显著黑色素合成增加的黑色素瘤(动物型黑色素瘤)超微结构研究报道

Melanoma with prominent pigment synthesis or animal-type melanoma (ATM) is a very rare type of melanoma. Its histogenesis has not been elucidated and ultrastructural features have not been described in human beings. We present an additional case of ATM in a 28-year-old woman with positive sentinel node biopsy and provide the results of electron microscopic studies. Histopathologically, the skin lesion was composed of heavily pigmented neoplastic cells mostly arranged as large sheets, focally also in a nodular growth pattern. After bleaching, the neoplastic cells demonstrated round nuclei with 1 or rarely 2 conspicuous nucleoli and a prominent nuclear membrane and abundant, gray, slate-like cytoplasm. Some cells demonstrated round cytoplasmic inclusions. There was no nuclear pleomorphism, and only a few mitotic figures could be found after extensive search. Multiple areas of necrosis en masse of tumor cells were seen. The lymph node biopsy revealed a complete effacement of the lymph node architecture by the extensive proliferation of hyperpigmented cells in the parenchyma. Immunohistochemically, the same pattern of staining was seen on the bleached and unbleached slides both in the skin and in the lymph node. The neoplastic cells stained positively with MiTF (nuclei), NSE, NKI/C3, tyrosinase (weak), p53, and CD68. S-100 protein, HMB45, Melan A, Mac367, and lysozyme reacted ngatively. Occasional cells (< 1%) reacted with MIB-1. Ultrastructural studies revealed that the neoplastic cells possessed a large, indented nucleus with a prominent nuclear membrane, a single (para) centrally located nucleolus, and peripherally marginated chromatin. The cytoplasm was abundant and contained numerous single melanosomes and rare compound melanosomes. The melanosomes were in stages II to IV of maturation, with a marked predominance of stage II and stage III melanosomes. There was a high number of aberrant melanosomes with a wide variety of configurations. Melanophages were a minor component of the lesion. Our ultrastructural studies provide unequivocal evidence that ATM is a neoplasm of melanosome-producing cells. We also review the literature on ATM.

皮肤低分化毛母质癌肉瘤

We present an unusual case of cutaneous carcinosarcoma with the epithelial component closely resembling nodular basal cell carcinoma, and the mesenchymal component composed of cells constituting extended follicular papillae. A solitary tumor was excised in an 80-year-old man. Histologic sections revealed an ulcerated, asymmetric, poorly circumscribed neoplasm composed of epithelial cells arranged in lobules with peripheral palisading or in a cribriform pattern. The epithelial cells were darkly basophilic with scant cytoplasm and round or oval nuclei with an indistinct chromatin pattern and nucleoli. Nuclei crowding and mitotic figures were observed. Some lobules contained melanin. There were no shadow cells, sebaceous or apocrine glandular differentiation. Each epithelial nodule was surrounded by multiple rows of cells with pale vesicular nuclei and scant cytoplasm. Smaller epithelial aggregations were encircled by these cells concentrically; in larger ones these cells were aligned across a broad front resembling so-called “continuous papillae”. Additionally, numerous small follicular germ-like structures associated with papillae were seen. The cells composing “continuous papillae”showed nuclear pleomorphism, numerous mitotic figures including atypical ones, and nuclear crowding. At foci, the transition fromthe multilayered arrangement of these cells into their diffuse proliferation in the stroma was seen. There were no transitions between the epithelial and stromal component; both were intermingled as though being mutually dependent, with no areas revealing a high-grade tumor or dedifferentiation. Immunohistochemically, the epithelial cell component stained with cytokeratins. The cells of the mesenchymal component tested positive for vimentin and negative for desmin and cytokeratins. The proliferation index (Ki-67)was high in both components. Therewere also a high number of p53-positive cells in both compartments. We propose the term “low-grade trichoblastic carcinosarcoma”for this neoplasm. We are not aware of a similar tumor published in the English literature.

放疗后复发性皮肤基底细胞癌HLA-G的表达

Basal cell carcinoma (BCC) of the skin represents the most common malignancy in the fair-skinned population worldwide. HLA-G is one of the molecules implicated in immunotolerance. To investigate the role of HLA-G in recurring BCCs, we constructed a tissue microarray containing 38 primary BCCs that underwent radiotherapy and 14 secondary BCCs recurring on the primary site after radiotherapy, and evaluated the HLAG protein expression by immunohistochemistry. The HLA-G protein was most frequently expressed in aggressive sclerosing BCCs. Nodular BCC demonstrated the strongest HLA-G expression. Interestingly, tumor infiltrating mononuclear cells (TIMC) expressed the HLA-G molecule in BCCs that showed no recurrence. After comparing primary BCCs and BCCs relapsed after radiotherapy, we observed decreased HLA-G expression on tumor cells and the loss of HLA-G expression on TIMC in relapsed BCCs. After radiotherapy, immunobiology of BCC may change resulting in the down-regulation of HLAG expression on tumor and on tumor-infiltrating cells.

具克隆性的发热性溃疡坏死性穆-哈病:一种皮肤实质性T细胞淋巴瘤?

FebrileulceronecroticMucha-Habermanndisease(FUMHD)is a severe variant of pityriasis lichenoides et varioliformis acuta (PLEVA).PLEVA patients only very rarely have systemic signs; the cutaneous lesions are usually asymptomatic, but may be pruritic and may heal with scarring. FUMHD often starts out as classic PLEVA, but goes on to develop widespread ulceronecrotic lesions and is associated with a high mortality rate. Whether Pityriasis lichenoides chronica (PLC) and PLEVA form a spectrum rather than single entities of clonal lymphoproliferative diseases has been discussed. Recently, it has been proposed that FUMHD, too, is a clonal lymphoproliferative disorder. Here, we report two cases of FUMHD with monoclonal T-cell population, as detected by Southern blot analysis. We propose that clonal FUMHD represents a cutaneous T-cell lymphoma entity.

应用他克莫司成功治疗顽固性慢性光化性皮炎

Therapeutically,chronic actinicdermatitis is a problematic condition. Frequently applied sunscreen usually fails to mitigate the clinical symptoms, and steroids-while efficient-exert many undesired side-effects with prolonged usage. We present a case of chronic actinic dermatitis responding well to topically applied tacrolimus (Protopic.) in combination with chemical and physical UV protection.