Concurrent pilomatrix carcinoma and giant pilomatrixoma

[Pilomatricoma: a study of 22 cases]

Pilomatricoma is a common and benign skin tumor of childhood arising from the hair follicle matrix. It is an often misunderstood adnexal tumor, confused with other skin lesions. The most common sites of pilomatricome are the head and the neck. The aim of this study was to report a series of 22 cases with unusual forms collected in the dermatology department from January 2006 to May 2015. The study included 16 women and 6 men. The average age was 23.3 years (4- 80 years). Cervicofacial location was observed in 12 cases, 2 patients had multiple locations, a 4 year-old boy had frontotemporal location, a 14 year-old girl had face and forearm location and a 48 year-old patient had subungual location. Clinical features were typical in all cases, with subcutaneous nodules with a stony-hard consistency. All patients underwent excision of nodules under local anesthesia. Histological study supported a completely excised Malherbe's mummified tumor without malignancy. No patients relapsed. The originality of our study lies in the presence of exceptional locations in laterovertebral region, on limbs and in the subungual region and of unusual age of onset (80 year-old) as well as the presence of multiple tumor locations reported in 2 children.

YAP immunoreactivity is directly related to pilomatrixoma size and proliferation rate

Organ size regulation is a highly coordinated process involving complex mechanisms. Yes-associated protein (YAP) and transcriptional co-activator with PDZ-binding motif, also known as WWTR1 (TAZ) have recently been linked to organ size determination and cell proliferation. Pilomatrixoma (PM) is a benign tumor of the adnexal appendages with a certain degree of differentiation toward the matrix of the hair follicle. PM presents as a dermal nodule that usually ranges from 0.5 to 2 cm, rarely exceeding 3 cm. We recently observed a case of unusual "giant" (6.5 cm) PM. Our hypothesis was that YAP and TAZ could be related to PM growth. We analyzed YAP and TAZ immunohistochemical expression in the giant and in ten usual size PMs in relation with tumor size and proliferation rate. YAP nuclear expression was remarkably higher in the giant PM in comparison with usual size PMs and statistically correlated, in a direct manner, with size and proliferation rate of PMs. Contrariwise, TAZ nuclear expression seemed stochastic. Our findings suggest that YAP could play a role in PM growth.

Pilomatrix Carcinoma of the scalp. A case report and review of the literature

INTRODUCTION

Pilomatrix Carcinoma (PC) is a rare and malignant dermo-hypodermic tumor. Only 11 cases were reported in patients younger than 18 years old and only 13 cases were reported on the scalp.

CASE REPORT

We report the case of a 15-year-old woman who underwent cyst excision on the vertex. Anatomopathology shed light trichilemmal cyst. Five months later, she presented a first local recurrence. The tumor was removed with wide margin. Anatomopathology shed light PC. No adjuvant therapy was performed. The patient presented a second recurrence 3 months later with a parietal bone and superior sagittal sinus invasion and a lung metastasis. She underwent a craniotomy and radiochemotherapy. A third local recurrence was detected 4 months later. Three more lines of chemotherapy were performed without success.

DISCUSSION

PC is a locally aggressive tumour, with a high rate of local recurrences and metastases. PC arises de novo or through malignant transformation of a pilomatrixoma. PC were observed frequently in the white male over 50 years old. The histological diagnosis is difficult to prove. Treatment consists of a wide surgical excision. Peritumoral margins are not codified. Because of most cases are on the face and neck, Mohs Micrographic Surgery seems to be a good modality to limit margins. Radiation therapy is an adjuvant treatment. Chemotherapy can be used in metastasis case.

CONCLUSION

PC is a rare malignant tumor with high rate of disease relapse. Histological diagnosis is difficult and treatment is not standardized. Surgical procedure with wide margins is recommended to avoid the large recurrence when the staging shows no metastasis.

Pilomatrix carcinoma: 13 new cases and review of the literature with emphasis on predictors of metastasis

BACKGROUND

Pilomatrix carcinoma is a rare cutaneous tumor derived from follicular matrix cells with few cases documented in the literature.

OBJECTIVE

We sought to better characterize this tumor by analyzing its epidemiologic, clinical, and histopathologic features in 13 new cases and by reviewing the literature.

METHODS

All cases of pilomatrix carcinoma from a large regional dermatopathology practice were identified and analyzed by chart review for clinical and histopathologic characteristics. Similar characteristics were compiled from an additional 123 cases in the English-language literature. Cox proportional hazards regression models were used to determine risk factors associated with the development of metastasis for all identified metastatic tumors.

RESULTS

Our 13 tumors were most common in middle-aged to older white men and presented mostly on the head/neck. Histopathologically, tumors were asymmetric, were poorly circumscribed, were composed of basaloid and "ghost" cells, had frequent atypical mitoses, and had infrequent lymphovascular invasion. Wide excision was considered the most definitive treatment modality, but local recurrence was common. When analyzing all reported cases of metastasis using statistics, metastasis was significantly associated (hazard ratio 3.45, P < .0413) with local tumor recurrence.

LIMITATIONS

The retrospective, single-center design and the reliance on electronic medical records are limitations.

CONCLUSIONS

This study helps better characterize pilomatrix carcinoma and identifies potential predictors of metastasis.

Pilomatrix carcinoma: a case report and review of the literature

Pilomatrixoma is a common benign neoplasm of children and young adults with a female predilection. In contrast, its malignant counterpart, pilomatrix carcinoma is a rare neoplasm of older adults with a male preponderance. Pilomatrix carcinomas are locally aggressive with a tendency to recur. We report a case of a 44-year-old male who presented with an enlarging soft tissue tumor on the right upper back. Histology revealed an asymmetric, poorly circumscribed, lobulated neoplasm located deeply in the dermis with infiltration into the underlying subcutaneous tissue. The tumor was comprised of basaloid cells containing vesicular nuclei, prominent nucleoli, scant cytoplasm, and brisk mitotic activity. A focus of basaloid cells transitioning to shadow cells with central keratinized material and tumor necrosis was also present. The diagnosis of a pilomatrix carcinoma was rendered. Considering the infiltrative nature of this neoplasm with perineural and intramuscular invasion, the patient underwent 3 surgical excisions before it was completely removed.

Pilomatrix Carcinoma in the Chest Wall Around an Eloesser Open Window - A case report -

Pilomatrix carcinoma originates in the matrix cell and is marked by exophytic growing and common local recurrence. There is no established treatment for wide local invasion and metastasis of the pilomatrix besides wide surgical resection. We report a case of rapidly progressive pilomatrix carcinoma, which arose around an Eloesser open window with direct invasion to the adjacent tissue.

Giant Pilomatricoma

A 52-year-old man was examined for an ulcerated, rapidly growing reddish nodule. It was 5.5 cm high with an 11 x 6-cm base and located on the left clavicle. The lesion had been present for approximately 7 years, and the patient complained occasional burning and pain. Clinical differential diagnoses included cutaneous lymphoma, sarcoma, squamous cell carcinoma, and cutaneous metastasis. Histopathologic examination revealed a well-circumscribed tumor involving the whole dermis and the subcutis and composed of partially confluent aggregates of matrical cells admixed with eosinophilic cornified material containing shadow cells. In addition, multinucleated giant cells, areas of calcification and metaplastic ossification, edema, and hemorrhage were also observed. On the basis of histopathologic features, the diagnosis of pilomatricoma was made. Our report highlights an unusual clinical appearance of pilomatricoma that made us consider a variety of primary or secondary cutaneous neoplasms in its differential diagnosis.

A case of perforating pilomatricoma

Pilomatricoma is a rare skin neoplasm, most commonly seen in the head and neck region, and occurring in the first two decades of life. It is usually solitary and varies from 0.5 to 2 cm in diameter. Its etiology is unknown. Perforating pilomatricoma is a rare clinical variant that presents as a draining, crusted nodule or ulcer, and is reported to arise faster than the classic pilomatricoma. Herein, we report a case of 35-year-old female, who had a 4-month history of a growing mass on her leg. On physical examination, a 4-cm diameter, asymptomatic, erythematous, ulcerated mass was noted on the left anterio-lateral upper leg. The first histopathological analysis of a punch biopsy from the lesion was reported as basal cell carcinoma. Therefore, the lesion was totally excised. There were shadow cells, squamoid cells, and basaloid aggregations more prominently in the one area in the tumor. In addition, calcification, foreign body giant cells and inflammatory cells were present. Punch or excisional biopsies are preferred as a method of diagnosis for the majority of cutaneous neoplasms. If total excision is not the method of choice, multiple punch biopsies should be made from different areas in large skin tumors for correct diagnosis.

Pilomatrix carcinomas contain mutations in CTNNB1, the gene encoding beta-catenin

Mutations in beta-catenin are present in benign pilomatrixomas. beta-catenin is a downstream effector in the WNT-signalling pathway, acting as a signal for differentiation and proliferation. Mutations in CTNNB1, the gene encoding beta-catenin, are present in a wide variety of benign and malignant neoplasms. We examined beta-catenin in a series of pilomatrix carcinomas (15 cases) by using immunohistochemistry and DNA sequencing of exon 3 from CTNNB1, and compared these to a series of benign pilomatrixomas (13 cases). All 11 pilomatrix carcinomas available for examination showed nuclear localization of beta-catenin and mutations in exon 3 similar to those demonstrated in benign pilomatrixomas. Two of 11 pilomatrix carcinomas showed significant nuclear accumulation of p53, whereas this was absent in all 13 benign pilomatrixomas. Expression of nuclear cyclin D1 was similar in both benign pilomatrixomas and pilomatrix carcinomas. Clinical follow-up from the 15 malignant cases reported in this study and by others indicates that wide excision offers superior control of local recurrence, compared to simple excision. Immunohistochemical and molecular analysis of beta-catenin reveals that both pilomatrix carcinomas and benign pilomatrixomas harbour mutations in beta-catenin. This implies a common initial pathogenesis and is compatible with the proposition that pilomatrix carcinomas may at least on occasion arise from their benign counterparts.