Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P06126 (CD1a)
 2,221 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Several reports have documented the coexistence of basal cell carcinoma (BCC) with other lesions, including melanoma. This study was performed to determine whether nests of BCC contain benign melanocytes and Langerhans [corrected] cells. Ten cases of BCC were investigated to determine whether benign melanocytes and Langerhans [corrected] cells populate tumor nests. The BCCs were stained with antibodies to cytokeratin AEI/AE3, S-100, HMB-45, Melan-A, and CD1a proteins. We report that all 10 BCCs were populated by dendritic melanocytes distributed at the periphery (5/10 cases) or evenly throughout tumor nests (5/10 cases). Clusters of melanocytes were not identified in any of the BCCs. A total of 9 of 10 tumors showed staining of dendritic Langerhans cells with CD1a. A total of 8 of 10 tumors stained with cytokeratin AEI/AE3; in 6 of the 8 tumors, the staining was focal. We compared these findings with a single example of a BCC and melanoma in situ (MIS) collision tumor in which the cytokeratin AE1/AE3-positive epithelial nests of BCC were populated by a high density of malignant melanocytes that stained with S-100 and HMB-45. Melanocytes were disposed singly and in clusters of two or more cells within BCC tumor nests. We conclude from this study that BCCs are regularly populated by benign melanocytes and Langerhans [corrected] cells. Furthermore, when BCC is infiltrated with malignant melanocytes of MIS, the melanocyte density is higher and clusters of melanocytes can be observed. The significance of these two findings is unclear, as additional cases of BCC MIS collision tumor need to be studied.
 ...
PMID:Basal cell carcinomas are populated by melanocytes and Langerhans [correction of Langerhan's] cells. 1180 3

Distinguishing desmoplastic melanoma (DM) from scar tissue on routine microscopy can be difficult, especially in re-excision specimens, and S100 immunohistochemistry has been recommended as a useful adjunct. The purpose of this study is to evaluate the extent and nature of S100 positivity in scars. In this study, formalin-fixed paraffin archival tissues were evaluated with immunohistochemistry. Ten re-excision specimens of previously biopsied nonnevomelanocytic lesions were immunostained with the S100 and CD57 (Leu 7) antibodies. In 9 of the 10 cases, the scars contained S100-positive spindle cells, but there were no cases with CD57+ cells. Ten re-excised atypical nevi and 10 re-excised melanomas were also immunostained for the S100 protein, and all 20 cases contained S100-positive spindle cells within the scars. There was a trend toward quantitatively more S100-positive spindle cells in these nevomelanocytic re-excisions. To evaluate the nature of the spindle cells, scars from two of the nonnevomelanocytic re-excisions were further analyzed utilizing immunostains for glial fibrillary acidic protein, HMB-45, Melan-A, CD1a, factor XIIIa, and neuron specific enolase. In both scars, neuron specific enolase diffusely stained the fibroblast population, but the remaining immunostains were negative in the scar. The presence of S100-positive spindle cells in scars represents a potential diagnostic pitfall, particularly in the evaluation of re-excision specimens of DM.
 ...
PMID:S100-positive spindle cells in scars: a diagnostic pitfall in the re-excision of desmoplastic melanoma. 1214 9

An 88-year-old white male presented with a rapidly growing skin nodule on the scalp. Clinically, the nodule did not appear unusual for an ordinary cutaneous neoplasm on sun-exposed skin of an elderly white male. Histopathological examination showed sheet-like epithelioid tumor cell growth with a vaguely nested pattern and frank malignant features, resembling malignant melanoma. However, the tumor cells possessed irregularly convoluted nuclei with nuclear groves, frequent multinucleation and fine vesicular cytoplasm, features highly suggestive of histiocytes. Immunohistochemistry studies showed that the tumor cells were diffusely positive for S-100 protein and CD1a and negative for HMB-45, Melan-A, cytokeratin and CD30. The provisional diagnosis of Langerhans cell sarcoma was thus favored. To confirm this diagnosis, electron microscopic examination was performed. Although classic features of histiocytes were readily identifiable, no Birbeck granules could be found upon a thorough search on repeated sections. These results are indicative of the indeterminate cell nature of the tumor. We propose a diagnosis of primary cutaneous indeterminate cell sarcoma for this unusual histiocytic neoplasm. Current classification of histiocytic neoplasms and differential diagnosis are reviewed.
 ...
PMID:Primary cutaneous Langerhans cell sarcoma without Birbeck granules: indeterminate cell sarcoma? 1842 73

Langerhans cell histiocytosis (LCH), especially with an involvement limited to the skin, is a rare entity in adults. In formulating a differential diagnosis of a solitary skin lesion, LCH is rarely considered. Morphologically, cells seen in LCH can mimic those seen in a melanocytic tumor; moreover, they both show S-100 protein reactivity with immunoperoxidase staining. A 63-year-old male presented to a dermatology clinic with a solitary hyperpigmented macule on his right calf. A biopsy specimen showed epithelioid cells within the dermis, singly and in small groups, surrounded and infiltrated by collections of histiocytes and lymphocytes. These cells were diffusely positive for S-100 and negative for Melan-A. A diagnosis of malignant melanoma, spitzoid variant, was rendered, and the patient was sent to our melanoma center for surgical treatment. On histologic examination, some of the lesional cells had reniform, vesicular nuclei with central grooves. Additional immunoperoxidase staining showed strong, diffuse positivity for CD1a, supporting the diagnosis of LCH. LCH is morphologically similar to and can be misdiagnosed as malignant melanoma. It is important to be aware of this pitfall and utilize immunohistochemical and ultrastructural analysis to achieve correct diagnosis.
 ...
PMID:Langerhans cell histiocytosis mimicking malignant melanoma: a diagnostic pitfall. 1880 99