Pilomatrix carcinoma, given its aggressive nature, has a high propensity for recurrence after excision. It is important to perform wide local excision to avoid an incomplete resection and higher recurrence rates. Further studies will be needed to create a more defined standard of treatment and to evaluate the role of adjuvant chemotherapy and radiation therapy.