Biomedical subjects

Ashraf M Hassanein

Publications and source records attributed to Ashraf M Hassanein.

5 recordsLinked to original sources

PubMed2005

Peritumoral fibrosis in basal cell and squamous cell carcinoma mimicking perineural invasion: potential pitfall in Mohs micrographic surgery.

BACKGROUND: Perineural invasion (PI) in cutaneous basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) is linked to an aggressive course. We describe a histologic mimic for PI that we termed peritumoral fibrosis (PF). OBJECTIVE: To describe the morphologic changes associated with PF and to determine the incidence of PF and PI in Mohs frozen sections of BCC and SCC. MATERIAL AND METHODS: All cases of BCC and SCC that were treated by Mohs micrographic surgery (MMS) at the Skin and Cancer Center, University of Florida College of Medicine, Gainesville, Florida, and the Center for Dermatology and Skin Surgery, Tampa, Florida, during the period from January 1, 2003, to August 1, 2004, were reviewed for the presence of PI and PF. The latter was defined as the presence of concentric layers of fibrous tissue that either surround and/or were surrounded by tumor formations mimicking perineural or intraneural invasion. Seven hundred six cases of BCC and 264 cases of SCC were surveyed. Eleven cases (10 BCC and 1 SCC) with equivocal areas were destained, and immunohistochemical staining with S-100 protein was performed, proving actual PI in all of these cases. Available original hematoxylin-eosin biopsy slides were correlated with the MMS frozen sections. RESULTS: PF was noticed in 4.5% of SCCs and 5.8% of BCCs. The incidence of unequivocal PI was noted to be 2.6% in SCC and 2.1% in BCC. CONCLUSION: We describe a specific pattern of fibrosis noted in BCC and SCC that we called PF. It shows concentric layers of fibrous tissue surrounding and/or surrounded by tumor formations and resembles carcinomatous perineural and/or intraneural invasion. Moreover, PF was found to be a sensitive marker for PI. Mohs micrographic surgeons should be aware of this phenomenon to avoid triggering unnecessary steps in managing these cases, such as irradiation.

Basal Cell Carcinoma↗

PubMed2004

Sebaceous carcinoma and the T-antigen.

Carcinomas of sebaceous glands are uncommon. They are traditionally classified into ocular and extraocular sebaceous carcinomas (SC). Ocular SC tend to be more common and more aggressive than extraocular SC. However, the latter can occasionally follow a fatal course. Histologically, SC should be classified into 1) SC in situ; 2) SC, infiltrating, low-grade with or without pagetoid spread; 3) SC, infiltrating, high-grade, with or without pagetoid spread; and 4) SC with extraocular and extracutaneous involvement, including metastases. Immunohistochemistry plays a minor role in the diagnosis of SC. Thomsen-Friedenreich (T) antigen can be a helpful tool in differentiating SC (strong T-antigen reactivity in basaloid cells) from other mimicking neoplasms (basaloid cells are T-antigen negative). The histologic differential diagnosis, pathogenesis, and management of SC are reviewed.

Antigens, Viral, Tumor↗

PubMed2003

beta-Catenin is expressed aberrantly in tumors expressing shadow cells. Pilomatricoma, craniopharyngioma, and calcifying odontogenic cyst.

We studied the beta-catenin immunohistochemical profile in tumors expressing shadow cells: pilomatricoma, 10 cases; calcifying odontogenic cyst, 6 cases; and craniopharyngioma, 9 cases. There was strong membranous, cytoplasmic, and nuclear staining of the immature basaloid cells in all of these tumors. Shadow cells were negative in all tumors. It has been documented that rising levels of free beta-catenin drive the formation of complexes with T-cell factor/lymphoid enhancer factor (TCF-Lef) and up-regulate the wingless-Wnt cell-cell signals. The end result is an abnormality of beta-catenin degradation and, thus, a buildup of free beta-catenin in the cytoplasm and/or nucleus, resulting in the stimulation of cellular proliferation and/or inhibition of cell death. beta-Catenin seems to have an important role in the oncogenesis of these tumors. The similar pattern of keratinization in these tumors and the similar pattern of beta-catenin immunoreactivity in the cytoplasm and the nucleus are important findings. It seems that the activation of a common cellular pathway, namely Wnt-beta-catenin-TCF-Lef, has a role in the pathogenesis of these tumors. The latter could be related to their shared method of keratinization or shared dysfunction of the cellular adhesion complex leading to tumorigenesis.

Craniopharyngioma↗

PubMed2003

Lichen planus actinicus.

Lichen planus actinicus is a photodistributed variant of lichen planus that most often occurs in individuals with dark complexions. Sunlight seems to be a triggering factor in most cases. Several clinical morphologic patterns have been described, and multiple therapies with variable results have been used. The lesions in some patients may remit spontaneously with sun avoidance.

Diagnosis, Differential↗

PubMedDate not supplied

Malignant melanoma associated with lichen sclerosus in the vulva of a 10-year-old.

Malignant melanoma of the vulva in childhood is a rare neoplasm. Lichen sclerosus of the vulva in childhood is also a rare disease. The association of these two rare lesions in the vulva of young girls is extremely rare. We present a 10-year-old white girl with malignant melanoma associated with lichen sclerosus of the vulva. She had dark pigmentation of both the labia minora and posterior fourchette. The inner labia majora and fourchette showed whitish, glistening areas of skin. Histologic examination found mostly an in situ lentiginous/mucosal melanoma with focal invasion to a depth of 0.44 mm in the left upper labium majus. All specimens showed evidence of lichen sclerosus. Partial vulvectomy was performed, and no metastases were detected at the time of treatment. The patient has been disease free for the 12 months after treatment. It is critical for physicians to realize that melanoma can occur in children, and although rare, can occur in the vulva. We feel that lichen sclerosus in this instance may represent a pattern of host immune response to melanoma.

Child↗