Pilomatricoma Research Articles

Endometrial Tumors with “Shadow Cells” Intimate a Neoplastic Potential for Morules or Their Progenitors in β-Catenin Mutated Endometrial Adenocarcinomas.

Background : Several features are shared by endometrial morules and pilomatrixoma-like endometrial carcinomas including CDX-2 and β-catenin nuclear staining, absence of p63 and p40 nuclear staining, and a unique form of endepithelial differentiation that produces so-called shadow cells. Both endometrial morules and pilomatrixoma-like endometrial carcinomas may be associated with low-grade endometrioid adenocarcinoma. Methods : We present 11 fully staged endometrioid endometrial adenocarcinomas that showed extrauterine metastases (Stages III and IV), morules, shadow cell differentiation, and nuclear β-catenin positive immunohistochemical staining (both in morules and in adjacent malignant glandular cells). Results : All intrauterine adenocarcinomas had at least focal components of grade 1 endometrial adenocarcinoma and morules and showed nuclear β-catenin immunostaining in morules and in adjacent malignant glandular cells. 10 cases were stages III and IV endometrial cancers, and one, initially diagnosed as grade 1 stage II endometrioid endometrial adenocarcinoma, rapidly recurred in the retroperitoneum as a nuclear β-catenin positive pilomatrixoma-like tumor without an obvious glandular component. Two positive lymph node dissections showed metastatic adenocarcinoma with malignant glands, morules and shadow cells. Five cases showed at least focal components of morphologically divergent high-grade tumor with foci resembling malignant pilomatrixoma. Extrauterine “shadow cell granulomas” were detected in 8 cases. Conclusion : Metastatic nuclear β-catenin positive endometrial adenocarcinomas with morules can metastasize and show pilomatrixoma-like tumor foci. This highlights the ability of these cancers to evolve into “other-than-glandular” carcinomas. Furthermore, because of their shadow cell features, we speculate that endometrial morules are not simply inert “epitumoral” elements; but that either they or the population of progenitor cells from which they eventuate harbors an abnormal β-catenin gene that may endow endometrial adenocarcinomas with morules the capacity for progressive, divergent differentiation into a higher-grade matrix-producing tumor.

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

Summary: 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 comparative study of pilomatricoma and epidermoid cyst with ultrasound

To explore and compare the ultrasonic (US) features of pilomatricoma (PM) and epidermoid cyst (EC) in the differential diagnosis and improve the accuracy of US diagnosis of PM. Three hundred and nine patients who underwent US examination before surgery with a histopathological diagnosis of PM or EC after surgery were analysed retrospectively. The patients were categorised into the training and validation sets according to the inspection times. Univariate analysis was undertaken on the US and clinical features of PM and statistically significant variables (p<0.05) were included in the multivariate logistic regression model to establish a diagnostic model. The results demonstrated that the multivariate logistic regression model for PM was statistically significant (p<0.001). The risk factors included posterior echo attenuation and hypoechoic halos (odds ratio [OR]=9.277, 10.254) and the protective factors included age, diameter thickness, and posterior echo enhancement (OR=0.936, 0.302, 0.156). The performance of the diagnostic model was tested using the training set (area under the receiver operating characteristic curve [AUC]=0.974, 95% confidence interval [CI]=0.955-0.994) and the validation set (AUC=0.967, 95% CI=0.926-1.000), which demonstrated good discriminant ability. The diagnostic accuracy for PM was higher than that for EC when the nodule is characterised by posterior echo attenuation, hypoechoic halos, smaller thickness, and younger age. The US diagnostic model developed may be used to guide the diagnosis of PM.

Cytological Diagnosis of Pilomatrixoma and its Diagnostic Pitfalls.

Pilomatrixoma (PMX) is a relatively uncommon benign cutaneous neoplasm arising from skin adnexa. It presents as a subcutaneous asymptomatic nodule mostly in the head and neck region and is frequently misdiagnosed by the clinicians. Although easily diagnosed on histopathology, the cytologic features of PMX are less distinctive, depending on the stage and evolution of disease and may mimic other benign or even malignant lesions. To study the cyto-morphological features of this uncommon neoplasm and identify its potential diagnostic pitfalls on fine needle aspiration cytology (FNAC). Archival records of histopathologically diagnosed Pilomatrixoma were analyzed during study period of 2.5 years. Clinical diagnosis, preoperative FNA characteristics, and histopathological details were studied in each case. Cytologic pitfalls resulting in misdiagnosis of PMX cases on FNAC were evaluated in discordant cases. The series showed male preponderance, with head and neck being the commonest site. Out of 21 histopathologically proven cases of PMX, cytological correlation was available in 18 cases. A correct cytologic diagnosis of PMX/adnexal tumor was rendered in 13 cases. Erroneous diagnosis was given in 5 cases mainly because of the predominance of one component over the other or non-representative-aspirated material. The present study highlights the importance of careful screening of FNAC smears keeping in mind the variability in the relevant cytologic features of PMX and creates awareness about the lesions that can mimic Pilomatrixoma resulting in diagnostic dilemma.

Malignant pilomatrixoma case report: what kind of treatment is the most suitable?

&lt;p class="abstract"&gt;Malignant pilomatrixoma is a rare malignancy with just 136 cases reported in the English literature. The tumour is described as locally aggressive, with possibility of reoccurrence and distal metastasis. Histology remains the gold standard in diagnostic. Wide surgical excision is preferred to simple excision. In the present study a case of first malignant pilomatrixoma in our hospital is described. We made an excision of the tumour and the tissue was sent on histopathology. The skin defect was covered with a local ulnar flap. Through our case report and literature review we focus on the most suitable treatment option. The tumour was not excised with appropriate safety surgical margin based on the histopathology report. Patient refused another excision and any additional treatments. The most optimal treatment has not yet been established. Most of the article’s state that primary wide surgical excision should be done, with surgical margins still being debateable. The best results were given when using Mohs micrographic surgery.&lt;/p&gt;

Solitary, subcutaneous, fixed, firm, and fast-growing nodule

Solitary, subcutaneous, fixed, firm, and fast-growing nodule

Ultra-High-Frequency Ultrasound in the Evaluation of Paediatric Pilomatricoma Based on the Histopathologic Classification.

Background: Pilomatricoma (PM) is one of the most common benign tumours in children. However, the inaccuracy of preoperative diagnosis and evaluation is high. Non-invasive examinations, including dermoscopy and ultrasound are helpful for diagnosing and evaluating PM. To date, ultra-high-frequency ultrasonographic features of PM have been rarely studied.Objective: We aimed to investigate the ultra-high frequency ultrasonographic features of PM in a large paediatric cohort and to determine the associations of these features with the clinical features of different histological subtypes of PM.Methods: This was a retrospective study. Patients who had both preoperative ultra-high-frequency ultrasonographic evaluation and pathological diagnosis of PM were enrolled. A series of infantile haemangiomas and cutaneous cysts during the same period were included as controls. Histological findings, including the stage, calcifying type, and ultrasonographic features of each lesion, were described.Results: A total of 133 patients with PM were included, and 147 PM lesions were analysed. The male-to-female ratio was 1:1.58, and the median age of onset was 91 (range: 10–188) months. On ultra-high-frequency ultrasonography, PM presented as heterogeneous (144/147, 98.0%), well-demarcated (143/147, 97.3%), and hypoechoic (126/147, 85.7%) tumours located between the deep dermis and subcutaneous tissue (139/147, 94.6%). The most common features were internal echogenic foci (135/147, 91.8%), hypoechoic rim (133/147, 90.5%), and posterior acoustic shadowing (94/147, 63.9%). Fourteen (9.5%) lesions were histologically categorized in the early stage, 58 (39.5%) in the fully developed stage, 65 (44.2%) in the early regressive stage and 10 (6.8%) in the late regressive stage. Three calcifying types, including scattered dots, clumps and arcs, were observed on histologic examination, which corresponded well with grey-scale imaging on ultra-high-frequency ultrasonography. Each calcifying type was significantly different in various histological stages (P = 0.001), among which scattered dots were mainly present in the early and fully developed stage and arc-shaped calcifying were present in the regressive stages. Calcification was observed in skin cysts, while there was more frequent posterior enhancement, less frequent posterior shadowing, and hypoechoic rim than PM. Haemangioma also presented as a hypoechoic tumour on grey-scale imaging. However, haemangioma was homogeneous and rarely calcifying.Conclusions: PM is a heterogeneous, well-demarcated, hypoechoic tumour located between the deep dermis and the subcutis on ultra-high-frequency ultrasonography. The most common features are internal echogenic foci (calcifying) and hypoechoic rim. Calcifying types can help in the staging of PM. Ultra-high-frequency ultrasound is a useful tool for the diagnosis and evaluation of PM.

Liver Metastasis of Malignant Pilomatrixoma: Devastating Outcome from A Possibly Under-Treated Case

Malignant of pilomatrixoma, known as pilomatrix carcinoma, is a rare cutaneous adnexal tumor that derives from hair matrix cells.The tumor usually occurs in male, with the predominant age range between 40 to 60 years old, located in the head and neck area. The tumor consisted of atypical basaloid cells aggregation, ghost cells, and keratinous material. We report a case of 54 years old male patient referred to Cipto Mangunkusumo Hospital Jakarta with a mass in his right upper quadrant abdomen and a lump in the axilla. The magnitude resonance imaging (MRI) and positron emission tomography (PET)-scan revealed metastatic lesions in several lymph nodes and internal organs. The patient underwent liver biopsy which showed that tumor was composed of atypical basaloid cells, amyloid-like material, keratin mass, and was diagnosed as pilomatrix carcinoma. This case is being reported due to its rarity, potential pitfalls due to histologic similarity with several other entities, and to show the importance of histopathology examination in patient’s treatment to prevent a devastating outcome.

Malherbe’s Masquerade

Introduction: Pilomatricoma, also known as calcifying epithelioma of Malherbe, was first described by Malherbe and Chenantais in 1880. It was described as a benign cutaneous tumour arising from the sebaceous glands. In 1961, its classical histopathological characteristics of epithelial cells and shadow cells were documented and hence, it was renamed as Pilomatricoma to be correct etymologically. Case Report: A 47 year old male was referred to the cytology lab from the general surgery outpatient department for a fine needle aspiration with a history of a swelling on the right side of the neck since 1 year which was gradually progressive in size, no pain/discharge. A clinical diagnosis of? sebaceous cyst was provided.On examination, solitary swelling on the right side of the neck, 5 cm below the angle of the mandible, measuring 1.5x1 cm, firm in consistency, well defined with a smooth surface and mild erythema. Skin over the swelling – pinchable. Fine needle aspiration was performed and on microscopy, the smears obtained were highly cellular and showed tight clusters of basaloid cells and few were singly dispersed. This was admixed with keratin flakes and few shadow cells, background also showed occasional multinucleate giant cells. A diagnosis of Benign adnexal tumour morphology favouring pilomatricoma was given. Following the Fine needle Aspiration cytology report, he underwent an excision biopsy. Grossly - skin covered nodular tissue bit, cut surface - grey white areas with specs of calcification. Microscopically, an encapsulated lesion composed of basaloid cells undergoing abrupt transition to the formation of shadow cells with central clearing, mixed inflammatory infiltrate and foreign body giant cells.A diagnosis of Pilomatricoma was made. Conclusion: Pilomatricoma (PMC) is a relatively uncommon benign skin neoplasm arising from the skin adnexa. Although there has been a gradual increase in the understanding of its clinical presentation and morphological featu

Clinical and pathological features of 16 cases of childhood bullous pilomatricoma

Objective To analyze the clinical and pathological features of childhood bullous pilomatricoma. Methods The clinical and pathological features were analyzed in 16 patients with bullous pilomatricoma, who visited Department of Dermatology of Beijing Children′s Hospital from 2013 to 2017. Results Among the 16 patients, 5 were males, and 11 were females. Their age of onset ranged from 4 months to 11 years, and the median age of onset was 8.5 years. Their course of disease ranged from 2 months to 4 years, and the average course of disease was 10 months. The tumors were found predominantly on the upper limbs (10 cases, including 7 on the upper arm, 2 on the shoulder and 1 on the forearm) , followed by the face (4 cases) and the neck (2 cases) . These tumors manifested as limited pushable red lumps with blister-like appearance, and telangiectasia was observed on the surface of some lesions. The diameters of the lumps ranged from 0.5 cm to 3 cm, and hard nodules could be detected in the blisters by palpation. Under dermoscopy, uniform red background was observed in 16 cases, unstructured white area in 13, unstructured blue-grey area in 4, and liner or irregular branched vessels. Two or more dermoscopic features were observed in 15 patients. All the skin lesions were resected by surgery, and no recurrence was observed during the follow-up of 1 - 5 years. Histopathological examination showed that the tumors were located in the middle to deep dermis, and mainly consisted of basaloid cells and shadow cells, as well as transitional cells between the above two kinds of cells. Varying degrees of infiltration of inflammatory cells and hyperplasia and calcification of the fibrous connective tissue were observed in the tumor interstitium, with multinucleated giant cells in some areas. There were varying degrees of infiltration of inflammatory cells, lymphangiectasis, reduction or absence of elastic fibers in the dermis between the epidermis and tumors. Conclusions Childhood bullous pilomatricoma mostly occurs on the upper limbs, face and neck. Histopathologically, the tumor consists of basaloid cells and shadow cells with lymphangiectasis and reduction of elastic fibers in the dermis. The main dermoscopic features are red background and unstructured white areas. Its prognosis is good after surgical excision. Key words: Pilomatrixoma; Child; Dermoscopy; Skin manifestations; Pathologic processes; Bullous pilomatricoma

Pilomatrixoma Masquerading as Giant Chalazion

Pilomatrixoma Masquerading as Giant Chalazion

Aggressive metastatic malignant pilomatrixoma followed by 18F-FDG PET/CT

Aggressive metastatic malignant pilomatrixoma followed by 18F-FDG PET/CT

CDX2 and LEF-1 expression in pilomatrical tumors and their utility in the diagnosis of pilomatrical carcinoma.

The Wnt signaling pathway has been implicated in the pathogenesis of pilomatrical tumors. Lymphoid enhancer-binding factor 1 (LEF-1) is a downstream component of this pathway, and Caudal-related homeobox transcription factor 2 (CDX2) has been postulated to regulate it, but little is known about expression of these transcription factors in pilomatrical tumors. Immunohistochemistry for CDX2, β-catenin, LEF-1, CK19, CK5, Special AT-rich sequence- binding protein 2 (SATB2), cadherin 17 and androgen receptor was performed on pilomatricomas (PMs) (N = 12), pilomatrical carcinomas (PMCAs) (N = 12) and non-pilomatrical cutaneous tumors (N = 18). PMs and PMCAs were positive for CDX2 (9/12 PMs, sensitivity = 75%, specificity = 100%; 11/12 PMCAs, sensitivity = 92%, specificity = 100%; P < 0.01), β-catenin (12/12 PMs, sensitivity = 100%, specificity = 94%; 10/12 PMCAs, sensitivity = 83%, specificity = 94%; P < 0.01) and LEF-1 (12/12 PMs, sensitivity = 100%, specificity = 56%; 12/12 PMCAs, sensitivity = 100%, specificity = 56%; P < 0.01). CDX2 expression was commonly focal, within a discrete subpopulation of squamoid cells. The LEF-1 expression pattern was different and discernable between pilomatrical tumors (strong, diffuse) and non-pilomatrical tumors (weak, patchy). This study reaffirms the importance of the Wnt signaling pathway in the tumorigenesis of pilomatrical tumors, and this introduces CDX2 as a possible regulator and marker of pilomatrical tumorigenesis. LEF-1 and CDX2 performed at least as well as β-catenin, if not better when taking into account expression pattern, as a diagnostic marker for PMCA, and should be considered in the workup of ambiguous primitive-appearing cutaneous tumors.

Giant pilomatrixoma: A rare case with diagnostic difficulties

Pilomatrixomas are benign subcutaneous masses that originate from the hair follicle. Dimensions do not exceed three cm. When the dimensions exceed five cm, it is called giant pilomatrixoma and is very rare. Giant PMs (pilomatrixomas) can be confused with malignancy due to their locally aggressive features and nonspecific citopathologic and radiologic findings. By presenting a 62 years old men who has a giant PM phenomenon settled in the upper extremity, we wanted to observe the difficulties encountered in the diagnosis in the light of the literature.

Pilomatrixoma: Cytodiagnosis without a “Shadow” of doubt!

Pilomatrixoma: Cytodiagnosis without a “Shadow” of doubt!

GREM1 is expressed in the cancer-associated myofibroblasts of basal cell carcinomas.

Cancer-associated fibroblasts (CAFs) play important roles in cancer progression through their complex interactions with cancer cells. The secreted bone morphogenetic protein antagonist, gremlin1 (GREM1) is expressed by the CAFs of basal cell carcinomas (BCCs), and promotes the growth of cancer cells. In this study, we investigated the expression of GREM1 mRNAs in various benign and malignant skin tumors, including various BCC subtypes. Analysis by RNA in situ hybridization (ISH) revealed that fibroblasts in the scar tissue expressed GREM1 and α-smooth muscle actin (α-SMA), whereas resident fibroblasts in the dermis of the normal skin did not express GREM1. Real-time polymerase chain reaction analysis showed significantly higher GREM1 expression in skin cancers and pilomatricomas (PMCs) than in other benign skin tumors. Tissue microarrays analyzed by RNA ISH for GREM1 expression also demonstrated that 23% of BCCs, 42% of squamous cell carcinomas, 20% of melanomas, and 90% of PMCs were positive for GREM1 expression, whereas trichoepitheliomas, eccrine poromas, hidradenomas, and spiradenomas were negative for GREM1 expression. Most BCCs that were GREM1 expression positive were of desmoplastic or mixed subtypes, and GREM1 expression was localized to activated myofibroblasts at the tumoral-stromal interface. Interestingly, most PMCs harbored GREM1-expressing fibroblasts, probably because of the inflammatory responses caused by foreign body reactions to keratin. Additionally, in BCCs, stromal GREM1 expression had a strong correlation with CD10 expression. In conclusion, GREM1 is frequently expressed by myofibroblasts in scars or in the stroma of basal cell carcinomas, suggesting that GREM1 expression can be a marker for activated myofibroblasts in the cancer stroma or in scar tissue.

Concomitant cetuximab and radiation therapy: A possible promising strategy for locally advanced inoperable non-melanoma skin carcinomas.

Non-melanoma skin cancers (NMSCs) include a heterogeneous group of malignancies arising from the epidermis, comprising squamous cell carcinoma (SCC), basal cell carcinoma (BCC), Merkel cell carcinoma and more rare entities, including malignant pilomatrixoma and sebaceous gland tumours. The treatment of early disease depends primarily on surgery. In addition, certain patients present with extensive local invasion or metastasis, which renders these tumours surgically unresectable. Improving the outcome of radiotherapy through the use of concurrent systemic therapy has been demonstrated in several locally advanced cancer-treatment paradigms. Recently, agents targeting the human epidermal growth factor receptor (EGFR) have exhibited a consolidated activity in phase II clinical trials and case series reports. Cetuximab is a monoclonal antibody that binds to and completely inhibits the EGFR, which has been revealed to be up-regulated in a variety of SCCs, including NMSCs. The present review aimed to summarize the role of anti-EGFR agents in the predominant types of NMSC, including SCC and BCC, and focuses on the cetuximab-based studies, highlighting the biological rationale of this therapeutic option. In addition, the importance of the association between cetuximab and radiotherapy for locally advanced NMSC is discussed.

Immunohistochemical analysis of CD146 expression in canine skin tumours.

CD146, a cell adhesion molecule, is overexpressed in a variety of carcinomas, including melanoma, prostate cancer, epithelial ovarian cancer, and breast cancer. The level of expression is directly correlated with tumour progression and metastatic potential. The most commonly affected organ for both neoplastic and non-neoplastic tumours is the skin. The objective of this study is to investigate the immunohistochemical expression of CD146 in canine skin tumours of epidermal or follicular origin in 53 squamous cell carcinomas (SCCs), 9 squamous papillomas, 7 infundibular keratinizing acanthomas (IKA), 21 trichoepitheliomas, 13 trichoblastomas, and 3 pilomatricomas. Immunohistochemical results showed that SCCs (90.6%), squamous papilloma (33.3%), IKA (85.7%), trichoepithelioma (85.9%), trichoblastoma (30.8%) and pilomatricoma (100%), respectively, were positive for CD146. The significant expression of CD146 in SCCs supports its importance as a useful treatment target. CD146 could also be used in differentiation of trichoepithelioma and trichoblastoma.

Diagnostic value of CT for head and neck pilomatricoma

To evaluate the CT and pathological features of head and neck pilomatricoma. We retrospectively analyzed the CT findings of 13 patients with head and neck pilomatricoma which were pathologically confirmed. Of them 7 patients received plain CT, 2 patients received contrast-enhancement, and 4 patients received plain CT plus contrast-enhancement. All the patients presented with solitary tumors, 9 of them occurred in the parotid gland region, one in the left occipital, one in the right forehead, one in the right parietal, and another one in the left eyelid. The maximal diameter of the tumors ranged from 0.6 to 2.3 cm with a mean of 1.5 cm. All lesions were well-circumscribed, with partial attachment to the overlying skin. Most of lesions were isodense relative to adjacent skeletal muscle on non-enhanced CT scans, sand-like or nodular calcifications within the masses were showed in 8 cases, and no cystic degeneration was found. On contrast-enhanced imaging, mild to moderate homogenous enhancement was showed in 3 cases, heterogeneous moderate enhancement with patchy nonenhancing necrosis area in one case, marked enhancement in one case, and complete calcification with no enhancement in one case. Head and neck pilomatricoma presents with certain characteristics on CT, which are useful in the clinical diagnosis and differential diagnosis.

Giant gluteal pilomatrixoma: An uncommon tumor in a rare localization

Pilomatriksoma sac folikulu matriksinden kaynaklanan nadir, benign bir cilt alti tumorudur. Bu tumor yetiskinlere oranla cocuklarda daha sik gorulur ve cogu bas, boyun veya ust ekstremitelerden koken alir. Gluteal bolge, pilomatriksomanin cok nadir gorulen bir bolgesidir. Multipl prezentasyon sik olmayan bir durumdur ve genellikle miyotonik distrofi, Gardner sendromu ve Turner sendromu gibi bazi ailesel sendromlar ile iliskilidir. Pilomatriksoma cogunlukla agrisiz, sert, yavas buyuyen bir cilt alti kitlesi olarak ortaya cikar ve genellikle bag dokusu ile kapsullu ve normal cevre dokudan keskin olarak sinirlanmistir. Hem klinik ve hem de radyolojik bulgular spesifik degildir ve bu nedenle histopatoloji dogru taniya ulasmak icin gereklidir. Bu lezyonlar cok dusuk malign transformasyon riskine sahiptir ve tedavisi yeterli sinirlar ile cerrahi eksizyondur. Bu yazida, genc bir kadin hastada, ust ekstremite multipl prezentasyon ile birlikte olan nadir bir gluteal pilomatriksoma olgusu sunuldu.