Mast Cell Tumour and Mammary Gland Carcinoma Collision Tumour. Case report and literature review

Collision tumours are the coexistence, at the same venue, of distinct tumours not macroscopically distinguishable and consisting of two independent cell populations without histological admixture. In human medicine, collision tumours in different anatomical sites have been described. In the veterinary literature, few cases exist so far. A 12-year-old female Labrador with a mammary gland nodular lesion was presented for clinical examination. The nodule was surgically removed and underwent histological and immunohistochemical analysis. Histopathological examination revealed two distinct malignant tumours: a mammary gland carcinoma and a cutaneous mast cells tumour. To the author's knowledge, the paper reports the first case of a collision tumour composed of mammary gland neoplasia and mast cell tumour. The rising interest in collision tumours suggests widening their knowledge and setting up a multimodal approach that includes surgery and targeted therapy.

On-Site Availability of Legionella Testing in Acute Care Hospitals, United States

We surveyed 399 US acute care hospitals regarding availability of on-site Legionella testing; 300 (75.2%) did not offer Legionella testing on site. Availability varied according to hospital size and geographic location. On-site access to testing may improve detection of Legionnaires disease and inform patient management and prevention efforts.

Infect Control Hosp Epidemiol 2014;35(7):898–900

Pertactin-negative Bordetella pertussis strains: evidence for a possible selective advantage

BACKGROUND

A recent increase in Bordetella pertussis without the pertactin protein, an acellular vaccine immunogen, has been reported in the United States. Determining whether pertactin-deficient (PRN(-)) B. pertussis is evading vaccine-induced immunity or altering the severity of illness is needed.

METHODS

We retrospectively assessed for associations between pertactin production and both clinical presentation and vaccine history. Cases with isolates collected between May 2011 and February 2013 from 8 states were included. We calculated unadjusted and adjusted odds ratios (ORs) using multivariable logistic regression analysis.

RESULTS

Among 753 isolates, 640 (85%) were PRN(-). The age distribution differed between cases caused by PRN(-) B. pertussis and cases caused by B. pertussis producing pertactin (PRN(+)) (P = .01). The proportion reporting individual pertussis symptoms was similar between the 2 groups, except a higher proportion of PRN(+) case-patients reported apnea (P = .005). Twenty-two case-patients were hospitalized; 6% in the PRN(+) group compared to 3% in the PRN(-) group (P = .11). Case-patients having received at least 1 pertussis vaccine dose had a higher odds of having PRN(-) B. pertussis compared with unvaccinated case-patients (adjusted OR = 2.2; 95% confidence interval [CI], 1.3-4.0). When restricted to case-patients at least 1 year of age and those age-appropriately vaccinated, the adjusted OR increased to 2.7 (95% CI, 1.2-6.1).

CONCLUSIONS

The significant association between vaccination and isolate pertactin production suggests that the likelihood of having reported disease caused by PRN(-) compared with PRN(+) strains is greater in vaccinated persons. Additional studies are needed to assess whether vaccine effectiveness is diminished against PRN(-) strains.