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The use of alloplastic matrices that mimic the mineral phase of bone has become a viable alternative to current mainstream therapies in dentistry such as allografts and autogenous grafts. Because alloplastic bone substitutes generally have relatively poor osteogenic properties, analyzing their potential as vehicles to deliver growth factors is an important step in assessing methods to enhance their clinical efficacy. The aim of these studies was to treat beta-tricalcium phosphate (beta-TCP) and calcium sulfate (CaSO(4)) with platelet-derived growth factor (PDGF)-BB to enhance the osteogenic capabilities of these materials.In the beta-TCP studies, PDGF-BB adsorption and release were accomplished using (125)I radiolabeled growth factor and non-radioactive human recombinant PDGF at a ratio of 1:300 M. For the adsorption studies, the radiolabeled PDGF-BB/ non-radioactive PDGF solutions with resultant PDGF concentrations of 10(7) and 10(8) M were incubated with beta-TCP from 1 to 120 minutes, and the amount of adsorbed (125)I-PDGF-BB was measured using a gamma counter. Similar adsorption studies were conducted with a 30-minute incubation of beta-TCP with various PDGF concentrations. In vitro release studies were conducted with beta-TCP to which radiolabeled PDGF had been adsorbed as above. Release studies were also conducted with CaSO(4) that was hydrated with the radioactive PDGF solution described above for the TCP studies. In vivo PDGF-BB release from beta-TCP and CaSO(4) was evaluated in a mouse model, where the radioactive PDGF/non-radioactive PDGF-BB treated beta-TCP or CaSO(4) sample was inserted subcutaneously and later removed for radioactive measurement. Proliferation of human osteoblastic cells in the presence of PDGF- treated beta-TCP or CaSO(4) was assessed by (3)H thymidine incorporation.The absorption studies revealed that PDGF-BB was absorbed in a concentration and time-dependent manner to beta-TCP. In the in vitro release studies, approximately 45% of the adsorbed PDGF-BB was released after 10 days. In vivo release from both materials occurred faster than in vitro release. Osteoblastic cells incubated with PDGF-BB-treated matrices showed significantly (P0.05, ANOVA) greater proliferation than with control matrices alone.These experiments demonstrate the feasibility of using PDGF-BB in combination with alloplastic materials such as beta-TCP or CaSO(4) to serve as more effective bone graft materials with enhanced osteogenic properties.

Choriocarcinoma is frequently preceded by a complete mole, ectopic pregnancy, nonmolar intrauterine abortion, and uncommonly by a partial mole. Choriocarcinoma coexisting with or after an otherwise "normal" pregnancy is extremely rare, with an estimated occurrence of 1 per 160,000 pregnancies. We here report a case of a placental choriocarcinoma with no metastases in a full-term intrauterine pregnancy. The patient is a 29-year-old gravida 2 para 1 female, who had an uncomplicated full-term vaginal delivery of a healthy 3030 g female infant. Her current pregnancy was uneventful, and past medical history was significant for an elective termination of pregnancy 2 years ago at 8 weeks of gestation. Routine examination of the placenta showed a gray-tan nodule, measuring 2 cm in the largest dimension, with a papillary cut surface. Microscopically, this nodule was composed of highly atypical cytotrophoblastic cells and multinucleated atypical syncytiotrophoblastic cells, which were positive for beta-human chorionic gonadotrophin by immunostaining. Extensive necrosis and multiple foci of hemorrhage were present. The overall morphologic and immunohistochemical features were diagnostic for choriocarcinoma. Further investigations, including a full body computed tomography scan, showed no lesions suspicious for metastases. The patient is currently asymptomatic and being followed-up with monthly beta-human chorionic gonadotrophin levels, the most recent one being negative. By reporting this case and reviewing the literature, we support the opinion of a recent similar case report that the incidence of placental choriocarcinoma may actually be higher than expected, as placental examination after a normal spontaneous delivery is not routinely performed at most of the institutions.

Giant cell tumors are an uncommon neoplasm; most are found in the long bones, formed by endochondral ossification. This article presents a case of giant cell tumor of the infratemporal fossa, which by radiographic and clinical examination appears to have originated in the squamous portion of the temporal bone.

We report two unusual cases of solitary fibrous tumor (SFT) of minor salivary glands that microscopically mimicked pleomorphic adenoma. One of these lesions presented in the retromolar region and the other in the buccal mucosa. The microscopic features of these two tumors and their intimate relationship with regional mucous minor salivary glands posed a diagnostic challenge. Awareness of the morphological diversity of SFT coupled to a judicious use of appropriate immunohistochemical probes should prove valuable to accurately segregate SFT from pleomorphic adenoma.

Hidradenomas, also referred to as nodular hidradenomas or clear cell hidradenomas (CCH), are benign cutaneous eccrine tumors usually 2–3 cm in dimension. Hidradenomas are relatively common; however, giant forms are rare. We report a case of an 8.0 × 6.0 × 3.0 cm clear cell hidradenoma of the left knee in a 43-year-old man. The tumor was mobile, located above the patellar tendon and was without bony involvement on imaging studies. Grossly, the resected tumor was unencapsulated and tan, with a solid and cystic cut surface showing papillary excrescences on the cyst wall. Microscopically, the tumor cells showed an infiltrative growth pattern at the periphery, however, the tumor cytology was bland and no necrosis or mitoses were identified. The overlying dermis contained hemosiderin pigment deposition and infiltration with eosinophils. Immunohistochemically, tumor cells were positive for cytokeratin, CAM5.2, p53, carcino-embryonic antigen (CEA) and epithelial membrane antigen (EMA), and negative for CD10 and Ki-67. The cytological features of hidradenomas can present diagnostic challenges, as other ‘clear cell’ tumors such as metastatic renal cell carcinoma should be considered. Immunohistochemical studies and differential diagnoses are discussed. Yu G, Goodloe S, D’Angelis CA, McGrath BE, Chen F. Giant clear cell hidradenoma of the knee.

Bisphosphonates consist of a family of pyrophosphate analogues that are currently being used to treat metastatic bone diseases as well as systemic bone diseases such as osteoporosis. There is accumulating evidence suggesting that patients treated with these bisphosphonates can develop, particularly with invasive dental procedures, osteonecrosis of the jaw. This present study investigated the ability of osteoblastic cells obtained from the alveolar bone of patients on long term intravenous bisphosphonate therapy to respond to agents normally involved in bone regulation and repair. The effects of platelet-derived growth factor-BB (PDGF-BB), 1,25-dihydroxycholecalciferol [1,25(OH)2VitaminD3] and parathyroid hormone (PTH) on basic parameters of cell viability, proliferation, and differentiation were studied. Osteoblastic cells from a diagnosed necrotic alveolar bone specimen obtained with consent from a multiple myeloma female patient, and a non-necrotic sample from a breast cancer female patient both on chronic bisphosphonate therapy (zolendronic acid) were successfully cultured. Cells from an alveolar bone specimen obtained from a female donor with no known medical conditions were also studied for comparative responses. The cells were exposed to 1,25(OH)2D3, PDGF, or PTH under various incubation conditions. The osteoblastic cell differentiation marker, alkaline phosphatase activity, was assayed using a biochemical analysis. Cell viability was assessed with an MTT assay which measures mitochondrial activity and cell proliferation with a tritiated thymidine assay. This study on osteoblastic cells grown from a necrotic alveolar bone from a multiple myeloma patient and a non-necrotic sample from a breast cancer patient, both on long term bisphosphonate treatment, suggests that viable cells from the bone are responsive to agents such as PTH, PDGF and 1,25(OH)2D3 with changes in alkaline phosphatase activity, proliferation and viability suggestive of normal osteoblastic cell responses observed in cultures from a donor of the same gender and age, but not on bisphosphonate treatment. This work provides a rationale for clinical studies to further assess whether the osteonecrosis that sometimes develops in patients treated with bisphosphonates, can be controlled or prevented by close attention to the levels of bone/calcium regulatory agents and/or, in some cases, therapeutic intervention with PDGF to restore regenerative processes that may be compromised at the necrotic site.

Metastasis of a cancer to another coexisting tumor is a very rare event. When this occurs, it confers a diagnostic dilemma. So far, only very few cases have been reported regarding primary squamous cell carcinoma metastatic to lymph nodes replaced by chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL), most of which were metastasis from primary skin cancers. Here we present a rare case of squamous cell carcinoma of lung metastatic to CLL/SLL-involved mediastinal lymph node. The patient was an 82-year-old male who had a history of CLL/SLL and recurrent stroke. His disease has been stable with a white cell count maintained around 60,000 for the previous 3 years without medication. He presented with left-sided facial droop, confusion and slurred speech with a white cell count of 110,000. CT Scan performed recently showed a 2.6 cm right lung mass with enlarged bilateral hilar and mediastinal lymph nodes. Mediastinal lymph node biopsy was performed and sent for frozen section. Frozen section was misinterpreted as “negative” due to diagnostic difficulty. On permanent sections, aggregates of cohesive epithelioid cells (Figure 1) were found in a background of homogenous population of small lymphocytes. The normal architecture of lymph node was effaced (Figure 5). The epithelioid cells showed increased nuclear/cytoplasm ratio, clumpy chromatin, and were positive for CK5/6 (Figure 2) and negative for BerEp4, Mucicarmine (Figure 2) and TTF-1 (Figure 1). The small lymphocytes in the background were positive for CD5, CD20 and CD23 (Figure 6-8), and negative for CD3. These morphological and immunohistochemical features are diagnostic for poorly differentiated squamous cell carcinoma metastatic to a lymph node involved by CLL/SLL. We compared this case with other similar cases available in the literature and discussed diagnostic pitfalls in such situation.

Liposarcomas of the head and neck are rare. There have been 25 previously reported patients in the literature. Four patients with head and neck liposarcomas, recently treated by the Head and Neck Surgery Service, Walter Reed Army Medical Center, are presented. Less than half of reported patients were noted to be living without evidence of disease. Prognosis generally corresponds to the cell type of the tumor. Intraoral, cheek and orbital tumors seem to have a worse prognosis compared to neck tumors. Wide local excision remains the treatment of choice. Advances in surgical techniques have allowed adequate therapy for most head and neck liposarcomas. Advanced lesions should be managed by conservative surgery and radical radiation therapy.

The infection control department at Niagara Falls Memorial Medical Center in Niagara Falls, New York, has developed an innovative approach to decreasing nosocomial infections. By following up on the infections that occur on nursing units, nurses actively work to prevent their occurrence. The approach utilizes nursing accountability, continuing staff education, and documentation, with positive results.

1-hour biopsy specimens of renal allografts were performed in recipients of kidneys from 26 live donor relatives and 13 cadavers. The histological evaluation included light and electron microscopy and immunofluorescence, and, with the possible exception of one specimen, no prognostic indication could be gained from these studies. The 1-hour biopsy will be used as a baseline for subsequent biopsy comparison.