Biomedical subjects
Claudia P Molina
Publications and source records attributed to Claudia P Molina.
Pathologic features of Mycobacterium kansasii infection in patients with acquired immunodeficiency syndrome.
CONTEXT: Mycobacterium kansasii is a slow-growing photochromogenic mycobacterium that may infect patients with human immunodeficiency virus (HIV) late in the course of acquired immunodeficiency syndrome (AIDS). The clinical features of pulmonary and extrapulmonary infections have been described in the literature; however, the pathology of infection has not been adequately addressed. OBJECTIVE: This report describes the pathologic features of 12 cases of M kansasii infection in patients with AIDS. DESIGN: The medical records, autopsy protocols, cytologic material, and histologic material from patients with AIDS and concomitant M kansasii infection at a tertiary-care medical center during 1990-2001 were reviewed. RESULTS: Twelve cases were identified, 6 by autopsy, 5 of which were diagnosed postmortem. Four of the 12 cases had cytologic material and 4 cases had histologic biopsies available for review. Pulmonary infection was most common (9/12), and all patients in whom thoracic lymph nodes were assessed showed involvement (7/7). Abdominal infection was less frequent, with only 1 of 6, 2 of 6, and 2 of 6, demonstrating liver, spleen, and abdominal lymph node infection, respectively. Isolated infections without documented pulmonary infection included brain abscess (n = 1), ulnar osteomyelitis (n = 1), and paratracheal mass (n = 1). Cytologic and histologic material showed a wide range of inflammatory reactions, including granulomas with and without necrosis, neutrophilic abscesses, spindle-cell proliferations, and foci of granular eosinophilic necrosis. The M kansasii bacillus was characteristically long, coarsely beaded, and frequently showed folded, bent, or curved ends. Intracellular bacilli were randomly or haphazardly distributed within histiocytes. CONCLUSION: Mycobacterium kansasii infection produces predominantly pulmonary infection in late-stage AIDS with a high incidence of thoracic lymph node involvement and a much lower incidence of dissemination to other sites. Infection is manifest as a wide variety of inflammatory reactions on cytology and histology; however, the characteristic appearance of the bacillus on acid-fast bacilli stain and its intracellular arrangement in histiocytes can allow a presumptive identification.
Pathologic quiz case: a 37-year-old man with spinal cord compression.
Explore the source record for details and available documents.
Infection by Dipylidium caninum in an infant.
Dipylidium caninum, the dog tapeworm, is a cosmopolitan parasite of dogs and cats and occasionally causes human infection in the United States. Diagnosis is made by observing the characteristic rice grain-like proglottids in stool specimens and the pathognomonic egg packets in the gravid uterus in histologic sections of the parasite. There have been few reported cases of human infection with this parasite, and very little information on the pathology of this zoonotic disease is available in the English language. This report of a case of D caninum infection in a 6-month-old infant highlights the diagnostic features of this disease. To our knowledge, this is the first case to be reported in the American pathology literature during the last 36 years (MEDLINE database, 1966-2002).
Maporal viral infection in the Syrian golden hamster: a model of hantavirus pulmonary syndrome.
Hantavirus pulmonary syndrome (HPS) is a severe and often fatal rodent-borne zoonosis. Maporal (MAP) virus is a newly discovered hantavirus that originally was isolated from an arboreal rice rat captured in central Venezuela. The results of this study indicate that MAP virus in the Syrian golden hamster (Mesocricetus auratus) can cause a disease that is clinically and pathologically remarkably similar to HPS. The similarities include the time course of clinical disease, presence of virus-specific IgG at the onset of clinical disease, subacute pneumonitis, rapid onset of diffuse alveolar edema in the absence of necrosis, hepatic-portal triaditis, mononuclear-cellular infiltrate in lung and liver, widespread distribution of hantaviral antigen in endothelial cells of the microvasculature of lung and other tissues, and variable lethality. These similarities suggest that the MAP virus-hamster system is a useful model for studies of the pathogenesis of HPS and for the evaluation of potential therapeutic agents.
Expression of CD4 on peripheral blood granulocytes. a novel finding in a case of myelodysplastic syndrome in association with t(5;12).
Myelodysplastic syndromes (MDS) are associated with cell maturation defects that can manifest as abnormal surface antigen expression. We describe a patient with refractory anemia with excess blasts, who presented with infection and extensive dysplastic features in peripheral blood granulocytes. The granulocytes expressed CD11b, CD13, CD15, CD33, and CD43. The granulocytes also expressed CD4 antigen. Cytogenetic analysis showed a clonal t(5;12)(q33;p13). The patient improved on antibiotics with partial improvement in the dysplastic features. However, shortly after, the patient experienced paravertebral extramedullary blast transformation followed by a leukemia phase of acute monoblastic leukemia. The patient died a few days later. This is the first report describing anomalous expression of CD4 on granulocytes in MDS. Since the breakpoint on chromosome 12 is near the CD4 gene, which is mapped to 12p12, we hypothesize that dysregulation of the CD4 gene may have occurred resulting in its persistent expression on mature and maturing granulocytes.