Entamoeba Histolytica: Updates in Clinical Manifestation, Pathogenesis, and Vaccine Development.

Entamoeba histolytica is the responsible parasite of amoebiasis and remains one of the top three parasitic causes of mortality worldwide. With increased travel and emigration to developed countries, infection is becoming more common in nonendemic areas. Although the majority of individuals infected with E. histolytica remain asymptomatic, some present with amoebic colitis and disseminated disease. As more is learned about its pathogenesis and the host's immune response, the potential for developing a vaccine holds promise. This narrative review outlines the current knowledge regarding E. histolytica and E. dispar and insight in the development of a vaccine.

Biparietal Thinning: Accidental Death by a Fall from Standing Height.

Biparietal thinning resulting in bilateral and symmetrical resorption and loss of thickness of the parietal bones is an uncommon to rare condition in the anthropological and clinical literature. This enigmatic condition of unknown etiology was first reported in the 18th century and has been variously described as a nonmetric trait, anatomical variant, anomaly, and pathology. Biparietal thinning presents grossly and radiographically as oval-shaped depressions in 0.25-0.8% and 0.4-0.5% of individuals and with a higher frequency in females over the age of 60 years. A review of the literature revealed only one example of cranial trauma associated with biparietal thinning and none of fatal trauma associated with this condition. This case reports a rare example of fatal trauma in an elderly man that resulted from a backward fall from a standing height and highlights the increased risk of craniocerebral trauma in individuals with this condition.

Tibial bone metastasis as an initial presentation of endometrial carcinoma diagnosed by fine-needle aspiration cytology: A case report and review of the literature.

Endometrial cancer is the most common gynecologic malignancy in the United States. However, bony metastasis is infrequent and exceptionally rare as the initial presentation. We report a case of a 77-year-old female with a clinically silent endometrial carcinoma who presented with a left tibial metastasis as the first manifestation of her disease. Ours is only the third case diagnosed by fine-needle aspiration (FNA) cytology, and the first to detail the cytomorphologic features of metastatic endometrial cancer to bone. These microscopic findings, including three-dimensional cohesive clusters with cellular overlapping and cuboidal to columnar cells exhibiting low nuclear: cytoplasmic ratios and partially vacuolated cytoplasm, differ significantly from those of endometrial carcinoma on a Papanicolaou test. The tumor bore similarity to the more commonly encountered metastatic colon cancer, but immunohistochemical staining enabled reliable distinction between these entities. A review of osseous metastases of endometrial cancer demonstrates a predilection for bones of the lower extremity and pelvis with a predominance of the endometrioid histologic subtype. In about a quarter of the cases, the bony metastasis was the first manifestation of the cancer. FNA was an effective diagnostic modality for this unusual presentation of a common malignancy. Awareness of this entity and its differential diagnosis is essential for accurate and timely diagnosis.

Understanding acute apophyseal spinous process avulsion injuries.

Apophyseal spinous process avulsion injury was first described in 1941. Since then, there have been sparse additional reports in the literature. The authors report their second case, involving an elite adolescent tennis player. The patient underwent surgical excision of the avulsed spinous process 12 weeks after initial presentation and experienced complete resolution of back pain. The authors provide the first reported histopathological analysis of the avulsion fracture site in the literature for both of their cases. The avulsion injury of the interspinous ligament was characterized by hypercellular fibrocartilage tissue, similar to that seen in severe Osgood-Schlatter's disease. The key physical examination finding in patients with avulsion spinous process fractures is acute tenderness directly over the fracture site that worsens with flexion rather than extension (unlike in spondylolysis). Patients should have routine radiographs, including dynamic flexion-extension views, magnetic resonance imaging, and computed tomography. The authors conclude that after 6 months of nonsurgical management for an athlete, surgical excision should be offered as an alternative. In both of their cases, nonsurgical management failed. Surgical excision offers definitive and simple treatment, as well as early return to athletic activities. Both patients were allowed to return to their competitive level of performance 6 weeks after surgery.

Benign tumors of the spine.

Benign tumors in the spine include osteoid osteoma, osteoblastoma, aneurysmal bone cyst, osteochondroma, neurofibroma, giant cell tumor of bone, eosinophilic granuloma, and hemangioma. Although some are incidental findings, some cause local pain, radicular symptoms, neurologic compromise, spinal instability, and deformity. The evaluation of spinal tumors includes a thorough history and physical examination, imaging, sometimes laboratory evaluation, and biopsy when indicated. Appropriate treatment may be observational (eg, eosinophilic granuloma) or ablative (eg, osteoid osteoma, neurofibroma, hemangioma), but generally is surgical, depending on the level of pain, instability, neurologic compromise, and natural history of the lesion. Knowledge of the epidemiology, common presentation, imaging, and treatment of benign bone tumors is essential for successful management of these lesions.

Tumors and diseases of the joint.

A variety of different diseases affect the synovium, including infection, noninfectious immunologic inflammatory conditions, degenerative arthroses, crystal deposits, trauma, and tumors. Tumors of the synovium are relatively uncommon. Any mesenchymal tumor may arise in the synovium, but most recapitulate its normal counterpart including synoviocytes, blood vessels, fat, and fibrous tissue. These tumors can arise in any synovial lined structures both within joints and in extraarticular locations. Most synovial tumors are benign. Malignant tumors are rare but important to recognize because many are aggressive and must be treated appropriately. Among common nonneoplastic conditions that affect the synovium and surrounding structures are crystal deposits such as monosodium urate crystals, calcium pyrophosphate dihydrate crystals, and hydroxyapatite crystals. These crystal deposits may be asymptomatic or cause severe pain or chronic joint destruction. Their accurate identification is important to guide appropriate therapy.

Giant cell tumor of tendon sheath.

Neoplasms of the hand are not common. Giant cell tumor of tendon sheath (GCTTS) is the most common primary tumor of the hand. Many different theories have recently been proposed as to whether GCTTS is a neoplasm or a localized reactive process. We believe the evidence supports a neoplastic origin. Although the origin is still not proved, the presentation, diagnosis, and treatment of GCTTS have been clear for a long time.