Integrating vascularity into the pattern classification of pilomatricomas on ultrasound provides a more competent approach for discriminative evaluation.

BACKGROUND: Pilomatricoma has various manifestations on color Doppler ultrasound, and a differential diagnosis is challenging. The objective of this study was to investigate which characteristics of skin lesions on color Doppler ultrasound are effective in distinguishing pilomatricoma from epidermoid cyst and dermatofibrosarcoma protuberans. MATERIALS AND METHODS: Records of patients with pilomatricomas (n = 63), epidermoid cysts (n = 76), and dermatofibrosarcoma protuberans (n = 19) who underwent color Doppler ultrasound evaluation and surgical excision were reviewed. The anatomical distribution and color Doppler ultrasound characteristics of these lesions were analyzed. The 63 pilomatricomas were categorized into five types based on their color Doppler ultrasound characteristics, and the roles of these five types in the differential diagnosis of the aforementioned diseases were studied. RESULTS: Pilomatricomas, epidermoid cysts, and dermatofibrosarcoma protuberans exhibited some similar characteristics. Dominantly markedly hyperechoic or hyperechoic appearance, posterior acoustic shadowing, and the presence of vascularity were the major characteristics of pilomatricomas. The pilomatricomas could be categorized into five types, with type II having a diagnostic performance of sensitivity of 65.08%, specificity of 98.95%, area under the receiver operating characteristic curve (AUC) of 0.743, positive predictive value of 97.62%, and negative predictive value of 81.03% for the diagnosis of the aforementioned skin diseases. CONCLUSION: A combination of dominantly markedly hyperechoic or hyperechoic appearance, posterior acoustic shadowing, and the presence of vascularity exhibits higher diagnostic performance for the differential diagnosis of pilomatricomas, epidermoid cysts, and dermatofibrosarcoma protuberans.

Dermotoscope assisted diagnosis of adolescent bullous pilomatricoma: six case reports.

BACKGROUND: Pilomatricoma (PM) is a cutaneous benign neoplasm derived from the hair matrix. It clinically presents as a solitary and firm nodule overlying normal epidermis and is usually not easy to be noticed at early stage. Nevertheless, when special bullous lesion occurs in a short time or even ulcerates, preoperative diagnosis by a dermatologist is often challenging especially when the pediatric patients refuse biopsy. CASE PRESENTATION: We present six bullous PM cases and particularly conduct correlation analysis on the dermotoscopy and histopathology detection data. The basic information, medical history, symptoms and lesion morphology results of the patients were also provided. We found that the incidence of bullous PM was higher in females than in males, and most patients were adolescents and the predilection location seem to be consistent in the vaccine injection site. The dermatoscopic features of bullous PM reported were luminous yellow structure below, with gray-blue homogeneous areas and branched capillary. The histological features were consistent with PM, and evident epidermis bullae were above the tumor with extraordinary dilation of lymphangion in the upper dermis. The patients described in this study were Chinese patients in Han population included 4 females and 2 males, coincidentally, they are almost teen-age, respectively are 5,11,17,19,21,22 year-old. CONCLUSIONS: This study reported and analyzed the dermotoscopy and clinical characteristics of bullous PM, dermotoscopy may guide as a rapid and reliable technique in bullous PM diagnosis.

Spatial transcriptomics of a giant pilomatricoma.

Pilomatricomas (PMs) are common benign adnexal tumors that show a predilection for the head and neck region and are characterized at the molecular level by activating mutations in the beta-catenin (CTNNB1) gene. Giant PMs are a rare histopathological variant, according to the World Health Organization, which are defined by a size greater than 4 cm and are reported to show upregulation of yes-associated protein compared to PMs of typical 1-3 cm size. We describe the case of a 67-year-old man with an 8 cm giant PM involving his temporal scalp, whose PM we characterized by 10X spatial gene expression analysis. This revealed five total transcriptomic clusters, including four distinct clusters within the giant PM, each with a unique transcriptional pattern of hair follicle-related factors, keratin gene expression, and beta-catenin pathway activity.

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.

Cytomorphological spectrum of pilomatricoma - A series of 28 cases.

BACKGROUND: Pilomatricoma is a benign tumour that originates in the outer sheath of the hair follicle root. The clinical diagnosis of this rare entity is often missed, possibly due to a lack of awareness. Its characteristic cytomorphological features are sheets of ghost cells, basaloid cells, calcification and foreign body giant cell reaction. However, the above features may not all be present in all cases, rendering cytological diagnosis difficult. MATERIALS AND METHODS: This retrospective study included all cases of pilomatricoma diagnosed on fine needle aspiration over a period of 4 years. The histopathological diagnosis was retrieved for the cases wherever possible. A detailed histopathological and cytological evaluation was performed for the various components-basaloid cells, ghost cells, calcified debris, foreign body giant cells, bare nuclei, neutrophils, and macrophages-and they were graded on a scale of 0 to 3+. RESULTS: The 28 cases included 8 female and 20 male patients with a mean age of 34.6 years. Most cases (22 cases; 78.6%) were located in the head and neck, with the scalp being the most common site. Twenty-five cases were cytologically diagnosed as pilomatricoma based on a variable admixture of the various components-nests of basaloid cells, ghost cells, foreign body giant cell reaction, calcified debris and viable squamous cells. However, in two cases which showed an absence of basaloid cells, a differential diagnosis of epidermal inclusion cyst was also included. Another case showed a predominance of basaloid cells with a paucity of ghost cells, so a differential diagnosis of adnexal tumour was also included. Among all the cytological parameters, sheets of ghost cells followed by nests of basaloid cells and foreign body giant cell reaction had the highest sensitivity in the cytological diagnosis of pilomatricoma. CONCLUSION: The presence of sheets of ghost cells is the most sensitive parameter for the cytological diagnosis of pilomatricoma. It is important that pilomatricoma should be considered in the differential diagnosis of subcutaneous masses, particularly in the head and neck region.

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.

Melanocytic matricoma: A report of three cases, review of the literature, and suggestion of a new terminology.

Melanocytic matricoma is a rare, biphasic adnexal tumor. It typically presents as a pigmented papule on the sun-damaged skin of elderly patients. Histopathology shows a dermal nodule composed of basaloid cells, ghost cells, and deeply pigmented dendritic melanocytes. The basaloid cells are usually positive for ß-catenin and these tumors show overlapping histopathological and molecular features with pilomatricoma. Here, we review the literature on melanocytic matricoma and present three new cases. We suggest different terminology to reflect the overlapping features with pilomatricoma that recognizes that melanocytic matricoma is likely to be a variant of pilomatricoma associated with melanocytic hyperplasia. Although melanocytic matricoma is usually considered benign, malignant transformation has been reported. This highlights the need for increased awareness of this entity.

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.

Multiple pilomatricomas in a child with xeroderma pigmentosum: Coincidence or association?

The association of multiple pilomatricomas with xeroderma pigmentosum has not been described. We report a case of a child with multiple pilomatricomas and photosensitivity who was found to have a pathogenic variant in exon 4 of XPA and a likely pathogenic variant in COL6A1.

[Benign skin neoplasms in children]. / Gutartige Hauttumoren bei Kindern.

There are many different types of skin neoplasms in children and most are benign. Dermatologists should be able to differentiate between the various types of benign skin neoplasms and be able to recommend optimal treatment to concerned patients. Surgical removal of benign skin neoplasms is often the only treatment option. The aim of this paper is to provide a general overview of epidermal lesions (e.g., inflammatory linear verrucous epidermal nevus [ILVEN], nevus sebaceous), tumors of the epidermal appendages (e.g. pilomatrixoma), cutaneous neoplasms (e.g. angiofibroma), fibromatoses (e.g., knuckle pads), tumors comprised of fat, muscle, or bone tissue (e.g., osteoma cutis, subungual exostosis), epidermal cysts and pseudocysts, and pathologic fibrosis reactions after dermal injury (keloid). Scientific data are scarce and only in the last decade has it been possible to perform histopathological examinations and genetic studies together with detailed phenotyping to gain new understanding of the pathogenetic mechanisms.

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.

Ultrasound findings in 156 children with 169 pilomatricomas.

BACKGROUND: Cutaneous lesions present a diagnostic challenge to radiologists and clinicians alike. Pilomatricoma is the second most common skin neoplasm in childhood, yet there are limited reports in the literature focusing on imaging in pediatric patients. OBJECTIVE: To characterize the typical and atypical US features of pilomatricoma in pediatric patients and to determine the performance of the adult-based Solivetti classification for assessing pilomatricomas in children. MATERIALS AND METHODS: We retrospectively reviewed 169 US scans of pathologically proven pilomatricomas in 156 children performed over a period of 66 months. We evaluated images for the size of the lesion, borders, morphology, content, calcification, location on the skin and Doppler characteristics. RESULTS: Most of the pilomatricomas presented as single dermohypodermic lesions with peripheral vascularity on color Doppler interrogation. The cheek was the most common location, followed by the arm. Solivetti type 2 US pattern was the most frequent, and peripheral hypoechoic halo was only observed in this type. One child had an anetodermic pilomatricoma, and 11 children had multiple lesions. CONCLUSION: We showed that pilomatricomas exhibit variable sonographic patterns. In our cohort, less than 50% of the lesions showed the characteristic hypoechoic rim and less than 30% of the cases presented as diffusely hyperechoic masses with posterior acoustic shadowing. Our results show that the Solvetti classification for the US assessment of pilomatricomas can be of value in children.

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.

A rare case of post-traumatic infected pilomatricoma of the finger of the hand diagnosed after performing radioiodine therapy.

We present the clinical case of a young woman with pilomatricoma of the finger, a very rare location. The patient got infected after receiving radioiodine therapy to treat a thyroid carcinoma. Given the patient's high functional requirements we choose a minimal treatment which allowed her to maintain a sufficient functionality.

Bowen disease with matrical differentiation: Report of an exceptional histopathologic presentation.

Matrical differentiation is the distinctive feature of pilomatricoma and other purely matrical adnexal neoplasms; additionally, foci of matrical differentiation have been also described in hybrid cysts of Gardner syndrome, as well as in a wide variety of benign and malignant cutaneous tumors, including basal cell carcinoma. We report an exceptional case of Bowen disease exhibiting multiple foci of matrical differentiation, as confirmed by means of immunohistochemical studies. Several types of divergent, non-squamous differentiation have been exceptionally reported in cutaneous squamous cell carcinoma in situ (cSCCIS), including sebaceous, mucinous/glandular, poroid, tricholemmal, and neuroendocrine differentiation; matrical differentiation may be added to this list. Our findings further emphasize the undifferentiated nature of neoplastic cells in cSCCIS.

Distinguishing a Trichilemmal Cyst From a Pilomatricoma With Ultrasound.

OBJECTIVES: To determine whether ultrasound (US) could distinguish a trichilemmal cyst from a pilomatricoma preoperatively. METHODS: Ultrasound images of 61 pathologically proven trichilemmal cysts and 90 pathologically proven pilomatricomas were analyzed retrospectively. Two radiologists evaluated several US features. The sensitivity, specificity, Youden index, and predictive values of statistically significant US features were assessed. Parallel combined tests, serial combined tests, or both were performed to identify US features with high statistical significance. RESULTS: Results from individual US features were not satisfactory; however, serial combined tests that included absence of complete internal echogenic foci, absence of a hypoechoic rim, absence of peritumoral hyperechogenicity, and absence of vascularity showed higher diagnostic utility. The sensitivity, specificity, Youden index, positive predictive value, and negative predictive value for correctly identifying a trichilemmal cyst were 74%, 88%, 0.62, 80%, and 83%, respectively. If 1 of these 4 US features was not a match for a trichilemmal cyst, pilomatricoma was considered. CONCLUSIONS: It may be possible to distinguish trichilemmal cysts from pilomatricomas preoperatively using US. A combined test is superior to using any individual US feature.

Cutaneous ultrasound and its utility in pediatric dermatology. Part I: Lumps, bumps, and inflammatory conditions.

High-frequency ultrasonography represents a promising tool for pediatric dermatologists. It is a non-invasive diagnostic technique that is particularly appealing when working with children. It can be easily performed at the patient's bedside, avoiding diagnostic delays, sedation, or multiple visits. It represents a useful adjunct to clinical examination and can enhance our understanding of cutaneous diseases. Patient cooperation and limited training and experience are the main challenges for cutaneous ultrasonography in pediatric dermatology. This review describes cutaneous ultrasonography and the nuances of its use in the pediatric setting, followed by the ultrasonographic findings of cutaneous lumps, bumps, and inflammatory dermatoses commonly encountered in pediatric patients.

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.

Syndromes associated with multiple pilomatricomas: When should clinicians be concerned?

BACKGROUND: Multiple pilomatricomas have been linked to various syndromes. However, these associations are poorly defined, leaving practitioners conflicted on management of these patients. OBJECTIVE: To perform a comprehensive review to clarify the strength of these relationships and identify which patients may benefit from additional screening and/or genetic screening. METHODS: A literature search was performed using the PubMed, Ovid, and Cochrane databases. Syndromic, familial, and sporadic cases of multiple pilomatricomas were stratified based on number of pilomatricomas. This information was graphed for visual comparison. RESULTS: Sixty-six syndromic cases from 52 publications were identified, with the majority (54) of cases representing myotonic dystrophy, familial adenomatous polyposis-related syndromes (including Gardner syndrome), Turner syndrome, or Rubinstein-Taybi syndrome. Twenty-five of the 54 cases (46.3%) had six or more pilomatricomas. Of sporadic cases, 128 out of 134 (95.5%) had five or less pilomatricomas. LIMITATIONS: Most articles were case reports and series, which are vulnerable to publication bias. Specific details were not explicitly noted in some original articles, and incomplete data could not always be included in analysis. Syndromes may have been missed in sporadic cases. CONCLUSION: The presence of six or more pilomatricomas is highly suggestive of an underlying syndrome (>95% specificity). These patients should undergo additional screening. Patients with less than six pilomatricomas and family history of myotonic dystrophy, first-degree relative with colon cancer or FAP-related syndrome, or family history of pilomatricomas should also undergo further screening.

Pilomatrical carcinosarcoma of the temple: A case report.

Pilomatrical carcinosarcoma is a very rare entity, with only six cases reported until now. This report describes the case of a 100-year-old woman with a mass on the left temple that had existed for several decades but had recently grown in size. Histology showed an asymmetric lesion composed of basaloid cells, spindle cells, and "shadow" or "ghost" cells. Cells had atypical hyperchromatic nuclei with prominent nucleoli, high mitotic activity, and atypical mitosis. In the central area, an epidermal cyst-like structure was seen. The diagnosis of pilomatrical carcinosarcoma was rendered. This case appeared to have arisen from malignant transformation of a pilomatricoma because of the long clinical history and existence of a benign epidermal cyst-like structure. In addition, the observation that the basaloid cells and spindle cells showed a gradual transition from one to the other and that both types were positive for ß-catenin would seem to support a common clonal origin for the carcinomatous and sarcomatous components.