Incidence of perineural invasion in histologically aggressive types of basal cell carcinoma.

Basal cell carcinoma is generally an indolent form of skin cancer. Morpheaform, infiltrative, and sclerosing types are more aggressive tumors. The incidence of perineural invasion in aggressive types of basal cell carcinoma has not been previously described. We studied aggressive basal cell carcinomas for the presence of perineural invasion. Between 1995 and 1998, the histopathologic diagnosis of basal cell carcinoma was made on 5,097 specimens at Dartmouth-Hitchcock Medical Center. Of this total, 507 were classified as sclerosing, infiltrative, or morpheaform. Perineural invasion was found in 15 of the 507 cases. Of these 15 cases, 12 were from the face, and 3 from the back; 13 were recurrent, and 2 were primary lesions. The mean age of patients at diagnosis was 71 years. We found 9.9% of all basal cell carcinomas at our institution to be aggressive types. We found an incidence of perineural invasion of 3% in the aggressive basal cell carcinoma types. This incidence approaches that reported by others for cutaneous squamous cell carcinomas.

Pigmented squamous cell carcinoma.

Pigmented squamous cell carcinomas have been reported in the oral and ocular mucosae, but rarely in the skin. We present a case of pigmented squamous cell carcinoma of the forehead and review the current English literature. Pigmented squamous cell carcinoma can be confused with pigmented basal cell carcinomas and melanoma, especially those melanomas associated with pseudoepitheliomatous hyperplasia and should be included in the differential diagnosis of atypical pigmented lesions.

Dermatofibrosarcoma protuberans of the oral cavity.

Dermatofibrosarcoma protuberans (DFSP) is a low grade, malignant spindle cell tumor with an infiltrative growth pattern and a high rate of local recurrence. This tumor's cell of origin is controversial. DFSP usually presents in adult life and is most frequently located on the trunk and proximal extremities. Although 10% to 15% of cases involve the head and neck, this tumor has not been previously described in the oral cavity.

Inhibition of fibril formation in beta-amyloid peptide by a novel series of benzofurans.

A series of benzofuran derivatives have been identified as inhibitors of fibril formation in the beta-amyloid peptide. The activity of these compounds has been assessed by a novel fibril-formation-specific immunoassay and for their effects on the production of a biologically active fibril product. The inhibition afforded by the compounds seems to be associated with their binding to beta-amyloid, as identified by scintillation proximity binding assay. Binding assays and NMR studies also indicate that the inhibition is associated with self-aggregation of the compounds. There is a close correlation between the activity of the benzofurans as inhibitors of fibril formation and their ability to bind to beta-amyloid. Non-benzofuran inhibitors of the fibril formation process do not seem to bind to the same site on the beta-amyloid molecule as the benzofurans. Thus a specific recognition site might exist for benzofurans on beta-amyloid, binding to which seems to interfere with the ability of the peptide to form fibrils.

Cowden's syndrome, Lhermitte-Duclos disease, and sclerotic fibroma.

The authors report a case of Lhermitte-Duclos disease, or dysplastic cerebellar gangliocytoma, in which a cutaneous sclerotic fibroma was found incidentally during the second resection of a recurrent cerebellar hamartoma. The association of Lhermitte-Duclos disease and sclerotic fibroma with Cowden's syndrome led to a dermatologic examination and confirmation of the diagnosis of Cowden's syndrome. The combination of both Lhermitte-Duclos disease and sclerotic fibroma with Cowden's syndrome has not previously been reported. A review of the 15 cases of Lhermitte-Duclos disease associated with Cowden's syndrome shows no significant gender predilection. Sclerotic fibromas, once thought to be specific for Cowden's syndrome, also are reviewed.

Cutaneous fibrous histiocytoma with osteoclast-like giant cells.

We report a case of a rare variant of benign fibrous histiocytoma composed of abundant, multinucleated, osteoclast-like giant cells. Local excision with negative margins is the treatment of choice.

Severely atypical medium-sized congenital nevus with widespread satellitosis and placental deposits in a neonate: the problem of congenital melanoma and its simulants.

We describe a neonate with a highly atypical melanocytic proliferation that arose in a medium-sized congenital nevus, in association with multiple cutaneous satellite lesions and placental deposits. The patient's pathologic findings and benign clinical course to date raise the problem of diagnosis of congenital melanoma and the importance of clinical follow-up to determine the biologic behavior of severely atypical, histologically malignant proliferations in congenital melanocytic nevi.

Optimization of LDV geometry.

An optimal geometrical design procedure for a LDV system is derived. Its geometry is defined by the Gaussian f number of the lens F and the half-angle between the two beams theta. Parameters such as measurement olume size, the total broadening of the Doppler signal, the frequency limit of the processor, and some aspects of the signal strength are expressed in terms of these two variables. These parameters are then plotted as functions of F and theta on a single design chart.