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)

Langerhans cell histiocytosis (LCH) is a neoplastic proliferation of Langerhans cells that occurs in a range of nodal and extranodal sites. Scattered reports of LCH within the thymus exist, typically among children within the setting of multifocal, multisystem disease. Rare cases of isolated LCH involving the thymus have occurred in adult patients with myasthenia gravis. We report a case of unifocal LCH involving the thymus in a middle-aged woman with a history of a resected leiomyosarcoma but no evidence of myasthenia gravis. Computed tomographic scans revealed an anterior mediastinal mass, which was excised and measured 9.0 cm. Histologic and immunophenotypic findings (CD1a, S100, and Fascin positive and CD68 negative) were consistent with LCH. To our knowledge, this is the first example of LCH occurring in a patient with a history of soft tissue sarcoma and one of the rare reported examples of LCH presenting as a large isolated lesion in the thymus of a nonmyasthenic adult.
 ...
PMID:Langerhans cell histiocytosis involving the thymus. A case report and review of the literature. 1282 60

Uterine epithelioid smooth muscle tumors and uterine perivascular epithelioid cell tumors (PEComas) are known to display such a substantial overlap in morphologic and immunophenotypic characteristics that the existence of the latter as a distinct clinicopathologic entity at this location has been called into question. Recent research suggests that the constituent entities of the PEComa family at all anatomical locations, including lymphangioleiomyomatosis of the uterus, uniformly display immunoreactivity for CD1a. The purpose of this study is to determine the proportion of uterine epithelioid smooth muscle tumors that may similarly be CD1a-positive. Representative sections from 18 archived epithelioid smooth muscle tumors of the uterine corpus (6 epithelioid leiomyosarcomas and 12 epithelioid leiomyomas), diagnosed and classified as such based on World Health Organization criteria, were subjected to immunohistochemical stains for CD1a and HMB-45. The epithelioid component of the tissue sections evaluated ranged from 10% to 100% (mean, 70%). Two cases were composed predominantly of cells with overtly clear cytoplasm. All cases were entirely negative for CD1a. Of 18 cases, 1 (5.5%) (an epithelioid leiomyosarcoma) displayed immunoreactivity for HMB-45 in scattered lesional cells that constituted approximately 5% of the overall tumoral volume for the case. All others were HMB-45-negative. Given their rarity, future studies are required to confirm that all PEComas of the uterus are indeed uniformly positive for CD1a. However, if the latter staining pattern is confirmed, our findings herein suggest that CD1a may be a useful immunohistochemical adjunct in distinguishing uterine epithelioid smooth muscle tumors from uterine PEComas.
 ...
PMID:Epithelioid smooth muscle tumors of the uterus do not express CD1a: a potential immunohistochemical adjunct in their distinction from uterine perivascular epithelioid cell tumors. 1899 3

A 64-year-old male farmer presented with a rapidly progressive swelling of the left mandible since 6 months. The swelling was firm to hard, diffuse, nontender, obliterating the vestibule with paresthesia of lower lip. The cone beam computed tomography imaging revealed an ill-defined, moth-eaten radiolucency with destruction of the buccal and lingual cortical plates. The rapid growth and aggressive behavior of the lesion coupled with guidance from the patient's previous reports from the incisional biopsy and fine needle aspiration cytology warranted a mandibular resection. Microscopic examination showed an encapsulated lesion situated in the connective tissue containing a mixture of proliferating spindle-shaped cells arranged in fascicles and round cells infiltrating into the connective tissue stroma and bone. The neoplastic cells exhibited atypical features such as pleomorphism, hyperchromatism and increased mitotic figures with noncleaved nuclei. A working diagnosis of a spindle-cell sarcoma was arrived at with various differentials provided such as fibrosarcoma, rhabdomyosarcoma, leiomyosarcoma, malignant peripheral nerve sheath tumor, Langerhans cell histiocytosis and lymphoma and stating the need for immunohistochemistry to subtype the tumor. The neoplastic cells were negative for Van Gieson's stain and Masson's trichrome. Immunohistochemical analysis performed using desmin, smooth muscle actin, S-100 and CD1a in a bid to determine the phenotype of the tumor and rule out the previously stated differentials were all negative for the lesion. Lymphoid markers such as leukocyte common antigen and CD20 (cluster differentiation marker for B-cells) showed positivity in spindle-shaped cells as well as round cells indicating the tumor to be a lymphoproliferative lesion of B-cell type. A final diagnosis of "spindle-cell variant of non-Hodgkin's lymphoma" was rendered based on the immunohistochemical profile.
...
PMID:A rare spindle-cell variant of non-Hodgkin's lymphoma of the mandible. 2719 75