Hypertrophic pachymeningitis: a rare manifestation of IgG4 related disease

Hypertrophic pachymeningitis (HP) is a rare form of diffuse inflammatory disease that causes thickening of the dura mater. It can involve the cranial or the spinal dura or both. An increasingly well-known symptom of IgG4-related illness, a fibroinflammatory syndrome that may affect almost any organ, is IgG4-related hypertrophic pachymeningitis (IgG4-RHP). It is estimated that IgG4-RHP may account for a high proportion of cases of hypertrophic pachymeningitis once considered idiopathic. Contrast magnetic resonance imaging (MRI) shows pachymeningeal enhancement. Serum IgG4 levels may be elevated but are normal in most patients. However, most patients have elevated cerebrospinal fluid (CSF) IgG4 index. Hence, CSF IgG4 index could serve as a less invasive diagnostic marker of IgG4-RHP. Confirmation of diagnosis is by meningeal biopsy that shows swirling “storiform” fibrosis with lymphocytic infiltrates, obliterate phlebitis and IgG4 positive plasma cells. This case highlights the diagnostic dilemma of IgG4-RHP as gold standard of diagnosis is meningeal biopsy which has many of its own limitations. CSF IgG4 index could be an alternate option for meningeal biopsy when the procedure is contraindicated or uninformative.

Simulation of normal, carrier and affected controls for large-scale genotyping of cattle for factor XI deficiency

An insertion mutation within exon 12 of the factor XI gene has been described in Holstein cattle. This has opened the prospect for large-scale screening of cattle using the polymerase chain reaction (PCR) technique for the rapid identification of heterozygous animals. To facilitate such a screening process, the mutant and normal alleles of factor XI gene, represented by 244- and 320-bp PCR amplified fragments, were individually cloned in Escherichia coli using a multicopy plasmid cloning vehicle to generate pFXI-N and pFXI-M, respectively. The authenticity of the inserts was confirmed by nucleotide sequencing. A nested PCR method was developed, by which PCR amplicons generated from primers with annealing sites on the recombinant plasmids and by flanking the insert were used as templates for amplification of the diagnostic products using factor XI gene-specific primers. An equimolar mixture of both PCR amplicons, originating from pFXI-N and pFXI-M, constituted the carrier control while the individual amplicons were the affected and normal controls. The controls were used as references for in-gel comparison to screen a population of 307 cattle and 259 water buffaloes; the frequency of the mutant allele was found to be 0. No DNA size standards were required in this study. The simulated control DNA samples representing normal, carrier and affected cattle have the potential to help in large-scale screening of a cattle population for individuals that are carriers or affected by factor XI deficiency.

Colonic adenocarcinoma presenting as a cutaneous metastasis in an old operative scar.

Cutaneous metastasis from colon cancer is an uncommon event that usually occurs after identification of the primary tumour and generally indicates diffuse disease. Incisional metastasis occasionally occurs following laparoscopic or open colon cancer resection. However, to the authors' knowledge only one previous case of colon cancer presenting as a cutaneous metastasis in an old operative scar has been reported. We describe a case of colon cancer presenting as a cutaneous metastasis in an old cholecystectomy scar and discuss possible pathophysiological mechanisms.