A large drawing of a nephron for teaching medical students renal physiology, histology, and pharmacology.

The purpose of this study is to see whether a large drawing of a nephron helped medical students in self-directed learning groups learn renal physiology, histology, and pharmacology before discussing clinical cases. The end points were the grades on the renal examination and a student survey. The classes in the fall of 2014 and 2015 used the drawing, but not those of 2012 and 2013. The Charles E. Schmidt College of Medicine at Florida Atlantic University is a newly formed Florida medical school, which enrolled its first class in the fall of 2011. The school relies on self-directed problem-based learning in year 1 and changes over to a case inquiry method in the latter part of year 1 and throughout year 2. At the start of the renal course, each student group received a poster of a nephron with the objective of learning the cell functions of the different nephron parts. During the first year of using the drawing, there was no improvement in grades. After a student suggested adjustment to the drawing, there was a statistically significant difference in the total test score in the second year ( P < 0.001). An unexpected finding was lower grades in all 4 yr in the area of acid-base balance and electrolytes compared with the other four areas tested. In the survey, the students found the drawing useful.

Intraosseous venous malformations of the zygoma: clarification of misconceptions regarding diagnosis and management.

Primary intraosseous venous malformations affecting the zygoma are rare vascular lesions, with only 35 cases reported in the surgical literature. Despite the establishment of the binary classification system, which serves to distinguish vascular tumors from malformations, inappropriate use of the term "hemangioma" to describe a variety of distinct vascular anomalies remains widespread. The authors present 3 cases of zygomatic intraosseous venous malformations and summarize the clinical, radiographic, and immunohistochemical features of these lesions. In each case, an insidious clinical course, combined with the pathognomonic finding of radiating trabeculae on computed tomography, suggests the diagnosis of intraosseous venous malformation. Negative glucose transporter isoform 1 immunoreactivity and histopathological analysis were used to reinforce this diagnosis in 1 patient. Management was individualized in each case, based on symptom complex and aesthetic concern. Given that the therapeutic approach to vascular anomalies is dependent on accurate diagnosis, resolution of semantic matters will optimize the management of these lesions.

Cystic presentation of Ewing's sarcoma with indolent clinico-radiologic behaviour.

Ewing's sarcoma is a high-grade malignant primary bone tumour with aggressive clinico-radiologic features. Rarely, it exhibits a benign pattern, but presentation as a solitary bone cyst in a long bone is rather unusual. The purpose of this paper is to document such a cystic presentation with relatively benign clinico-radiologic course and to review the pertinent literature. A 27-year-old male presented with a pathologic fracture through a radiologically benign appearing solitary bone cyst in the distal tibial metaphysis. The fracture healed on conservative treatment, but the patient presented again a year later with pain and difficulty with weight bearing. Curetting and bone grafting done elsewhere was suggestive of an Ewing's sarcoma, which was later confirmed by a second biopsy. He was treated by standard neoadjuvant chemotherapy followed by wide local excision and reconstruction with an intercalary allograft. At 2 years postoperative follow-up, the patient is without any evidence of local or distant recurrence. Awareness of this atypical presentation is important because it may help in an earlier diagnosis, avoid diagnostic confusion and thus may contribute to improved survival.

Right atrial and pulmonary tumor embolism from renal rhabdomyosarcoma.

A 66-year-old male presented with rhabdomyosarcoma of the right kidney with inferior vena cava tumor thrombus and with tumor emboli to right pulmonary artery and two large fragments of tumor thrombus free floating in the right atrium. The patient underwent right radical nephrectomy and thrombectomy of the right atrium and pulmonary artery. He was discharged on postoperative day 13. To our knowledge this is the first case of large tumor embolism to the right atrium and pulmonary artery from renal rhabdomyosarcoma reported in the literature.

Management of pediatric airway granular cell tumor: role of laryngotracheal reconstruction.

OBJECTIVE: To discuss the role of laryngotracheal reconstruction (LTR) in granular cell tumor (GCT) and to highlight the importance and seriousness of GCT in pediatric airway cases. METHODS: A historical literature review was performed and a GCT case from the University of Miami Pediatric Otolaryngology Clinic is presented to highlight the role of LTR in the treatment of GCT. RESULTS: A case of a GCT of the laryngotracheal airway is reported and the management is discussed. Histological discussion and a review of the literature are included regarding GCT. This case is the third reported in the English literature of two synchronous GCT lesions of the upper airway repaired with a laryngotracheal reconstruction. CONCLUSIONS: In the authors' experience once conservative management consisting of endoscopic debulking has failed the treatment of choice for GCTs of the pediatric airway that are unresectable is a single stage laryngotracheal reconstruction with negative frozen section pathology to assure total wide local excision.

Ulnar nerve component to innervation of thumb carpometacarpal joint.

PURPOSE: Thumb carpometacarpal (CMC) joint arthritis is one of the most common problems addressed by hand surgeons. The gold standard of treatment for thumb CMC joint arthritis is trapeziectomy, ligament reconstruction and tendon interposition. Denervation of the thumb CMC joint is not currently used to treat arthritis in this joint due to the failure of the procedure to yield significant symptomatic relief. The failure of denervation is puzzling, given that past anatomic studies show the radial nerve is the major innervation of the thumb CMC joint with the lateral antebrachial nerve and the median nerve also innervating this joint. Although no anatomic study has ever shown that the ulnar nerve innervates the CMC joint, due to both the failure of denervation and the success of arthroscopic thermal ablation, we suspect that previous anatomic studies may have overlooked innervation of the thumb CMC joint via the ulnar nerve. METHODS: We dissected 19 formalin-preserved cadaveric hand-to-mid-forearm specimens. The radial, median and ulnar nerves were identified in the proximal forearm and then followed distally. Any branch heading toward the radial side of the hand were followed to see if they innervated the thumb CMC joint. RESULTS: Eleven specimens (58%) had superficial radial nerve innervation to the thumb CMC joint. Nine specimens (47%) had median nerve innervation from the motor branch. Nine specimens (47%) had ulnar nerve innervation from the motor branch. CONCLUSIONS: We believe this is the first study to demonstrate that the ulnar nerve innervates the thumb CMC joint This finding may explain the poor results seen in earlier attempts at denervation of the thumb CMC, but the more favorable results with techniques such as arthroscopy with thermal ablation.

Giant cell tumor of the distal femur associated with complete tumor necrosis.

Giant cell tumor is a benign tumor of bone with a predilection for juxta-articular locations. Although not malignant, giant cell tumor often exhibits unpredictable and locally aggressive behavior, and in rare cases can metastasize in the absence of histologic malignancy. Partial tumor necrosis has been infrequently reported within typical giant cell tumor. A 17-year-old girl presented with a right distal femur giant cell tumor associated with complete tumor necrosis on histopathologic analysis. The etiology, prevalence, and implications of complete necrosis in previously untreated giant cell tumor of bone remain unclear, as there are no previously published reports. Despite the complete necrosis evident in our patient, she nonetheless presented with pain. There were no radiographic signs of the necrotic tumor space remodeling with new bone. The patient was treated with standard extended intralesional curetting through a generous cortical window permitting visualization of the entire lesion, and systematic high speed burring and thermal electrocautery ablation of the periphery, followed by micro particulate allogenic bone grafting. At short-term follow-up, she had healed well with no evidence of tumor recurrence. This article presents the first case, to our knowledge, of complete spontaneous tumor necrosis in a previously untreated bone giant cell tumor. Increased understanding of spontaneous tumor necrosis associated with giant cell tumor may help guided future targeted medical and surgical treatment modalities.

Undifferentiated pleomorphic sarcoma of the parotid gland: a rare pediatric case.

BACKGROUND: Undifferentiated pleomorphic sarcoma, or malignant fibrous histiocytoma (MFH) of the head and neck is an uncommon malignancy that is exceedingly rare in the pediatric population. Although MFH was once considered the most common soft tissue sarcoma in adults, recently authors have questioned its existence as a distinct pathologic entity. METHODS: In light of this debate, we present a case of MFH with giant cells involving the parotid gland, and we review its pathology. RESULTS: We describe a 6-year-old male with parotid gland MFH. Diagnosis was fraught with difficulty, typical of this disease. He was treated with a combination of chemotherapy and radiation therapy with a good initial response. CONCLUSION: The classification of MFH has been recently debated. Nevertheless, our case is the second report of pediatric MFH involving the parotid gland. Surgical resection is the preferred treatment, but combined chemoradiation may be necessary in the head and neck region.

Benign multicystic peritoneal mesothelioma in a cesarean-section scar presenting as a fungating mass.

We report a case of a benign multicystic mesothelioma, which presented as a fungating mass through the anterior abdominal wall and arose in a cesarean-section scar without direct peritoneal involvement. A wide local excision was done and the diagnosis was confirmed by histopathology and immunohistochemistry. The postoperative course was uneventful and the patient is asymptomatic at 3 years' follow-up. Although a history of previous abdominal surgery has been reported in a patient with benign multicystic mesothelioma, to the best of our knowledge, there is no report of a benign multicystic mesothelioma arising in a cesarean-section scar or presentation as a fungating skin mass. This unusual presentation may point to a traumatic or inflammatory etiology, although seeding of the wound during the previous surgeries is a more likely postulate. A pertinent review of the literature on benign multicystic mesothelioma is also presented.

Rosai-Dorfman disease presenting as multiple soft tissue masses.

Rosai-Dorfman disease is a rare clinical disorder which may present in many forms. While classically a disease of lymph nodes, soft tissue involvement is fairly common. Soft tissue involvement can occur without any lymphatic or systemic involvement, and may be difficult to diagnose. We describe a patient presenting with multiple soft tissue masses which on biopsy proved to be isolated cutaneous Rosai-Dorfman disease. MR imaging showed two well-defined nonspecific superficial masses that enhanced intensely. Review of the literature suggests that when this disease presents in soft tissue, multiple foci of involvement may be common. Although rare, Rosai-Dorfman disease should be considered in the differential diagnosis of patients presenting with multiple soft tissue masses.