Biomedical subjects

Renzo A Zaldivar

Publications and source records attributed to Renzo A Zaldivar.

4 recordsLinked to original sources

PubMed2005

Acute intermittent porphyria presenting as a diffuse encephalopathy.

Although acute intermittent porphyria presents with dramatic neurological findings, the diagnosis is difficult. An 18-year-old woman had a clinical picture of porphyric encephalopathy. Magnetic resonance (MR) imaging demonstrated multiple large contrast-enhancing subcortical white matter lesions, which regressed with glucose and hematin infusions. Diffusion-weighted MR imaging was normal, and MR spectroscopy excluded acute demyelination or tissue necrosis. MR findings of acute intermittent porphyria can differ from those in posterior reversible encephalopathy syndrome by virtue of intense contrast enhancement. Because diffusion-weighted MR imaging and spectroscopy were normal, the lesions are likely caused by reversible vasogenic edema and transient breakdown of the blood-brain barrier.

Adolescent↗

PubMed2004

Primary intraocular lymphoma: clinical, cytologic, and flow cytometric analysis.

PURPOSE: To compare cytologic with flow cytometric results of vitreous biopsy specimens obtained to rule out primary intraocular lymphoma (PIOL). STUDY DESIGN: Prospective noncomparative case series. PARTICIPANTS: Patients suspected of having PIOL who underwent vitreous biopsy were evaluated. METHODS: Patients underwent a standard 3-port vitrectomy and vitreous biopsy to rule out PIOL. Each undiluted specimen was split, and half was prepared for cytologic evaluation with the collodion bag method; the other half was submitted for flow cytometric immunophenotyping (FCI). The diluted specimen was processed as a cell block for cytology. MAIN OUTCOME MEASURES: Final diagnosis based on cytology and FCI. RESULTS: Ten of 14 patients had sufficient specimens for both cytologic and FCI evaluation. Three patients had chronic inflammation confirmed by both methods. Six patients had large cell lymphoma identified by both cytology and FCI. Two of those 6 patients initially had insufficient specimen for FCI. One patient had large cell lymphoma diagnosed cytologically that was initially negative for a clonal population by FCI. All lymphomas were B-cell type. CONCLUSIONS: Cytologic evaluation is an accurate diagnostic technique to evaluate for PIOL. FCI is useful for immunophenotyping PIOL. Multiple biopsies may be required to achieve a diagnosis.

Adult↗

PubMed2004

Metastatic breast carcinoma to the vitreous.

PURPOSE: To evaluate the clinical and pathologic findings in two patients with prior breast carcinoma who underwent diagnostic vitrectomy for vitreous opacities and preretinal membrane. METHODS: The clinical histories and ophthalmic findings in two patients were reviewed. Vitrectomy specimens from the patients were processed by cytospin and standard tissue techniques, stained with hematoxylin and eosin, and examined immunohistochemically for cytokeratins. The original breast carcinoma specimens were reviewed. RESULTS: The vitreous in both patients contained malignant cells with cytologic features consistent with metastatic carcinoma. Immunohistochemical stains were positive for cytokeratins in the cells. The cytologic findings in the vitreous cells resembled the primary breast carcinoma. CONCLUSIONS: Breast carcinoma may metastasize to the vitreous, most likely via the retina. The clinical manifestations include vitreous cell and preretinal membrane.

Aged↗

PubMed2003

Clinicopathologic findings in choroidal melanomas after failed transpupillary thermotherapy.

PURPOSE: To review the clinicopathologic features of eyes enucleated after failed transpupillary thermotherapy. DESIGN: Retrospective review. METHODS: Pathology reports in the L.F. Montgomery Laboratory between 1998 and 2002 were searched for enucleated eyes with choroidal melanoma that had been treated only by transpupillary thermotherapy (TTT) prior to enucleation. The clinical features of the patients, including ultrasonography examination, were reviewed and compared with the pathologic findings. RESULTS: Seven eyes from seven patients had been enucleated, representing 8% of eyes treated with TTT at our institute during the period studied. The primary indication for enucleation was tumor growth. The melanomas tended to grow laterally, with minimal if any increase in thickness. Five of the seven eyes histologically demonstrated extrascleral extension, which was detected by ultrasonography prior to enucleation in only one of those eyes. CONCLUSIONS: Choroidal melanoma may continue to grow along a path of least resistance after TTT. The melanoma may extend laterally in the choroid and through emissary canals. Early extrascleral extension may be difficult to detect by ultrasonography.

Adult↗