The Reemergence of Measles.

OBJECTIVES: Present-day pathologists may be unfamiliar with the histopathologic features of measles, which is a reemerging disease. Awareness of these features may enable early diagnosis of measles in unsuspected cases, including those with an atypical presentation. Using archived tissue samples from historic patients, a unique source of histopathologic information about measles and other reemerging infectious diseases, we performed a comprehensive analysis of the histopathologic features of measles seen in commonly infected tissues during prodrome, active, and late phases of the disease. METHODS: Subspecialty pathologists analyzed H&E-stained slides of specimens from 89 patients accessioned from 1919 to 1998 and correlated the histopathologic findings with clinical data. RESULTS: Measles caused acute and chronic histopathologic changes, especially in the respiratory, lymphoid (including appendix and tonsils), and central nervous systems. Bacterial infections in lung and other organs contributed significantly to adverse outcomes, especially in immunocompromised patients. CONCLUSIONS: Certain histopathologic features, especially Warthin-Finkeldey cells and multinucleated giant cells without inclusions, allow pathologists to diagnose or suggest the diagnosis of measles in unsuspected cases.

Cutaneous Actinomycosis of the Perineum in an Immunocompetent Man.

ABSTRACT: We present a case of primary cutaneous actinomycosis of unclear pathogenesis. A 30-year-old-man with no significant medical or surgical history presented to the emergency department with a 2-week history of a tender perineal mass. The patient denied trauma or perforating injury to the area. Examination of the area revealed an indurated, nonfluctuant, erythematous papulonodule located 2 cm from the anus. The lesion was unresponsive to oral and topical antibiotics and was therefore excised. The excision specimen revealed a dense mixed infiltrate partially filling the reticular dermis and extending into the subcutaneous fat. The infiltrate surrounded grains of basophilic material with an outer rim of eosinophilic radiating Splendore-Hoeppli material. Within the grains, filamentous bacteria were highlighted with Periodic acid-Schiff and Grocott's methenamine silver. The organisms were gram-positive and acid-fast negative. Given the clinical and histopathologic findings, actinomycosis was diagnosed. Two weeks later, the patient reported resolution of symptoms. The patient was lost to follow-up. This case highlights an unusual presentation of actinomycosis and the crucial role histopathology plays in diagnosis.

A new worm infiltrating the human cornea: A report of three cases.

PURPOSE: To characterize a new species of parasitic nematode that triggers uveitis. OBSERVATIONS: Three previously healthy, relatively young people each contracted a corneal stromal nematode that, upon surgical removal and examination, did not match any known nematodes. Clinical ocular findings included corneal opacification, visible corneal worms, conjunctival injection, and uveitis. CONCLUSIONS AND IMPORTANCE: The three cases presented here represent a previously undescribed parasitic infection of the cornea by an unidentified nematode. These findings may represent a previously unrecognized zoonotic infection from wildlife sources and potentially a newly documented nematode requiring description. Future clinical findings regarding this newly described nematode are needed to further develop our understanding of the disease.

Surgical Pathologic Diagnosis.

Surgical pathology results can play a crucial role in the management of immunocompromised patients. Here we highlight factors that differ between immunocompromised and immunocompetent hosts, such as variation in inflammatory response. Conditions that are covered include drug reactions, disease within solid organ allografts, immune reconstitution inflammatory syndrome, specific immunodeficiency syndromes, neoplasms related to viral infections, and viral, bacterial, fungal, and parasitic infections. Special techniques including immunohistochemistry, in situ hybridization and molecular detection of pathogen nucleic acid from formalin-fixed, paraffin-embedded tissue are discussed.

From the radiologic pathology archives imaging of osteonecrosis: radiologic-pathologic correlation.

Osteonecrosis is common and represents loss of blood supply to a region of bone. Common sites affected include the femoral head, humeral head, knee, femoral/tibial metadiaphysis, scaphoid, lunate, and talus. Symptomatic femoral head osteonecrosis accounts for 10,000-20,000 new cases annually in the United States. In contradistinction, metadiaphyseal osteonecrosis is often occult and asymptomatic. There are numerous causes of osteonecrosis most commonly related to trauma, corticosteroids, and idiopathic. Imaging of osteonecrosis is frequently diagnostic with a serpentine rim of sclerosis on radiographs, photopenia in early disease at bone scintigraphy, and maintained yellow marrow at MR imaging with a serpentine rim of high signal intensity (double-line sign) on images obtained with long repetition time sequences. These radiologic features correspond to the underlying pathology of osseous response to wall off the osteonecrotic process and attempts at repair with vascularized granulation tissue at the reactive interface. The long-term clinical importance of epiphyseal osteonecrosis is almost exclusively based on the likelihood of overlying articular collapse. MR imaging is generally considered the most sensitive and specific imaging modality both for early diagnosis and identifying features that increase the possibility of this complication. Treatment subsequent to articular collapse and development of secondary osteoarthritis typically requires reconstructive surgery. Malignant transformation of osteonecrosis is rare and almost exclusively associated with metadiaphyseal lesions. Imaging features of this dire sequela include aggressive bone destruction about the lesion margin, cortical involvement, and an associated soft-tissue mass. Recognizing the appearance of osteonecrosis, which reflects the underlying pathology, improves radiologic assessment and is important to guide optimal patient management.

From the radiologic pathology archives: ewing sarcoma family of tumors: radiologic-pathologic correlation.

The Ewing sarcoma family of tumors includes osseous Ewing sarcoma, extraskeletal Ewing sarcoma, primitive neuroectodermal tumor, and Askin tumor. They share a karyotype abnormality with translocation involving chromosomes 11 and 22. Histologically, these lesions demonstrate crowded sheets of small round blue cells. Imaging features of osseous Ewing sarcoma often suggest the diagnosis, with aggressive long-bone destruction in the metadiaphysis of an adolescent or young adult and an associated soft-tissue mass. Focal areas of cortical destruction are frequent, allowing continuity between the intraosseous and extraosseous components. This continuity is also commonly seen as subtle channels extending through the cortex at computed tomography or magnetic resonance (MR) imaging, a finding that reflects the underlying pathologic appearance. Extraskeletal Ewing sarcoma commonly demonstrates a nonspecific radiologic appearance of a large soft-tissue mass affecting the paraspinal region or lower extremity. Askin tumor represents extraskeletal Ewing sarcoma involving the chest wall. Imaging typically reveals a large pleural-based mass and associated pleural effusion. Treatment of these tumors is usually a combination of neoadjuvant chemotherapy followed by surgical resection, which may be supplemented with radiation therapy. Imaging, particularly MR, is also vital to evaluate response to neoadjuvant therapy, direct surgical resection, and detect local recurrence or metastatic disease.

Deposition of calcium salts in a case of pulmonary zygomycosis: histopathologic and chemical findings.

We report a case of pulmonary zygomycosis associated with unusual deposition of calcium salt crystals. The patient was a 75-year-old female who had onset of cough and shortness of breath. She was treated for community-acquired pneumonia but died despite intensive therapy. Postmortem examination revealed diffuse alveolar damage and multifocal necrotizing pneumonia associated with herpes simplex infection and invasive zygomycosis. Birefringent particles were seen associated with fungal elements in the lung parenchyma, within bronchial cartilage, and in blood vessel walls. By infrared spectroscopy, the birefringent particles in the pulmonary parenchyma and within bronchial cartilage had spectral characteristics of calcium oxalate dihydrate and calcium oxalate monohydrate, respectively. The birefringent crystals within vascular walls were identified as calcium carbonate. This case documents the chemical composition and location of 3 different calcium salt crystals in pulmonary zygomycosis. It also shows that among pulmonary fungal infections, calcium oxalate deposition is not restricted to aspergillosis.

Borderline tuberculoid leprosy in a woman from the state of Georgia with armadillo exposure.

In the southern and southeastern United States, the 9-banded armadillo is an important reservoir for Mycobacterium leprae, the causative agent of leprosy (Hansen's disease). Here, we describe a woman living in Georgia with borderline tuberculoid leprosy who worked for many years in a garden where armadillos burrowed or were buried. There was no history of foreign travel or known exposure to a person with leprosy. Treatment with 6 once-monthly combined doses of rifampin, ofloxacin, and minocycline was successful.

Fungi as bioweapons.

Fungi cause disease directly by infection or indirectly through mycotoxins. Fungi that are used as weapons might be targeted against humans, livestock, or crops. Humans and animals encounter fungi and mycotoxins through inhalation, ingestion, and contact with skin and mucous membranes. Effective fungal bioweapons would require the ability to cause significant destruction and a means of delivery to target populations or farms. Effective counter measures against fungal bioweapons would be able to prevent or treat this damage. This article describes several potential biological warfare or bioterrorism fungal species and mycotoxins in regard to their biology, epidemiology, potential for weaponization, and the clinical features, prevention, and treatment of the diseases that they cause.