Pleomorphic lipoma: case report and literature review.

BACKGROUND: Pleomorphic lipoma is a rare, benign, pseudosarcomatous, soft tissue neoplasm typically involving the subcutis of the neck and shoulder in middle-aged to elderly men. It is characterized histologically by atypical, multinucleated giant cells and grossly as a well-circumscribed mass. Since this neoplasm can resemble a sarcoma, histopathologic diagnosis is critical in preventing unnecessary surgery. OBJECTIVE: To describe a case of pleomorphic lipoma in the neck and to review the clinical and histopathologic characteristics of this neoplasm. METHODS: We present a case report and review of the literature. RESULTS: Local excision to completely extirpate this neoplasm has proven curative at 10 months of follow-up. CONCLUSION: Pleomorphic lipoma is superficially located and may be encountered in a dermatologic setting. Thus the dermatologist should become familiar with its clinical presentation and microscopic appearance.

Immunohistochemical staining for Ber-EP4, p53, proliferating cell nuclear antigen, Ki-67, bcl-2, CD34, and factor XIIIa in nevus sebaceus.

Increased expression of p53 has been found in the majority of basal cell carcinomas (BCCs). The pattern and intensity of this staining, as well as staining for proliferation antigens, seems to correlate with behavior of histologic subtypes of BCC. Nevus sebaceus (NS) is considered a hamartoma. Multiple epithelial neoplasms do arise in NS, and, rarely, they show an aggressive biologic behavior. Significant numbers of these neoplasms, however, have areas of basaloid hyperplasia that are often reported as BCC. Although morphologically similar to BCC, the mechanism underlying the development of these areas has not been investigated, so we sought to evaluate the expression of Ber-EP4, p53, proliferating cell nuclear antigen, Ki-67, bcl-2, Factor XIIIa, and CD34 in areas showing basaloid hyperplasia, arising in NS. We performed immunohistochemical stains for Ber-EP4, p53, proliferating cell nuclear antigen, Ki-67, bcl-2, Factor XIIIa, and CD34 on seven cases of NS with areas of basaloid hyperplasia. All of the eight cases of NS showed diffuse positive membrane staining for Ber-EP4 and negative nuclear staining for p53. Proliferating cell nuclear antigen and Ki-67 staining was only slightly increased in the areas of basaloid hyperplasia, compared with the surrounding epidermis and with areas of the epidermis peripheral to the hamartomatous proliferation, and bcl-2 was only focally positive. Factor XIIIa-positive cells and CD34-positive vascular endothelial cells were increased within the subjacent dermis, a pattern suggestive of follicular differentiation. Our findings suggest that even though areas of basaloid hyperplasia in NS are morphologically similar to BCC, they are induced by different stimulatory and molecular mechanisms. These different mechanisms result in expression of immunohistochemical markers more characteristic of benign follicular tumors than of BCC.

Immunohistochemical nuclear staining for p53, PCNA, and Ki-67 in different histologic variants of basal cell carcinoma.

BACKGROUND: Increased expression of p53 has been found in the majority of basal cell carcinomas (BCCs); however, UV-light-induced signature mutations are present in only about 50% of cases. Increased nuclear staining with an immunohistochemical marker of proliferation, proliferating cell nuclear antigen (PCNA), has been correlated with aggressive behavior in BCC. OBJECTIVE: Our purpose was to determine whether there is any relationship between different histologic variants of BCC and their expression of p53, PCNA, and Ki-67. METHODS: We used immunohistochemical stains for p53, PCNA, and Ki-67, in superficial-multicentric, nodular-noduloulcerative, sclerosing, infiltrative, and metatypical BCC, to determine whether the staining patterns differ in these different histologic variants of BCC. RESULTS: Superficial-multicentric BCCs were negative for p53 in four of eight tumors. Nodular BCC showed moderately intense p53 nuclear staining with some peripheral accentuation. PCNA nuclear staining was greater than Ki-67, and PCNA-positive cells were fewer than 10% in nodular BCC. Sclerosing and infiltrative BCC showed intense p53 nuclear staining with peripheral accentuation. PCNA nuclear staining was greater than Ki-67, and PCNA-positive cells were greater than 30% in the majority of these tumors. Metatypical BCCs showed diffuse intense p53 staining. PCNA nuclear staining was greater than Ki-67, and PCNA-positive cells were greater than 30% in all tumors studied. When overlying actinic keratoses showed p53 staining, the staining did not necessarily correlate with the intensity or even the presence of positive staining in the subjacent BCC. CONCLUSION: There are at least four distinctive patterns for staining of p53, PCNA, and Ki-67 that correlate with different histologic variants of BCC.

Forces produced by lip bumpers on mandibular molars.

The purpose of this study was to measure the forces produced by a lip bumper on the mandibular permanent first molars. The forces in a sample of 38 patients were measured bilaterally with specially designed gauges at rest but with their lips lightly touching, speaking the words church, phone, and pop, and swallowing water. Forces were compared between two types of lip bumpers, i.e., wire or shield, and between various anteroposterior and vertical positions of the lip bumper. The resting forces produced by the wire lip bumper 2 mm anterior to the incisors and vertically positioned at the middle of the incisor crown were 5.93 +/- 4.84 gm for the left side and 4.66 +/- 4.8 gm for the right. The forces were found to be significantly higher when the wire lip bumper was placed 4 mm anterior to the incisors and at a more gingival position, measuring 16.68 +/- 8.7 gm for the left side and 13.88 +/- 8.28 gm for the right. The shield lip bumper had higher forces both at the center of the incisor as well as when it was positioned gingivally. A large individual variation was observed. There were no statistically significant differences in force levels between male and female subjects. Speaking the words church, pop, and phone, produced forces between 11 and 23 gm, using a wire lip bumper. Swallowing produced the highest forces, between 32 and 36 gm. Lip thickness and height did not appear to affect the force levels.