instruction:
Given an abstract of a paper, generate a title for this paper such that conveys the key focus of the paper.
question:
Abstract: The authors present an in-depth clinical, radiographic, and pathologic analysis of a 62-year-old man with massive bone reabsorption around the proximal femur in a total hip arthroplasty (THA). The THA was revised 13 years after implantation. Thirty millimeters of calcar resorption was noted radiographically. Evidence of stem bending was present on examination of the femoral implant, and marked wear of the acetabular cup was noted. The pathologic evaluation of removed calcar bone and cement revealed a histiocytic mass invading the bone. Intracellular and extracellular polymethylene debris was noted within the invasive mass. Evidence of fragmented methylmethacrylate cement was also present. The bone-cement interface in the excised calcar region contained segments that showed active bone remodelling around the cement without an interposed membrane. It is possible that this case of calcar resorption began with histiocytic activation and recruitment by polyethylene wear debris followed by active bone lysis. The process may be perpetuated by the fragmentation of cement, as motion occurred at the calcar bone-cement interface, and may represent an extreme example of a process occurring in cases of calcar resorption in general.
answer:
14-year follow-up study of a patient with massive calcar resorption. A case report.

question:
Abstract: In 37 patients with seemingly localized non-Hodgkin's lymphoma of the Waldeyer's ring (WR-NHL), lymphangiography (LAG) and/or gallium-67 scans (Ga-67 scans) were done. Before these procedures, 20 patients were diagnosed as Stage I, and 17 as Stage II. LAG was done for 30, and Ga-67 scans for 32, 25 of whom had both. Five patients (16%) were upstaged to Stage III or IV by Ga-67 scans. Only one (3%) had abnormal LAG findings, in whom Ga-67 scans also showed abnormal accumulation in the para-aortic region. Because of this low positive rate, LAG is not recommended for staging of WR-NHL.
answer:
Value of gallium scans and lymphangiography in non-Hodgkin's lymphoma of the Waldeyer's ring.

question:
Abstract: Light and electron microscopy were used to demonstrate extensive matrix degradation in a failed chymopapain-treated disc as compared with an untreated degenerative control disc. Both specimens contained viable cells with patches of degenerative cells. There was a loss of disc height in the chymopapain-treated disc, but no improvement of symptoms. These results illustrated that even in well-circumscribed cases with documented disc protrusion into the spinal canal, the disc space narrowing following injection may aggravate the symptoms of nerve root entrapment, especially if a low-grade lateral recess stenosis is associated with the disc protrusion. The persistence or aggravation of symptoms probably is related to these anatomic considerations. The low level of enzyme activity in the injected area may or may not be correlated with the clinical response to treatment.
answer:
The effects of chymopapain on prolapsed human intervertebral disc. A clinical and correlative histochemical study.