Minimally Invasive Adenocarcinoma of the Lung as Second Malignant Neoplasm Following Pediatric Rhabdomyosarcoma.

Primary pulmonary tumors are extremely rare in the pediatric population; however, sporadic cases of invasive pulmonary adenocarcinoma as a second malignant neoplasm (SMN) have been described in survivors of pediatric cancers. Pediatric patients with rhabdomyosarcoma (RMS) have a particularly increased risk of developing a SMN when compared to the general population, though pulmonary adenocarcinoma has not been previously described in a RMS patient. A 12-year-old female previously treated for stage IV pelvic RMS was found to have a left pulmonary nodule on surveillance computed tomography. The nodule was detected 4.25 years after the completion of treatment, which included resection, chemotherapy, and radiation to the abdomen and pelvis. Wedge resection of the pulmonary lesion was performed with negative margins. Histopathological examination revealed minimally invasive adenocarcinoma. Pulmonary adenocarcinoma may rarely present as a SMN in pediatric cancer survivors. The pathogenesis of this association is not yet entirely clear, but may include chemotherapy-induced mutagenesis and/or genetic predisposition. As pulmonary adenocarcinoma may present as a lung lesion radiographically indistinguishable from metastatic RMS, it should be considered in the differential diagnosis of any pediatric RMS survivor presenting with a new pulmonary nodule, especially in cases with late recurrence.

Conjunctival Lesions Secondary to Systemic Varicella Zoster Virus Infection.

Purpose: To report and present images of a case in which discrete conjunctival lesions developed in the setting of primary varicella zoster virus infection (ie, chickenpox). Methods: Case report and literature review. Results: This report describes a young, unvaccinated male who developed an acutely painful, red eye in the setting of disseminated primary varicella zoster infection. The cutaneous rash was widespread and included lesions on both eyelids. The patient was found to have multiple discrete de-epithelialized lesions involving the palpebral and bulbar conjunctiva. Throughout the disease course, good visual function was maintained and there was no evidence of intraocular involvement. The ocular surface lesions resolved without sequelae after 1 week of treatment with topical antibiotic ointment. Conclusions: Primary varicella zoster infection is an increasingly rare phenomenon in the setting of widespread vaccination. However, unvaccinated or undervaccinated individuals and other at-risk populations remain susceptible to developing severe infections. This case of chickenpox involved discrete conjunctival lesions that resolved without sequelae after conservative treatment with topical antibiotic ointment. While serious ophthalmic complications are uncommon in primary varicella infection, clinicians should be aware of the potential for ocular morbidity in this increasingly rare condition.

Decellularized tissue-engineered heart valve leaflets with recellularization potential.

Tissue-engineered heart valves (TEHV) have been proposed as a promising solution for the clinical needs of pediatric patients. In vivo studies have shown TEHV leaflet contraction and regurgitation after several months of implantation. This has been attributed to contractile cells utilized to produce the extracellular matrix (ECM) during TEHV culture. Here, we utilized such cells to develop a mature ECM in a fibrin-based scaffold that generates commissural alignment in TEHV leaflets and then removed these cells using detergents. Further, we evaluated recellularization with potentially noncontractile cells. A tissue-engineered leaflet model was developed with mechanical anisotropy and tensile properties comparable to an ovine pulmonary valve leaflet. No change in tensile properties occurred after decellularization using 1% sodium dodecyl sulfate and 1% Triton detergent treatment. Cell removal was verified by DNA quantitation and western blot analysis for cellular proteins. Histological and scanning electron microscope imaging showed no significant change in the ECM organization and microstructure. We further tested the recellularization potential of decellularized leaflets by seeding human mesenchymal stem cells (hMSC) on the surface of the leaflets and evaluated them at 1 and 3 weeks in two culture conditions. One medium (M1) was chosen to maintain the MSC phenotype while a second medium (M2) was used to potentially differentiate cells to an interstitial cell phenotype. Cellular quantitation showed that the engineered leaflets were recellularized to the highest concentration with M2 followed by M1, with minimum cell invasion of decellularized native leaflets. Histology showed cellular invasion throughout the thickness of the leaflets in M2 and partial invasion in M1. hMSC stained positive for MSC markers, but also for α-smooth muscle actin in both media at 1 week, with no presence of MSC markers at 3 weeks with the exception of CD90. These results show that engineered leaflets, while having similar tensile properties and collagen content compared to native leaflets, have better recellularization potential.