Mucocutaneous pigmented macule as a result of zinc deposition.

BACKGROUND: Mucocutaneous depositions of various metals such as silver, lead, gold, arsenic, mercury, iron, and bismuth have been previously published. Heavy metal deposition typically occurs in the setting of either prolonged topical application to intact skin, topical application to eroded or ulcerated skin, as a result of either parenteral administration, or due to penetrating traumatic exposure. METHOD: We report a unique case of mucocutaneous pigmentation occurring in a snow skier after topical application of a zinc-containing sunblock. Formalin-fixed paraffin-embedded tissue was utilized for electron microscopy. RESULT: Backscatter electron imaging and energy dispersive spectroscopy revealed that the dominant metal present was zinc. CONCLUSIONS: Mucocutaneous deposition of metals is enhanced by damage to the surface epithelium. Metal-containing topical agents, although commonly used, may rarely result in a permanent pigmentary alteration. We believe similar cases of mucocutaneous deposition of zinc exist; however, as these may be currently misdiagnosed as amalgam tattoos, the true incidence of this disorder is presently undefined.

Analysis of thyroid transcription factor-1 and cytokeratin 20 separates merkel cell carcinoma from small cell carcinoma of lung.

Merkel cell carcinoma needs to be separated from small cell carcinoma metastatic from visceral sites to skin. Pulmonary small cell carcinoma is the most common primary site of small cell carcinoma. We evaluated the immunophenotypic characteristics of 21 Merkel cell carcinomas and 33 small cell carcinomas of lung using thyroid transcription factor-1 and cytokeratin 20. Thyroid transcription factor-1 was 100% specific for the diagnosis of small cell carcinoma of lung associated with a diagnostic sensitivity of 85%. Cytokeratin 20 was present in 95% of Merkel cell carcinomas; however, 33% of small cell carcinoma of lung were also positive. Both antibodies typically demonstrate diffuse and intense staining of their respective tumor cells. We conclude that thyroid transcription factor-1 is a sensitive and specific marker for small cell carcinomas of lung and that a combination of thyroid transcription factor-1 and cytokeratin 20 is indicated to assist in the differentiation of metastatic small cell carcinoma of lung from merkel cell carcinoma.

Cutaneous malignant melanoma associated with extensive pseudoepitheliomatous hyperplasia. Report of a case and discussion of the origin of pseudoepitheliomatous hyperplasia.

We report a case of cutaneous malignant melanoma associated with extensive pseudoepitheliomatous hyperplasia. Pseudoepitheliomatous hyperplasia may mimic squamous cell carcinoma and may complicate the diagnosis of cutaneous melanoma. This diagnostic pitfall is important to both recognize and be cognizant of, so as to avoid diagnostic errors. The observation of the pseudoepitheliomatous hyperplasia, in this case with an extensive proliferation of eccrine ducts, provides further evidence that cutaneous pseudoepitheliomatous hyperplasia arises within the eccrine apparatus.

Postoperative pressure-induced alopecia: report of a case and discussion of the role of apoptosis in non-scarring alopecia.

We report a case of postoperative pressure induced alopecia in a 21-year-old black female after multiple intraoperative procedures. The histopathology is distinctive and demonstrated features in common with trichotillomania and alopecia areata, including the presence of pigment casts, catagen follicles, melanophages and apoptotic bodies. External hair manipulation is considered the primary event in the etiology of pigment casts, however, our present case demonstrated numerous pigment casts despite a complete lack of evidence of external hair manipulation. We performed pattern analysis and in situ end-labeling in 19 cases of non-scarring alopecia. Pigment casts were seen in postoperative alopecia (1 case), alopecia areata (1 case) and trichotillomania (5 cases). These forms of alopecia have in common the sudden termination of the anagen phase of the hair cycle. When the anagen portion of the hair cycle is prematurely disrupted hairs enter into catagen. Pigment casts may represent a non-specific reaction pattern of follicles that are suddenly transformed from anagen to catagen. We therefore propose that hair manipulation is not uniquely responsible for the formation of pigment casts. The primary pathophysiology resulting in the formation of pigment casts more correctly reflects the sudden termination of the anagen phase of the hair cycle.

Interleukin 11 reduces apoptosis in UVB-irradiated mouse skin.

BACKGROUND: UVB radiation, the major cause of skin cancer, causes apoptosis in the skin, characterized by the appearance of 'sunburn cells'. Interleukin 11 (IL-11) has been shown to protect cells in the gastrointestinal system from chemotherapy and radiation-induced death. OBJECTIVE: To determine whether exogenous IL-11 has any effect on the UVB-induced apoptosis of cutaneous tissues. METHODS: Mice were injected with IL-11 or vehicle control prior to irradiation, and TUNEL assays were performed on paraffin-embedded tissue sections at various times after irradiation. RESULTS: Exogenous IL-11 protects epidermal keratinocytes, epithelial cells of the hair follicles inflammatory cells and fibroblasts in the dermis from UVB-induced apoptotic death. CONCLUSION: These findings suggest that IL-11 may play a role in the general homeostasis of the skin.