Nevus Lipomatosus Superficialis in a Serous Inflammatory Capsule: A Case Report.

BACKGROUND Nevus lipomatosus superficialis (NLS) is a rare benign hamartomatous lesion characterized by adipocyte infiltration into the dermal layer of the skin. Clinically, there are 2 types of NLS lesions: the classical type and the solitary type. The solitary type of NLS is significantly more common in women, typically presents after age 30 years, and occurs most often in the inner thighs. This lesion is often mistaken for similar cutaneous lesions, including but not limited to acrochordons, fibrolipoma, neurofibromatosis, and lymphangioma. There is limited information in the literature on unique presentations of this rare lesion. CASE REPORT We present a case of a 26-year-old woman worried about a pedunculated papule in a fluid-filled capsule on her right inner thigh. She reported that the lesion doubled in size within 48 h prior to presentation. The lesion was biopsied in the clinic and pathology showed lobules of adipose cells in the dermis surrounded by collagen fibers and vascularity consistent with a diagnosis of inflamed NLS. Upon follow-up 2 weeks later, there were no signs of recurrence. CONCLUSIONS It was hypothesized that the unique presentation of a fluid-filled capsule surrounding a nevus lipomatosus superficialis occurred acutely following torsion of the pedunculated lesion. In addition to the patient's history of frictional rub between the thighs, histologic signs of lymphocytic infiltration in the dermis and edematous stroma supported the claim of torsional origins. The unique presentation of NLS in a fluid-filled capsule is not often discussed in the literature, and we hope this report will aid providers in identifying such lesions in the clinic.

A Rare Case of Prosthetic Joint Infection with Streptococcus gordonii.

BACKGROUND Chronic prosthetic joint infection (PJI) is a devastating complication following total joint arthroplasty, resulting in significant morbidity and mortality. The criterion standard of treatment for chronic PJI is two-stage revision arthroplasty consisting of complete hardware removal, thorough irrigation and debridement, placement of an antibiotic spacer, prolonged intravenous antibiotics based on culture sensitivities, and revision total knee arthroplasty once the infection resolves. The most common organism implicated in chronic PJI is Staphylococcus aureus. CASE REPORT In this report, we have summarized the case of a 75-year-old woman who developed chronic PJI caused by an unusual organism, Streptococcus gordonii, 1 year after a right total knee arthroplasty. S. gordonii is a gram-positive organism that is an oral flora and a colonizer of human teeth. This organism is known to create biofilm on the human teeth, more commonly known as dental plaque. S. gordonii has the ability to travel to extraoral sites and cause infection. It has been found to be a cause of subacute bacterial endocarditis, but it has been rarely described in the literature as a cause of prosthetic joint infection. Treatment of S. gordonii requires a tailored approach. CONCLUSIONS This case report highlights the clinical presentation, diagnosis, and treatment of chronic prosthetic joint infection caused by S. gordonii and identifies a rare cause of PJI that is not well documented in the literature. Streptococcal PJI portends a poorer prognosis, and identification of this organism is crucial for prompt treatment and improved outcomes for PJI.

A Rare Case of Raoultella planticola and Enterococcus casseliflavus Coinfection.

Raoultella planticola, a Gram-negative bacterium, is a nonmotile rod usually found in soil and aquatic environments. It can be found in association with gastrointestinal malignancy. Enterococcus casseliflavus is a rare vancomycin-resistant Enterococcus that is responsible for some bacteremia. Our case describes a unique presentation of colonization with both R. planticola and E. casseliflavus isolated from the biliary stent isolates of a patient with known pancreatic malignancy and concomitant E. casseliflavus bacteremia. This is the first case ever reported of infection with both species.

Noncytotoxic suppression of human immunodeficiency virus type 1 transcription by exosomes secreted from CD8+ T cells.

CD8(+) T cells display a noncytotoxic activity that suppresses transcription of human immunodeficiency virus type 1 (HIV-1) in an antigen-independent and major histocompatibility complex-unrestricted manner. To date, the precise cellular and molecular factors mediating this CD8(+) T-cell effector function remain unsolved. Despite evidence indicating the dependence of the activity on cell-cell contact, the possibility of a membrane-mediated activity that represses transcription from the viral promoter remains unexplored. We therefore investigated whether this inhibition of HIV-1 transcription might be elicited by a membrane-bound determinant. Using a CD8(+) T-cell line displaying potent noncytotoxic HIV-1 suppression activity, we have identified a membrane-localized HIV-1-suppressing activity that is concomitantly secreted as 30- to 100-nm endosome-derived tetraspanin-rich vesicles known as exosomes. Purified exosomes from CD8(+) T-cell culture supernatant noncytotoxically suppressed CCR5-tropic (R5) and CXCR4-tropic (X4) replication of HIV-1 in vitro through a protein moiety. Similar antiviral activity was also found in exosomes isolated from two HIV-1-infected subjects. The antiviral exosomes specifically inhibited HIV-1 transcription in both acute and chronic models of infection. Our results, for the first time, indicate the existence of an antiviral membrane-bound factor consistent with the hallmarks defining noncytotoxic CD8(+) T-cell suppression of HIV-1.