BACKGROUND: Pilomatrix carcinoma (PC) is a rare skin malignancy of the hair follicles matrix that tends to be locally aggressive with 10-16 % risk of metastasis mostly to the pulmonary and lymphatic system. There are no clear protocols for the management of PCs, however surgical intervention with clear margins has been highly considered in PC management to decrease risk of recurrence.
METHODS: A 40 year-old male patient presented to our clinic to evaluate an asymptomatic, slow-growing nodule localized on his left thigh. A CT scan revealed a well-defined, enhanced lesion with microcalcification. \"En bloc\" surgical resection of the lesion was performed and histopathology confirmed the diagnosis of pilomatrix carcinoma.
UNASSIGNED: Given its rarity, there are no definitive guidelines regarding PC treatment. However, surgical intervention with clear margins including wide local excision or Mohs micrographic surgery has been highly considered. In our case, wide excision of the lesion with clear margins was performed with no evidence of recurrence one year later.
CONCLUSIONS: Given the local aggressive nature of PC, appropriate surgical intervention is essential in decreasing the risk of recurrence. Wide excision with clear margins has been proposed to decrease the risk of recurrence. Additionally, total-body skin examination should be done 2-3 times annually to evaluate for recurrence or metastasis.

Malignant pilomatricoma is a rare cutaneous malignancy that is commonly found on the head and neck. We present a patient with malignant pilomatricoma of the lower extremity with intralesional calcification and giant cells, confirmed by histopathology. This patient\'s case represents a clinically important variation of malignant pilomatricoma in an uncommon anatomical location.

Pilomatrix carcinoma is a rare malignancy stemming from aberrant proliferation of matrical cells found in developing hair. This neoplasm demonstrates a bimodal age distribution and a proclivity for developing on the head or neck. Clinically, a firm, painless, violaceous nodule with overlying ulceration is commonly described. Pilomatrix carcinoma is considered a variable-grade malignancy that tends to be locally aggressive, though metastatic disease occurs in 10 to 16 percent of cases. Mortality rates range from 7 to 9 percent. Although there is no definitive treatment protocol, surgical intervention in the form of local excision or via Mohs micrographic surgery can be considered, with radiotherapy adopted as an effective alternative for nonsurgical, recurrent, or metastatic disease. Here, we describe the case of a 62-year-old man who presented for evaluation of a red, enlarging lesion on his forehead which became tender and started to bleed shortly before the patient presented to our clinic. The patient was ultimately referred to a tertiary care center for surgical excision and, at the time of this pubilcation, has been tumor-free for more than one year. This case of a rare and often unconsidered neoplasm underscores the importance of clinical suspicion and close patient follow up to prevent local recurrence, metastasis, and death.

Malignant pilomatricomas are uncommon cutaneous neoplasms in veterinary and human medicine. Pilomatrical carcinosarcoma is a rare subset of malignant pilomatricoma that has been described in man. This article reports a neoplasm with morphological features of pilomatrical carcinosarcoma in a dog. The nodular neoplasm occurred on the left lateral hock and was partially alopecic. Microscopically, the tumour was composed of a cystic carcinomatous component surrounding areas of abrupt keratinization and a sarcomatous component exhibiting bundles of spindle cells and irregular, scalloped areas of mineralized and non-mineralized osteoid matrix. The carcinomatous and sarcomatous areas were immunoreactive for pan-cytokeratin and vimentin, respectively, while immunoreactivity for e-cadherin was restricted to the carcinomatous component of the neoplasm. The unique morphological features of this tumour were similar to those described in human pilomatrical carcinosarcoma.

Malignant pilomatricoma (pilomatrical carcinoma) is a rare, locally occurring malignant tumor with a high rate of recurrence in the case of incomplete excision. This tumor has two characteristics. First, recurrences of pilomatrical carcinoma are common; second, distant metastasis is rare, but if it occurs, it is very fatal. It has characteristic features of high mitotic counts, cellular atypia, and local invasion. Although fine needle aspiration and excisional biopsy could help to confirm this tumor diagnosis, pathologic findings are critical. Pilomatricomas have some characteristic features in histological aspect, such as epithelial islands of basaloid cells and shadow cells or ghost cell. Also, various types of immunohistochemical staining are used to confirm the diagnosis. Despite the lack of clear surgical criteria, treatment is a wide local excision with histologically clear resection margins with or without adjuvant radiotherapy.

暂无摘要。

A ten-year-old male neutered cross breed dog presented for evaluation of a mass associated with the left scapular bone, identified as a carcinoma. The dog had a malignant pilomatricoma removed from the left lateral thigh 6 months earlier. Histopathology review of the cutaneous and scapular mass identified the same tumour type, confirming metastatic disease; additional metastases to the inguinal lymph node, liver and lungs were identified. Chemotherapy resulted in partial responses/stable disease of very short duration. Bisphosphonates were administered due to lack of a measurable response and worsening of the associated lameness. The patient ultimately developed a symptomatic vertebral metastasis and was euthanased. The dog survived 255 days since medical treatment was started and 455 days since surgical removal of the primary tumour. This case report suggests that medical treatment with the addition of analgesia may be able to palliate clinical signs and possibly extend survival in dogs with metastatic epithelial cancer.

Pilomatrix carcinoma is a very rare malignancy, with ~130 cases reported in the literature. In the past, pilomatrix carcinoma was considered to be a low-grade malignant tumor. Currently, however, its significant recurrence and metastatic potential has been well documented. Lymph node and systemic metastases are frequently observed. Wide surgical excision of the primary lesion is the principal modality of treatment, whereas adjuvant radiotherapy may be beneficial in local tumor control. Lymph node metastases may be treated surgically or with radiotherapy. Systemic disease is not responsive to chemotherapy, and is hence associated with a poor prognosis. Since the majority of nodal and systemic metastases present after the initial diagnosis and treatment, follow-up examinations of these patients may be warranted, despite the currently inadequate treatment options. In the present study, a case of pilomatrix carcinoma of the parotid region with early local recurrence only 2 months after complete excision with negative surgical margins is reported. The local recurrence was treated by excision and radiotherapy. The associated literature is also discussed.

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.
CONCLUSIONS: 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.

BACKGROUND: Pilomatricomas are tumors that emulate the differentiation of matrix cells of the hair follicle, showing cortical differentiation, with sequential expression of K35 and K31 keratins. Beta-catenin gene is frequently mutated in pilomatricoma, leading to beta-catenin nuclear accumulation, and to downstream expression of LEF1. Skin matrical tumors other than pilomatricoma are very rare, and comprise purely matrical tumors and focally matrical tumors. We aimed at studying cortical differentiation, beta-catenin pathway and expression of the follicular stem-cell marker PHLDA1 in a series of matrical tumors other than pilomatricoma.
METHODS: In 36 prospectively collected tumors, K31, K35, CK17, LEF1, HOXC13, beta-catenin and PHLDA1 expressions were evaluated. Five pilomatricomas were used as controls.
RESULTS: In 18 purely matrical tumors (11 matrical carcinomas, 4 melanocytic matricomas, 3 matricomas) and 18 focally matrical tumors (11 basal cell carcinomas, 3 trichoepithelioma/trichoblastomas, 4 others), sequential K35, HOXC13 and K31 expressions were found, indicating cortical differentiation. Germinative matrix cells were always CK17-, and showed nuclear beta-catenin accumulation, with LEF1 and PHLDA1 expressions.
CONCLUSIONS: Nuclear beta-catenin and LEF1 expression was highly conserved in matrical tumors, and suggested a common tumorigenesis driven by Wnt pathway activation. PHLDA1 was consistently expressed in matrical tumors and in areas of matrical differentiation.