Fine-needle aspiration and surgical pathology of infectious lesions. Morphologic features and the role of the clinical microbiology laboratory for rapid diagnosis.

There has been a renewed interest in the use of imprint smears at the time of frozen section in surgical pathology and FNA biopsy for the diagnosis of infectious disease because of the increasing need for rapid diagnosis of opportunistic infections in immunocompromised patients. Moreover, the use of FNA biopsy for the evaluation of superficial and deep masses has become more widespread. The critical step in the FNA biopsy and in evaluation of imprint smears from surgical specimens is immediate interpretation of the slides that have been stained by rapid methods as the Diff-Quik technique. This quick interpretation can identify as infectious case that may need ancillary studies such as a separate pass or more tissue for microbiologic examination and special stains on the aspirated smears, sections, or cell block. An infectious case may be suspected when the basic cytologic inflammatory patterns are identified including acute inflammation, chronic inflammation, granulomatous inflammation, or necrosis. There have been numerous reports describing the cytomorphologic features of several organisms seen in FNA and tissue specimens. The pathologist also needs to be aware of the potential for a false-negative diagnosis of neoplasms in those lesions having a prominent inflammatory component as well as the potential for false-positive diagnosis of malignancy when inflammatory atypia and a repair reaction is present. The interaction of anatomic pathologists and clinical microbiologists is essential for appropriate workup of specimens with an infectious disease etiology. Thus, pathologists need to be well versed in both the anatomic and clinical pathology features of infectious diseases. Finally, those involved with FNA biopsy and handling of surgical pathology specimens should use universal precautions, since all patients are potentially infectious with the HIV virus and other communicable agents.

Fatal iatrogenic salicylate intoxication in a long-term user of enteric-coated aspirin.

A 64-year-old woman, who was taking long-term enteric-coated aspirin therapy for rheumatoid arthritis, was prescribed approximately twice her normal dosage (7.1 g daily) during a ten-day convalescence following surgery. Although she presented with features mimicking sepsis, biochemical analysis, ie, a spuriously high carbon dioxide content, suggested salicylate intoxication (admission salicylate concentration, 5.13 mmol/L). She died on the third day after admission. Autopsy showed no major source of infection except for bronchopneumonia. Long-term users of a high-dose aspirin are at risk for potential salicylate intoxication. The metabolism of salicylate, particularly its excretion kinetics, can make small upward dosage adjustments hazardous. Salicylate has widespread metabolic effects that can mimic other medical conditions, leading to delayed diagnosis of salicylate intoxication. Increased mortality and morbidity may result.

Evaluation of the efficacy of reincubation and subsequent subculture of initially positive blood cultures in the detection of additional clinically significant isolates.

Polymicrobial bacteremias are associated with higher mortality than are unimicrobial bacteremias, and their incidence appears to be increasing. Other researchers have recently shown that the prevalence of polymicrobial bacteremias may be underestimated when blood cultures are not evaluated further after identification of an initial isolate. We investigated this possibility by reincubating and further subculturing blood cultures initially positive for a single organism. We failed to show a clinically important increase in recovery of multiple isolates.

Multiple endobronchial granular cell myoblastomas discovered at bronchoscopy.

Granular cell myoblastoma is an uncommon benign tumor. Most cases of endobronchial involvement are detected as they become symptomatic. Multiple tumors of the bronchial tree are quite rare, having been reported infrequently in the English literature. The authors report a case with two-year follow-up, which is unique in that the tumors were asymptomatic and were discovered incidentally at bronchoscopy.

Septic arthritis caused by Kingella kingae.

A normal part of the oral flora, Kingella kingae has seldom been recognized as the cause of serious clinical infections. We report a case of documented septic arthritis caused by K. kingae in an otherwise healthy infant. We suggest that it may be more common than thought based on the general unfamiliarity with this organism and the fact that several dozen clinical isolates have been identified by reference laboratories.

Absence of stainable bone marrow iron in hemochromatosis.

Stainable bone marrow iron was absent from two patients who were found at autopsy to have hemochromatosis. Bleeding could have accounted for the absence of marrow iron in one patient, but there was no evidence of blood loss in the other. Both had cirrhosis and heavy iron deposits in the liver parenchyma. It is suggested that in patients with hemochromatosis and hepatic cirrhosis, absorbed dietary iron is ultimately taken up by the liver at the expense of the erythron, resulting in gradual depletion of marrow stores. A postulated mechanism is that the shunting of portal blood around the liver circumvents some iron-liver interaction that directs absorbed dietary iron to the erythron.

The occurrence of eschars in Rocky Mountain spotted fever.

Two patients with fatal, laboratory-confirmed Rocky Mountain spotted fever (RMSF) were noted early in their course to have a skin lesion characteristic of a rickettsial eschar. Postmortem immunofluorescent and histopathologic studies demonstrated that the lesions were sites of extensive contiguous infection by Rickettsia rickettsii with associated injury to numerous local blood vessels. Rickettsial vasculitis and occlusive luminal thrombosis were associated with dermal and epidermal coagulative necrosis forming the eschars. Both eschars were noted to be the sites of a bite. In one case the arthropod was identified as a tick. The clinical importance of the search for an eschar in a patient suspected of having RMSF is that diagnostic skin biopsy immunofluorescent demonstration of R. rickettsii may be performed prior to the onset of the rash.

Adenoid cystic carcinoma of the minor salivary glands metastatic to the hand.

An unusual case of adenoid cystic carcinoma of the minor salivary glands of the nasal cavity metastasizing to the hand is presented. The problem of differentiating this lesion from the sweat gland tumor is described and the assistance of special stains is pointed out.

Metastasis of a rectal carcinoid to the posterior fossa.

We report the metastasis of a rectal carcinoid to the dura mater of the posterior fossa. The clinical presentation was unusual because of a 10-year latent period between resection of the primary rectal tumor and symptoms and signs of the posterior fossa metastasis; the radiological findings were atypical of a metastasis. Gastrointestinal carcinoids, apudomas, and the concept of the APUD endocrine cell family are reviewed.

Neisseria sicca endocarditis: report of a case and review of the literature.

A rare case of bacterial endocarditis caused by Neisseria sicca is reported. Review of the literature revealed only five other cases where sufficient data existed to confirm this particular organism as the etiological agent of bacterial endocarditis.