Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0278883 (metastatic melanoma)
 6,224 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The clinical, histopathological, and immunophenotypic characteristics of four cases of malignancy-associated multicentric reticulohistiocytosis (MMR) and one case each of diffuse cutaneous reticulohistiocytosis (DCR) and isolated reticulohistiocytoma (IR), are reviewed. In all four cases of MMR the cutaneous lesions and joint manifestations were judged to be concurrent with the diagnosis of malignancy. Malignancies observed included one case each of pancreatic adenocarcinoma, squamous cell carcinoma of the lung, metastatic melanoma and intraperitoneal grade 4 mucinous adenocarcinoma of uncertain origin. Histologically, all six cases demonstrated the typical changes of a diffuse histiocytic and multinucleated giant cell infiltrate with ground-glass cytoplasm, predominantly in the upper dermis. Immunohistochemical investigation revealed strong cytoplasmic staining with KP-1 (CD68) in all six cases. Prominent membrane staining was noted with leucocyte common antigen (CD45) in four cases (three MMR and one IR), and CD3 in four cases (three MMR and one IR). Weak membrane staining with Leu 22 (CD43) was noted in two MMR cases. UCHL-1 (CD45RO), L26 (CD20), S-100 and BerH2 stains were all uniformly negative. A prominent number of perilesional factor XIIIa-positive dermal dendrocytes were noted in the single case of IR, in contrast with the other five cases. We conclude that MMR, DCR and IR are histopathologically and immunohistochemically similar. The pattern of immunoreactivity observed is consistent with a monocyte-macrophage origin of the infiltrating tumour cells. We emphasize the paraneoplastic association of multicentric reticulohistiocytosis, which we have observed in four of 13 such cases (31%) evaluated at our institution.
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PMID:Malignancy-associated multicentric reticulohistiocytosis: a clinical, histological and immunophenotypic study. 766 44

The diagnosis of metastatic melanoma can be complicated by absent characteristic cytology, melanin, or antigen expression in a suspect tumor, putting the pathologist at risk for incorrectly diagnosing recurrent melanoma while missing a second malignancy. We report a 69-year-old man with a history of acral melanoma, metastatic to inguinal nodes, presenting with an ipsilateral thigh nodule. Histology showed a proliferation of pleomorphic cells in the dermis and subcutis, suspicious for melanoma. S100, Melan-A, and HMB-45 immunohistochemistry were negative. However, microphthalmia-associated transcription factor and CD117 labeled the neoplasm, prompting consideration of a late metastatic melanoma with loss of antigen expression. Subsequent immunolabeling for CD4, CD43, and CD30 and clonal T-cell gene rearrangements enabled the correct diagnosis of cutaneous anaplastic large cell lymphoma. This case illustrates a pitfall in evaluating tumors in patients with known metastatic melanoma, and emphasizes the need for broad-spectrum immunohistochemistry in cases that are not clear-cut.
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PMID:Anaplastic large cell lymphoma: a potential pitfall in the differential diagnosis of melanoma. 2336 72