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.

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.

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.

Pilomatrix Carcinoma-Rare Presentation of an Unusual Cutaneous Malignancy.

INTRODUCTION OR BACKGROUND: Pilomatrix carcinoma is a rare malignant neoplasm arising from the root of hair follicles, with only 150 cases described in the world literature. It is most commonly seen in the head and neck region. CASE PRESENTATION: We describe a case of malignant pilomatrix carcinoma in a 62-year-old gentleman presenting as a solitary globular mass over the right anterior chest wall along with a brief review of literature. DISCUSSION AND CONCLUSION: Surgical excision with a wide margin is the current standard of care for chest wall pilomatrix carcinoma and is associated with the least recurrence. Role of radiation as definitive treatment of the primary or as adjuvant therapy has not been clearly established.

Periocular pilomatrixoma in childhood: Clinical feature and differential diagnosis.

PURPOSE: To explore the clinical characteristics, imaging features, and differential diagnosis of periocular pilomatrixoma in children and provide evidence for clinical diagnosis and treatment. METHODS: Retrospective analysis of the clinical characteristics, preliminary diagnosis, imaging features, treatment, and follow-up of the cases of pediatric periocular pilomatrixoma treated at our hospital. RESULTS: A total of 59 patients from 4 months to 13 years of age (median age 4 years) were collected; 18 cases (30.51%) were misdiagnosed as other diseases in preliminary diagnoses. Seven cases underwent computed tomography (CT) examination, with CT value ranging from 63.4 Hounsfield Units (HU) to 952.0 HU (median value 151.0 HU). Six cases underwent magnetic resonance imaging (MRI) examination; two patients underwent an enhanced scan. The results showed that the rim of the lesion was enhanced, but the contents were not enhanced. All patients underwent surgical treatment. No recurrence was found from 1 month to 5 years of follow-up. CONCLUSIONS: Periocular pilomatrixoma is a relatively common tumor in children, which can easily be misdiagnosed clinically as other diseases, such as sebaceous and dermoid cysts. Although not generally recommended, CT can be of significant value in the diagnosis of pilomatrixoma. MRI is of little value in the diagnosis of this disease. If CT images show high or density, the possibility of pilomatrixoma should be considered.

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.

Surgical experiences in pediatric pilomatricoma: punch incision and elliptical excision.

BACKGROUND: As pilomatricoma is a common adnexal skin tumor often occurring in exposed areas, dermatologists focus on minimizing postsurgical scarring. METHODS: This retrospective study included patients aged < 19 years who underwent surgical treatment for pilomatricoma at a single university hospital from 2015 to 2021. Patient demographics, tumor characteristics, and surgical outcomes were analyzed according to the surgical methods including punch incision and elliptical excision. RESULTS: Overall, 75 patients and 79 lesions were included in the study. The mean age of the patients was 8.4 years, and 48 patients (64.0%) were females. The face was the most common site of pilomatricoma (51.9%), and within the face, the cheeks were the most common sites. No recurrence was observed in the elliptical excision group, while one case of recurrence (4.5%) was observed in the punch incision group. The mean length of the wound was 2.00 cm in the elliptical excision group, which was longer than that in the punch incision group (0.49 cm; p < .001). CONCLUSIONS: Considering that surgery is the gold standard treatment for pilomatricoma, punch incision may be useful as an alternative surgical option for pilomatricoma in children.

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.

Commonly Misdiagnosed Facial Lesion: Pilomatricoma.

Pilomatricoma, also known as Pilamatrixoma or Malherbe's calcifying epithelioma, is a benign skin tumour with a bimodal age distribution between the paediatric and elderly age groups. Although it was previously thought to be rare, recent studies have revealed that it is quite common. Typically, pilomatricoma is diagnosed following histopathological examination of the lesion as it is frequently misdiagnosed with other types of skin pathology. In our case, the child presented with painless swelling of the left infraauricular region. The initial cytology and imaging were unable to provide a definite diagnosis. An excision biopsy was done, and a histopathological examination was suggestive of Pilomatricoma. Therefore, Pilomatricoma ought to be considered in the differential diagnosis of head and neck lesions in hopes of providing a better understanding on this pathological lesion.

Pilomatrix Carcinoma In A 4-Year-Old Child With An Unusual Presentation.

Pilomatrix carcinoma is a rare, locally aggressive variant of pilomatrixoma with a high rate of recurrence and risk of distant metastasis. We report an unusual presentation of a pilomatrix carcinoma in a 4-year-old male child who presented with recurrent lesions on his left cheek. At the age of 1 month of life, he presented with a soft tissue swelling on his left cheek. The lesion showed a circumscribed proliferation of basaloid cells with central areas of eosinophilic ghost shadow cells and intermediate cells. Basaloid nests showed round to oval, hyperchromatic nuclei with open nuclear chromatin, prominent nucleoli and frequent mitoses but no marked nuclear pleomorphism or infiltration was identified. The lesion recurred twice at the same site. Both recurrences showed similar morphology as the primary tumour however there were extensive areas of stromal necrosis, infiltrating edges, frequent mitoses with atypical forms, and lymphovascular invasion. There was no marked nuclear pleomorphism. Morphological features favoured a diagnosis of pilomatrix carcinoma. The child is still on follow-up and no recurrence has been identified to date. Pilomatric carcinoma is rarely reported in infants. Due to its rarity, aggressive histological features may be missed.

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.

Rare case of multiple and perforating pilomatrixomas in a young girl with lymphovascular malformation reveals a potential new disease association.

This report details the case of a girl of primary school age who was referred to our plastic surgery department with an ulcerating lesion on the nape of her neck. A firm mass was palpable in the underlying subcutaneous tissue. This lesion was accompanied by two smaller firm nodules: one in the adjacent tissue and another in the left preauricular region. Ultrasound and MRI demonstrated multiple calcified nodules confined to the subcutaneous tissue. An incisional biopsy of the ulcerating lesion confirmed a diagnosis of perforating pilomatrixoma; the lesion was subsequently excised, with no sign of recurrence at 3-month follow-up. The patient had a history of lymphovascular malformation (LVM) and a paternal history of Gardner's syndrome. Pilomatrixoma and Gardner's syndrome have a well-documented association in existing literature; aberrant Wnt/beta-catenin signalling is common to both. Recent laboratory studies suggest this pathway is also implicated in the pathogenesis of LVM.

Giant pilomatrixoma with bullous appearance on the back: A case report and discussion of misdiagnosis.

Pilomatrixoma is a benign, asymptomatic skin tumor that forms from hair follicle matrix cells. Most are under 3 cm in diameter and occur on the head, face, or neck. Bullous appearance is very rare in pilomatrixoma. In this case report, we present a case of bullous pilomatrixoma of unusual size, region, symptoms, and patient age. It had been misdiagnosed as a keloid and as dermatofibrosarcoma protuberans. Early treatments were ineffective. The patient approached our outpatient facility and underwent excision. He was then diagnosed with pilomatrixoma by pathological examination. The clinical appearance of this case was quite difficult to diagnose, even MRI and B-ultrasonic examinations provided limited diagnostic evidence. Given the revelations from this case, we reemphasize the importance of performing a biopsy (if patients refused operation or preferred conservative treatment) before any invasive treatment to minimize economic or time loss of patients who have difficulties in diagnosis.

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.

Ossifying pilomatricoma and a novel hypothesis for its pathogenesis: A case report and comprehensive literature review.

RATIONALE: Pilomatricoma is a benign skin appendageal tumor derived from hair follicle matrix cells that commonly affects the head, neck, and upper extremities of the pediatric population. Since the original tumor description, diverse variants have been reported in the literature. Pilomatricoma with florid osseous metaplasia is described as an ossifying pilomatricoma and is recognized as a distinct variant of this benign tumor. However, the pathogenesis of this variant remains unclear. In this study, we present an uncommon case of ossifying pilomatricoma and address the pathogenesis of metaplastic ossification through a comprehensive literature review. PATIENT CONCERNS: A 14-year-old boy presented with an asymptomatic protuberant mass in the preauricular region. DIAGNOSIS: Based on its clinicopathological features, we diagnosed the lesion as an ossifying pilomatricoma. INTERVENTIONS AND OUTCOMES: The lesion was surgically removed under local anesthesia. The postoperative course was uneventful during the 6-month postoperative follow-up. LESSONS: We suggest that metaplastic ossification in ossifying pilomatricoma represents another feature of foreign body reaction to keratinous materials containing shadow cells in old lesions and a walling-off phenomenon to prevent exposure of surrounding tissues to keratinous materials.