Biomedical subjects
Rakesh Donthineni-Rao
Publications and source records attributed to Rakesh Donthineni-Rao.
Giant cell tumors: inquiry into immunohistochemical expression of CD117 (c-Kit), microphthalmia transcription factor, tartrate-resistant acid phosphatase, and HAM-56.
CONTEXT: Osteoclast-like giant cells (GCs) in giant cell tumors (GCTs) are thought to derive from a monocyte-macrophage lineage. Microphthalmia transcription factor (MITF) is necessary for osteoclast gene expression and tartrate-resistant acid phosphatase (TRAP) activation; c-Kit plays a role in regulation of MITF. OBJECTIVE: To gain insight into the differentiation of GCTs of bone (GCTBs) and GCTs tendon sheath (GCTTSs) by investigating immunohistochemical staining for c-Kit, MITF, TRAP, and HAM-56 in the GCs and stroma. DESIGN: Immunoreactivity for CD117 (c-Kit), MITF, TRAP, and HAM-56 was studied in 35 GCTBs, 15 GCTTSs, and 5 foreign-body GC controls. RESULTS: Across tumors, MITF and TRAP but not c-Kit were generally expressed in GCs; TRAP was variably expressed in stromal cells. The MITF was expressed more consistently in stromal cells of GCTTSs than GCTBs (P < .001). The GCTBs showed more intense MITF stromal (P < .001) and TRAP GC staining (P = .04) than GCTTSs. HAM-56 staining by stromal cells was associated with MITF stromal staining (r2 = 0.6, P < .001). CONCLUSIONS: Results suggest that MITF and TRAP are expressed during osteoclast differentiation and that a proportion of mononuclear cells in GCTs express the macrophage marker HAM-56. Both GCTBs and GCTTSs show similar patterns of immunohistochemical expression.
Forearm mass in a 31-year-old man.
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Forearm mass in an adolescent.
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Neuropathic arthropathy of the digit: a case report.
We present the case of a 60-year-old diabetic man who developed neuropathic arthropathy in the distal interphalangeal joint of the small finger. Neuropathic arthropathy is uncommon in the upper extremity, and only 2 cases of this condition occurring in the joints of the hand have been reported. The clinical presentation, diagnosis, and treatment options are discussed.
Multiple bone and soft tissue lesions in a 51-year-old woman.
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Proximal tibial segmental prosthetic replacement without the use of muscle flaps.
When doing a proximal tibial prosthetic reconstruction, some surgeons think that the subcutaneous location of the proximal tibia necessitates a gastrocnemius muscle flap for closure and function. In this study, 22 patients with bone tumors had proximal tibial segmental prosthetic replacement using direct reattachment of the patellar tendon to the prosthesis without the use of a muscle flap. Two of 19 patients required reoperation in the postoperative period for hematomas. Both were free of infection or other complications at 24 months mean followup. No other wound complications occurred despite initiation of chemotherapy 2 to 3 weeks after surgery in patients with high-grade malignant tumors (15 of 19). The mean followup was 38.6 months (range, 13-99 months). The patients ranged in age from 15 to 74 years (mean, 39 years). The range of motion achieved postoperatively showed a mean of 97 degrees (+/-16.3 degrees). All patients had full passive extension with a mean extensor lag of 7.5 degrees. The mean Musculoskeletal Tumor Society score was 27.6 (+/- 2.0). These results of patients without muscle flaps compare favorably with published results advocating gastrocnemius flaps for the attachment of the patellar tendon to the prosthesis.
Atypical lipomatous masses of the extremities: outcome of surgical treatment.
Atypical lipomatous tumors occur predominantly in middle-aged patients and often present as painless, slow-growing masses in the extremities. The clinical outcomes of surgically treated superficial or deep atypical lipomas of the extremities were reviewed. Thirty-one patients were included in this study. There were 16 men and 15 women, with an average age of 57 years (range, 32-87 years). The mean followup was 7 years (range, 1-28.8 years). Twenty-five tumors occurred in the lower extremity and six in the upper extremity. Sixteen patients (52%) had a recurrence at an average of 4.7 years after resection. Twelve (39%) patients required additional surgical procedures to treat their tumor. Occurrence of a deep lesion and positive margins at the time of the initial surgery correlated closely with the rate of recurrence and need for additional surgical treatment. Dedifferentiation to high-grade liposarcoma developed in four (13%) patients. Atypical lipomas have a high propensity for local recurrence and a potential for malignant dedifferentiation. Patients with atypical lipomas require careful evaluation, complete surgical excision when possible, and close clinical followup extending beyond 5 years.
Schwannoma of the suprascapular nerve: a case report.
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Fibrous dysplasia.
Fibrous dysplasia is a developmental disorder of bone that can present in a monostotic or polyostotic form. Primarily affecting adolescents and young adults, it accounts for 7% of benign bone tumors. Many of the asymptomatic lesions are found incidentally; the remainder present with symptoms of swelling, deformity, or pain. Fibrous dysplasia has been associated with multiple endocrine and nonendocrine disorders and with McCune-Albright and Mazabraud's syndromes. The etiology remains unclear, but molecular biology suggests a mutation in the G(s)alpha subunit and activation of c-fos and other proto-oncogenes. Fibrous dysplasia has a characteristic radiographic appearance. Most cases do not require intervention, but those that do usually are managed surgically with curettage, bone grafting, and, in some cases, internal fixation. When some intervention is necessary but surgery is not practical, treatment is with bisphosphonates. The prognosis generally is good, although poor outcomes are more frequent in younger patients and in those with polyostotic forms of the disease. The risk of malignant transformation is low.