Interferon-γ influences the composition of leukocytic infiltrates in murine lyme carditis.

Interferon (IFN)-γ is present in lesions of patients with Lyme disease and positively correlates with the severity of manifestations. To investigate the role of IFNγ in the development of Lyme carditis, wild-type and IFNγ-deficient C57BL/6 mice were infected with the causative bacterium, Borrelia burgdorferi. Histological analysis revealed no change in the severity of carditis between wild-type and IFNγ-deficient mice at 14, 21, 25, and 28 days after infection. However, a distinct shift in the types of leukocytes within the hearts of IFNγ-deficient mice was observed at 25 days. In the absence of IFNγ, the number of neutrophils in the heart was increased, whereas the number of T lymphocytes was decreased. Bacterial loads within hearts were the same as in wild-type mice. Macrophages secrete chemokines that recruit immune cells, which could contribute to the accumulation of leukocytes in murine Lyme carditis. The ability of IFNγ and B. burgdorferi to activate murine macrophages was examined, and the two stimuli synergistically induced chemoattractants for mononuclear cells (ie, CXCL9, CXCL10, CXCL11, CXCL16, and CCL12) and decreased those for neutrophils (ie, CXCL1, CXCL2, and CXCL3). IFNγ and B. burgdorferi also synergistically enhanced secretion of CXCL9 and CXCL10 by murine cardiac endothelial cells. These results indicate that IFNγ influences the composition of inflammatory infiltrates in Lyme carditis by promoting the accumulation of leukocytes associated with chronic inflammation and suppressing that of cells that typify acute inflammation.

Blue nevus of the colorectal mucosa.

The blue nevus is a well-described benign melanocytic proliferation that generally occurs on the skin. Infrequently, blue nevi are found on mucosal surfaces. The most common location for mucosal blue nevi is the oral mucosa, with reported cases in the sinonasal mucosa and genital tract, as well as in other locations. To our knowledge, blue nevi of the rectal mucosa have not been described. Here, we describe a case of blue nevus arising in the rectal mucosa. Blue nevi are benign melanocytic proliferations with the potential for malignant transformation and should be included in the differential diagnosis of pigmented mucosal lesions of the rectum.

Soft tissue aneurysmal bone cyst: a rare case in a middle aged patient.

Soft tissue aneurysmal bone cyst is a rare entity, with about 20 cases reported in literature, only 3 of which are in patients over 40 years of age. We present a case of a 41 year old Latin American female who presented for evaluation of atraumatic chest pain with radiation to the left shoulder. Her initial workup was negative, including radiographic imaging of the chest and left shoulder. 4 months later, she presented to her orthopedic surgeon with a palpable mass and mild left shoulder pain. Radiographs acquired at that time demonstrated a 7.0 × 5.5 × 6.7 cm mass with rim calcification in the region of the upper triceps muscle. Subsequent CT imaging showed central areas of hypodensity and thin septations, a few of which were calcified. MR evaluation showed hemorrhagic cystic spaces with multiple fluid-fluid levels and enhancing septations. Surgical biopsy was performed and pathology was preliminarily interpreted as cystic myositis ossificans, however on final review the diagnosis of soft tissue aneurysmal bone cyst was made. The lesion was then surgically excised and no evidence of recurrence was seen on a 3 year post-op radiograph. Following description of our case, we conduct a literature review of the imaging characteristics, diagnosis, and treatment of soft tissue aneurysmal bone cyst.

Fine-needle aspiration cytology of unusual germ cell tumors of the mediastinum: atypical seminoma and parietal yolk sac tumor.

A 30-yr-old man presented with a mediastinal germ cell tumor that combined the histologic pattern of seminoma with the immunohistochemical profile of embryonal carcinoma (beta-HCG+/PLAP-). In FNA smears, this atypical seminoma presented as fragile large cells with scanty cytoplasm, vesicular nuclei, irregular and indistinct nucleoli, scattered singly and in loosely cohesive fragments without the characteristic lymphocytic or tigroid background. The cytologic features were more suggestive of a poorly differentiated carcinoma than seminoma, potentially leading to misdiagnosis and mismanagement. The second case was a 51-yr-old female smoker who presented with mediastinal parietal yolk sac tumor with extension to the lung, a rare occurrence, and contrary to the clinical impression of lung cancer with hilar lymph node metastasis. This case illustrates the value of using the unique cytologic features of parietal yolk sac tumor, i.e., the abundant, viscous, stringy metachromatic extracellular hyaline material associated with the tumor cells in reaching the accurate diagnosis.

Biomarkers of cervical dysplasia and carcinoma.

Although cervical cytology screening has decreased the incidence of cervical cancer in industrialized countries, HPV-related cervical disease, including premalignant and malignant lesions, continues to represent a major burden on the health care system. Some of the problems include the potential for either under- or overtreatment of women due to decreased specificity of screening tests as well as significant interobserver variability in the diagnosis of cervical dysplastic lesions. Although not completely elucidated, the HPV-driven molecular mechanisms underlying the development of cervical lesions have provided a number of potential biomarkers for both diagnostic and prognostic use in the clinical management of these women.