In the following report we describe a medium-sized congenital melanocytic nevus (CMN) on the upper back of a female patient biopsied at 9 days of age. This case is a unique variant of CMN occurring in the neonatal period that mimics malignant melanoma. This is not only because of histologic features such as a large round or ovoid cellular phenotype of melanocytes mimicking melanoma cells but also because of conspicuous angiotropism, a finding not previously reported in such CMN. Immunostaining for blood and lymphatic vessels demonstrated angiotropism of melanocytes about blood vessels but not lymphatics. We have already emphasized the significance of angiotropism as a marker of extravascular migratory metastasis (EVMM) of melanoma. EVMM, a process by which tumor cells migrate along vessels and other tracks, has striking parallels with the migration of embryonic stem cells from the neural crest. Thus we propose, because angiotropism is a common finding in CMN and metastatic melanoma, that (1) such pathways of cellular migration may result in the genesis of CMN and other melanocytic neoplasms; and (2) the dysregulation of such embryonic pathways may result in the retrograde migratory phenomena of melanoma as already described. In summary, extravascular cellular migration of melanocytes seems to be fundamental for melanoma (perhaps other cancer) metastasis but also hypothetically may be important for the development of other melanocytic lesions such as CMN and requires further investigation.

The pathogenesis of central nervous system complications in primary Sjögren's syndrome (CNS‐SS) is unknown. In order to determine whether patients with active CNS‐SS have cerebrospinal fluid (CSF) abnormalities indicative of CNS inflammation, CSF analyses from 30 patients with active CNS‐SS (SSA) were contrasted with those from 20 SS patients without CNS involvement (SSI) and 20 patients with systemic lupus erythematosus and active CNS disease (SLEA). Elevations of total protein concentration, IgG concentration, IgG to total protein ratio, and IgG index were observed in patients with SSA, but not in those with SSI. Agarose gel electrophoresis results were abnormal, with 1 or more bands, in 25 of 29 SSA patients (86%), but in only 3 of 18 SSI patients (17%). Similar, but less striking, CSF abnormalities were seen in a minority of SLEA patients. Fifteen SSA patients (50%) had transient, mild‐to‐moderate CSF pleocytosis, while only 1 SSI patient and 2 SLEA patients had similar findings. Cytologic findings were abnormal in 18 SSA patients (60%); these included atypical mononuclear cells, lymphoblastoid cells, and plasma cells. The presence of immuno‐competent cells and evidence for the intrathecal synthesis of IgG within the CSF of SSA, but not SSI, patients provide diagnostic parameters which are indicative of active disease and which can be monitored serially during therapy.