A comparative study of pilomatricoma and epidermoid cyst with ultrasound.

AIM: 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. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Cranial pilomatricoma: a diagnosis to consider.

Pilomatricomas are benign tumors of the hair follicle that occur frequently in the scalp region. They occur most often in children. We describe a case of pilomatricoma in a teenager, referred to neurosurgery for excision. This diagnosis should be considered in the workup of scalp lesions, and this case report should serve to draw attention to this entity.

Giant Pilomatricoma Mistaken for a Malignant Tumor.

Pilomatricomas are tumors originating from the matrices of hair follicles. Giant pilomatricomas, defined as pilomatricomas that are 5 cm or larger, are benign but may appear malignant clinically. We present the case of a 69-year-old man with a rapidly growing mass on his scalp. When he visited our department, the tumor measured 10.0×6.0×4.0 cm and showed inflammation and ulceration. Magnetic resonance imaging and 18 F-fluorodeoxyglucose positron emission tomography-computed tomography showed findings resembling lymph node metastasis from a malignant tumor. However, upon an incisional biopsy, the tumor was diagnosed as a pilomatricoma. Therefore, we performed an excisional biopsy instead of radical surgery and lymph node dissection. The tumor was ultimately diagnosed as a giant pilomatricoma based on the excisional biopsy, and the patient received reconstruction only at the site of the defect. A giant pilomatricoma can be mistaken for a malignant tumor due to its characteristics. In such uncertain cases, it can be helpful to first perform an excisional biopsy.

Calcifying epithelioma of Malherbe - a rare localization.

Calcifying epithelioma of Malherbe, also known as pilomatricoma or pilomatrixoma, mostly arises in the matrix hair follicle. It generally affects the head and neck, upper extremities, and trunk, with the lower extremities being a rare exception. We hereby present a case of a 31-year-old male patient who presented with a small, firm, subcutaneous mass over the left malleolus, which was provisionally diagnosed as lipoma. Surgical excision was performed, and the histopathology report revealed it to be pilomatricoma of the left malleolus.

A newly growing asymptomatic facial lesion.

A 23-year-old man presenting with a 1-year history of a lesion of the right cheek. We highlight this case for awareness as this tumour may mimic other benign lesions, such as pilomatrixoma or benign cysts, as it does not have any uniquely identifying clinical or dermoscopic features. Additionally, it is of concern as malignant transformation can occur and therefore surgery should be considered as both for diagnostic and therapeutic benefit.

Pilomatrical Acanthoma: An Extremely Rare Intraepidermal Variant of Pilomatricoma.

ABSTRACT: Pilomatrical differentiation can be observed in a variety of benign and malignant tumors, with the most common prototype being pilomatricoma. Pilomatricoma often presents in the deep dermis or subcutis, and the sole involvement of epidermis is extremely rare. In our current case series, specimens from 5 patients were included with an average age of 68 years. All lesions presented as solitary verrucous or keratotic papules on the extremities, with 1 lesion having a prominent horn. All lesions have a variable mixture of basaloid matrical cells and shadow cells, and all lesions express ß-catenin (strong nuclear and cytoplasmic), lymphoid enhancer-binding factor 1 within the matrical component, and pleckstrin homology-like domain family A member 1. The histomorphology and immunoprofile of all lesions are of pilomatrical differentiation, confined to the level of the epidermis. Based on these findings and analogous to the terminology used for other benign intraepidermal proliferations (hidroacanthoma simplex and epidermolytic acanthoma), we propose the term "pilomatrical acanthoma" for these rare lesions.

Pilomatricoma with florid osseous metaplasia: A common tumor with rare histopathological finding.

Pilomatricoma, also known as calcifying epithelioma of Malherbe, is a common benign skin adnexal tumor with differentiation toward hair cortex cells, commonly seen in head and neck region of children. It is usually solitary. Herein, we present a rare case of pilomatricoma with extensive osseous metaplasia as a thigh swelling in an adult female, considered clinically to be a sebaceous cyst. Florid osseous metaplasia is extremely rare in cases of pilomatricoma. To date, fewer than 10 cases of pilomatricoma with extensive osseous metaplasia at different sites have been reported in the English literature.

Pilomatrical Tumor of Low Malignant Potential: A Tumor Between Pilomatricoma and Pilomatrical Carcinoma.

ABSTRACT: We report a case of pilomatrical tumor showing intermediate histological features between pilomatricoma and pilomatrical carcinoma. The lesion recurred twice with the same histological features. Similar cases were was probably called aggressive or proliferating pilomatixoma; we think that the term pilomatrical tumor of low malignant potential is more suitable for this lesions. Excision with wide free margins and follow-up are recommended.

Pseudocystic pilomatricoma: A new variant and review of the literature.

A classic pilomatricoma, which usually presents with an asymptomatic, solitary, firm, subcutaneous nodule in the head, neck, or extremities of the paediatric population, is easily diagnosed based on its characteristic clinical and histopathological features. However, its variants often pose particular diagnostic challenges to clinicians due to their rarity and diverse clinicopathological features. We present a new pseudocystic variant, manifesting as solid lesions floating in a fluid-filled sac.

Proliferating pilomatricoma in a 9-year-old girl.

Proliferating pilomatricoma is a rare, benign tumor of hair matrix origin that rarely occurs in children. We report the case of a 9-year-old girl with a rapidly growing, proliferating pilomatricoma located on the glabella. The lesion was embolized and surgically excised, with histopathological examination of the tissue confirming the diagnosis of proliferating pilomatricoma.

A skin tumor from an orthopedic oncology perspective: Pilomatrixoma in extremities (11 years experience with 108 cases).

Pilomatrixoma, also known as calcifying epithelioma of Malherbe, is a benign skin neoplasm originating from hair follicle matrix cells. Pilomatrixoma is a common skin neoplasm that is often misdiagnosed as another type of skin condition. The aim of our study is to review 11 years' worth of experience in examining clinical and histopathological presentations, imaging findings, management approaches, and treatment outcomes of pilomatrixoma at a tertiary hospital. A review of the pathology database revealed that 108 extremity pilomatrixomas were excised between 2007 and 2018. Hospital charts, and pathology and orthopedic clinic records, were reviewed for patient data such as age, gender, clinical and histopathological presentations, preoperative diagnosis and imaging results, management approach, recurrence, and treatment outcomes. The main presenting symptom was a hard, subcutaneous, slowly growing mass. The preoperative diagnosis was accurate and consistent with the pathological diagnosis of pilomatrixoma in only 35 cases (32%). The optimal diagnostic tool for pilomatrixoma seems to be ultrasound imaging of superficial tissue, and the optimal first-line treatment might be surgical excision with clear margins. However, pilomatrixoma is a benign tumor, with atypical forms, and there no tumor-specific diagnostic tool is available other than careful histopathological examination.

Sarcomatoid pilomatrix carcinoma.

Pilomatrix (pilomatrical) carcinoma is a rare cutaneous adnexal tumor with matrical differentiation and recurrent and metastatic potential. Sarcomatoid pilomatrix carcinoma is a rare variant which shows a sarcomatoid component intermingling with the epithelial one. There are only 4 cases previously published. We present an additional case on the hand of a 78 year-old man which appeared as a 6 mm hyperkeratotic, focally ulcerated plaque. A shave biopsy demonstrated a dermal infiltrative neoplasm, composed of markedly atypical-appearing basaloid cells with focal necrotic/ghost cells, as well as an intimately associated population of atypical oval to spindle-shaped cells. Both the epithelial and the sarcomatoid components expressed cytokeratins (CKs) AE1/AE3, CK 5/6 and CAM 5.2, as well as beta-catenin and LEF-1. The tumor failed to express CK7, CK20, S100, thyroid transcription factor 1 (TTF1), CDX2, prostate-specific antigen (PSA) and CD34. The tumor was completely excised with Mohs surgery, and there has been no recurrence in the 8 months of follow-up to date.

Giant Pilomatricoma Arising as a Rapidly Growing Vascularized Tumor in a Child.

In this observation, we report an unusual presentation of a pilomatricoma in an 8-year-old girl who was initially referred to the department of vascular medicine for diagnosis and care of a suspected mixed lymphatic venous malformation. The lesion on her left shoulder presented as a giant bluish-purple red solitary mass, painful and rapidly growing, measuring 7 cm in anteroposterior diameter. This mass did not present the typical characteristics of a lymphatic venous malformation but exhibited warning signs of malignancy on clinical examination and imaging. The diagnosis of pilomatricoma was reached by fine-needle aspiration biopsy of the mass, showing mummified "ghost" squamous cells and a granulomatous inflammatory reaction stroma with scattered multinucleated giant cells and no sign of malignancy. Complete surgical excision associated with plastic surgery was curative. Diagnostic and management approach to skin lesion in childhood is subject of great concern for health care professionals, including dermatologists and vascular medicine specialists who may be confronted with this atypical presentation of one of the most common causes of superficial neck masses in children.

Pilomatrixoma: A Comprehensive Review of the Literature.

INTRODUCTION: Pilomatrixoma, also known as calcifying epithelioma of Malherbe, is a superficial benign skin tumor that arises from hair follicle matrix cells. Although pilomatrixomas are well-recognized lesions, clinically they are frequently misdiagnosed as other skin conditions. By reviewing all the literature over the past 10 years, the aims of this article are to analyze the cause, clinical presentation, management, and outcome of pilomatrixoma among children and adults to gain a more complete understanding of this lesion in today's clinical context. METHODS: A MEDLINE and EMBASE search was conducted from January 2005 to February 2015 using a combination of the terms: "child," "childhood," "adult," and keywords: "pilomatrixoma," "pilomatricoma," and "calcifying epithelioma of Malherbe." A total of 150 articles were reviewed. RESULTS: The lesions occurred most commonly in the first and second decades (mean age 16 years and 7 months). The commonest presentation was of an asymptomatic, firm, slowly growing, mobile nodule. Only 16% were accurately diagnosed on clinical examination. Imaging in the form of ultrasound, computed tomography, and magnetic resonance imaging has been reported. Pathological diagnosis was achieved through incision, punch, and shave biopsies. Pathological findings are discussed and summarized in this review. CONCLUSION: Pilomatrixomas are thought to arise from mutation in the Wnt pathway and has been linked to several genetic conditions. It is commonly misdiagnosed preoperatively; however, with better awareness of the lesion, it can be appropriately treated while avoiding unnecessary diagnostic tests. Complete surgical excision with clear margins is almost always curative.

Giant Pilomatrix Carcinoma of the Face.

This case report describes an unusually large facial pilomatrix carcinoma (PC) in a 60-year-old man. This PC had been growing slowly for 11 months and had recently ulcerated. It measured 9 cm × 7 cm × 5 cm. Initial punch biopsy findings were inconclusive. The tumor was excised in total with 5-mm margins in a supra-superficial musculoaponeurotic system plane. The defect was reconstructed with a cervicofacial bilobed rotational advancement flap. Histopathologic findings confirmed the diagnosis of PC. There was no lymph node spread or distant metastasis. The patient recovered with a good esthetic result. This case represents one of the largest facial PCs reported in the literature. Diagnostic challenges are discussed, and the literature is reviewed.

Pilomatricoma: An unusual cause of lump in a male breast.

We present the case of a 48-year-old man who presented with a painless, progressively increasing lump in the left breast. The mammographic and sonographic appearance of the lesion was suspicious for malignancy. Fine needle aspiration cytology and histopathologic examination confirmed the diagnosis of pilomatricoma. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 46:209-211, 2018.

Punch and Scoop Technique for Removing Pilomatricoma.

Pilomatricomas are benign calcifying neoplasms derived from follicle matrix cells. Standard treatment for pilomatricomas involves complete surgical excision, with an overall low rate of recurrence. We discuss a simple alternative surgical technique that allows for removal of the lesion with less residual defect than complete excision.

Anetodermic pilomatricoma: clinical, histopathologic, and sonographic findings.

Pilomatricoma is a benign cutaneous tumor originatingfrom hair matrix cells. Anetodermic changes inthe skin overlying pilomatricomas are sometimesreported, although their precise mechanisms remainunknown. We present an unusual case of anetodermicpilomatricoma on the upper extremity of a 17-yearoldboy and report its clinical, histopathologic, andsonographic findings.