Placental site nodule (PSN): an uncommon diagnosis with a common presentation.

Placental site nodule (PSN) is a rare benign lesion of the intermediate trophoblast which is thought to represent incomplete involution of the placental implantation site. PSN usually presents as menorrhagia, intermenstrual bleeding or an abnormal Pap smear. PSN is benign, but it is important to distinguish it from the other benign and malignant lesions like decidua, placental polyp, exaggerated placental site and placental site trophoblastic tumour.

Gene expression of TRK neurotrophin receptors in advanced neuroblastomas in Singapore--a pilot study.

The clinical hallmark of neuroblastoma is heterogeneity. Biologically, ploidy and N-Myc amplification are currently the only 2 features used to define risk group and to determine therapy. Tyrosine kinase neurotrophin receptors (Trks, including TrkA, TrkB, and TrkC) are important in the clinical and biological behavior of neuroblastomas.

Derivation and characterization of human fetal MSCs: an alternative cell source for large-scale production of cardioprotective microparticles.

The therapeutic effects of mesenchymal stem cells (MSCs) transplantation are increasingly thought to be mediated by MSC secretion. We have previously demonstrated that human ESC-derived MSCs (hESC-MSCs) produce cardioprotective microparticles in pig model of myocardial ischemia/reperfusion (MI/R) injury. As the safety and availability of clinical grade human ESCs remain a concern, MSCs from fetal tissue sources were evaluated as alternatives.

Alveolar capillary dysplasia: absence of CD117 immunoreactivity of putative hemangioblast precursor cells.

Alveolar capillary dysplasia is a rare cause of irreversible persistent pulmonary hypertension in newborns resulting from failure of formation of peripheral capillary loops with consequent reduction in the blood-gas barrier. The basic defect in morphogenesis is unknown, although it is postulated that there is a structural abnormality of the hemangioblast precursors of the primitive lung mesenchyme in the septal regions of the developing lung leading to abnormal vasculogenesis. Two cases of alveolar capillary dysplasia evaluated immunohistochemically showed uniform CD117 negativity in the septal interstitial cells forming the pulmonary capillaries.

Perivascular epithelioid cell tumour of the vagina in an 8 year old girl.

Perivascular epithelioid cell tumor (PEComa) is a rare mesenchymal tumor with an unpredictable natural history. We present the first reported case of PEComa of the vagina diagnosed in an 8-year-old girl. This was initially diagnosed on biopsy as an embryonal rhabdomyosarcoma, and the patient underwent 3 cycles of chemotherapy according to the Mesenchymal Malignant Tumour 1989 protocol.