Malignant eccrine hidradenoma.

Hidradenomas are adenomatous tumors of sweat gland origin that are usually benign and can occur in any cutaneous skin surface. When malignant, the tumors have high recurrence rates and are often fatal. Because of their infrequency and clinical ambiguity, hidradenomas are often misdiagnosed as other soft-tissue masses.

Derivation and characterization of an extra-axial chordoma cell line (EACH-1) from a scapular tumor.

Background: Extra-axial chordomas are rare low-grade malignant tumors thought to arise from notochordal remnants in the extra-axial skeleton. Few studies have been done on this neoplasm because of its rarity. In addition, there is a lack of a good in vitro model on which to perform more characterization.

Infantile fibrosarcoma successfully treated with chemotherapy, with occurrence of calcifying aponeurotic fibroma and pleomorphic/spindled celled lipoma at the site 12 years later.

The treatment of infantile fibrosarcoma has traditionally been wide resection. Chemotherapy has been investigated as an adjuvant and primary treatment in cases in which surgery would cause unacceptable morbidity. Recurrences normally occur within a year of completion of the chemotherapy and display the same histology.

Massive osteolysis due to failure of a unipolar endoprosthesis.

Unipolar endoprostheses are commonly used for the treatment of displaced femoral neck fractures in the elderly. Failure due to polyethylene wear, which has been well documented in bipolar endoprostheses, is not a commonly reported problem with unipolar prostheses. We present 2 cases of a particular unipolar design that failed due to polyethylene wear.