Atypical fibroxanthoma-a diagnosis of exclusion!

Fibrohistiocytic tumors of the skin comprise a large range of lesions. One such tumor is the atypical fibroxanthoma (AFX), which is widely considered as a "pseudomalignant" tumor. It is derived from fibroblasts and expresses a variety of histiocytic markers. We present a case of AFX, localized in the right temporal region of the scalp, successfully treated with surgical excision. Immunohistochemical staining helps differentiate this tumor from others in the clinical differential diagnosis, including malignant melanoma, squamous cell carcinoma, and other nonmelanocytic spindle cell tumors such as leiomyosarcoma, rhabdomyosarcoma, angiosarcoma, liposarcoma, and dermatofibrosarcoma protuberans. Historically, AFX was believed to be a superficial variant of malignant fibrous histiocytoma (MFH). However, MFH is now considered a more generalized term for a sarcomatous neoplasm of the subcutaneous tissue. The histopathology of MFH shares features with some malignant mesenchymal neoplasms such as liposarcoma, leiomyosarcoma, rhabdomyosarcoma, and angiosarcoma, but can be differentiated using immunohistochemistry and/or electron microscopy. More recently, the examples of MFH that do not exhibit a more specific line of differentiation have been reclassified as undifferentiated pleomorphic sarcoma (UPS). Many authors currently cannot draw a distinction between AFX and UPS. The clinical and histopathological differences between AFX and UPS are often difficult to delineate. It is probable that they represent two poles of the same disease. Surgical excision in the patient we describe resulted in excellent aesthetic results with lack of recurrence in the 7-month postoperative period.

Vitamin D and estrogen receptor gene polymorphisms and the risk of colorectal cancer in Bulgaria.

BACKGROUND AND AIMS: Different epidemiological studies report the protective effect on colorectal cancer (CRC) exerted by vitamin D(3) intake, estrogen replacement therapy, and increase of the risk of microsatellite instability (MSI) in CRC by withdrawal of estrogens. The aim of our study was to search for association between CRC and polymorphisms in estrogen receptor-alpha (ER-alpha) and Vitamin D receptor (VDR) genes. MATERIALS AND METHODS: We analyzed the PvuII and XbaI polymorphisms from the ER-alpha gene and the BsmI polymorphism of the VDR gene in 140 patients with CRC (subsequently divided according to their MSI status) and 94 controls. RESULTS: We have demonstrated that the presence of the PvuII pp genotype increased the risk of developing MSI(+) tumors about three times compared to MSI(-) tumors [odds ratio (OR)=3.09, 95% confidence interval (CI) 0.88-10.91]. The effect of the XbaI xx genotype was similar (OR=2.08, 95% CI 0.49-8.81). Our results for the VDR BsmI polymorphism showed an increased risk for CRC in bb carriers (OR=1.8, 95% CI 0.81-4.05). CONCLUSION: We conclude that PvuII and XbaI polymorphisms in the ER-alpha gene were associated with the risk of developing MSI in CRC patients. The BsmI polymorphism in the VDR gene was linked to the risk of developing CRC.

Novel MLH1 frameshift mutation in an extended hereditary nonpolyposis colorectal cancer family.

AIM: To present novel frameshift mutation c.31delC [p.L11X] in the MLH1 gene identified in an extended Bulgarian hereditary non-polyposis colorectal cancer (HNPCC) family and to analyze the molecular and clinical findings within the pedigree concerning the proposal of adequate individual prophylactic strategy for all mutation carriers. METHODS: The pedigree of the family consists of 42 members in four generations. Search for mutations in the MLH1 and hMSH2 genes was performed in the proband. After PCR amplification of all exons including flanking intronic regions, amplicons were directly sequenced. RESULTS: The mutation was found in nine from the thirteen pedigree members who signed informed consent to participate in the study. In three adenocarcinomas, microsatellite instability and lack of the MLH1 protein expression were detected. The only one tubulovillous adenoma analyzed was microsatellite stable and the MLH1 protein showed an intact staining. CONCLUSION: The newly described mutation c.31delC is HNPCC causative. Besides the typical clinical features of the syndrome, we found a specific pathologic manifestation such as moderate to high differentiated adenocarcinomas of the colon. One of the mutation carriers developed a benign giant cell soft tissue tumor. The primary tumor localizations were frequently extracolonic and detailed yearly gastrointestinal and gynecological examinations have been proposed to the mutation carriers. We emphasize the importance of including the HNPCC genetic counseling and testing as well in the following surveillance of all patients at risk in the services covered by the health insurance in Bulgaria.