Andrew Petelin

Systemic lupus erythematosus (SLE) cerebritis versus Listeria monocytogenes meningoencephalitis in a patient with systemic lupus erythematosus on chronic corticosteroid therapy: The diagnostic importance of cerebrospinal fluid (CSF) of lactic acid levels

BACKGROUND Listeria monocytogenes is a motile, aerobic, Gram-positive intracellular bacillus that causes enteritis, meningitis, meningoencephalitis, or subacute bacterial endocarditis. Patients with impaired T-lymphocyte function/cell-mediated immunity are predisposed to intracellular pathogens, e.g., L. monocytogenes. In adults, infection by L. monocytogenes of the central nervous system (CNS) clinically manifests as either acute bacterial meningitis or meningoencephalitis. In patients with systemic lupus erythematosus (SLE) presenting with headache and fever, SLE cerebritis must be differentiated from acute bacterial meningitis by lumbar puncture and cerebrospinal fluid (CSF) analysis. Neuropathogenic viruses are the most common causes of meningoencephalitis. The most rapid and accurate way to differentiate bacterial meningoencephalitis from nonbacterial meningoencephalitis is CSF lactic acid levels. METHODS We present a patient receiving chronic corticosteroid therapy and manifesting SLE and severe L. monocytogenes meningoencephalitis. An early diagnosis of L. meningoencephalitis was achieved by demonstrating a very highly elevated level of lactic acid in his CSF, days before CSF and blood cultures tested positive for L. monocytogenes. RESULTS AND CONCLUSION In this patient, the highly elevated levels of lactic acid in his CSF ruled out both viral meningoencephalitis and SLE cerebritis. The case was complicated by communicating hydrocephalus, and the patient later underwent placement of a shunt. He completed 6 weeks of meningeal dosed ampicillin.

Fever of unknown origin (FUO) due to large B-cell lymphoma: The diagnostic significance of highly elevated alkaline phosphatase and serum ferritin levels

BACKGROUND Determining the cause of fever of unknown origin (FUO) is often a vexing and difficult diagnostic process. In most cases, the signs and symptoms in adult FUOs suggest a malignant, infectious, or rheumatic/inflammatory etiology. The diagnosis of FUO may be narrowed if specific findings are present (eg, hepatosplenomegaly) that limit the diagnostic possibilities. Infectious causes of FUO with hepatosplenomegaly include miliary tuberculosis, typhoid fever, and visceral leishmanosis (kala-azar). However, FUOs with hepatosplenomegaly are most often attributable to malignant neoplasms, ie, Hodgkin lymphoma, non-Hodgkin lymphoma, hepatoma, hypernephroma (renal-cell carcinoma), or preleukemia. METHODS AND RESULTS We present a middle-aged woman with FUO and hepatosplenomegaly. Inpatient nonspecific laboratory findings included a highly elevated erythrocyte sedimentation rate, and elevated levels of vitamin B12, lactate dehydrogenase, angiotensin-converting enzyme, ferritin, and alkaline phosphatase. These individual findings are nonspecific, but together point to a lymphoma. An important test in differentiating malignant from infectious FUOs is the Naprosyn test, and her Naprosyn test was positive, indicating malignancy. A gallium scan suggested a uterine lymphoma. A computed tomography scan revealed hepatosplenomegaly, but the gallium uptake was not increased in her liver and spleen. Uterine and bone marrow biopsies were negative for lymphoma. CONCLUSION We present a case of FUO with hepatosplenomegaly attributable to large B-cell lymphoma as diagnosed via liver biopsy.

Fever of unknown origin (FUO) due to systemic lupus erythematosus (SLE) presenting as pericarditis

Fevers of unknown origin (FUOs) are classified according to the underlying disorder. The 4 main clinical categories of FUOs are infectious, malignant, rheumatic/inflammatory, and miscellaneous disorders. Although malignancy remains the most common cause of FUOs, rheumatic/inflammatory disorders remain important diagnostically and therapeutically. Rheumatic/inflammatory disorders, for example, systemic lupus erythematosus (SLE) presenting as FUO, have become uncommon in recent years because of better serologic diagnostic tests. However, SLE remains a rare but important cause of FUO in adults. SLE may be a difficult FUO diagnosis when a patient presents with fever without joint manifestations as the only symptoms of SLE. During the workup of the patient described in this article, the other causes of pericarditis were ruled out and SLE pericarditis was diagnosed. This is a rare case of an adult FUO with pericarditis as the only manifestation of SLE.

Fever of unknown origin (FUO) and a renal mass: renal cell carcinoma, renal tuberculosis, renal malakoplakia, or xanthogranulomatous pyelonephritis?

Often patients with fevers of unknown origin (FUOs) present with loss of appetite, weight loss, and night sweats, without localizing signs. Some are found to have a renal mass during diagnostic evaluation. In patients with FUOs and a renal mass, the differential diagnosis includes renal tuberculosis, renal cell carcinoma (hypernephroma), renal malakoplakia, and xanthogranulomatous pyelonephritis. A 68-year-old woman presented with an FUO during her diagnostic workup. She manifested an irregularly enlarged kidney on abdominal computed tomography (CT) scan, as well as a highly elevated erythrocyte sedimentation rate of more than 100 mm/hour, an elevated serum ferritin level, and chronic thrombocytosis, which favored a diagnosis of renal cell carcinoma. Renal malakoplakia and renal tuberculosis comprised further differential diagnostic considerations. Microscopic hematuria may be present with any of the disorders in the differential diagnosis, but was absent in this case. An abdominal CT scan was suggestive of xanthogranulomatous pyelonephritis. Because of concerns regarding renal cell carcinoma, the patient received a nephrectomy. The pathologic diagnosis was of xanthogranulomatous pyelonephritis, without renal cell carcinoma.

Infectious mononucleosis-like syndrome probably attributable to Coxsackie A virus infection.

Infectious mononucleosis (IM) is a clinical syndrome most often attributable to Epstein-Barr virus (EBV). Characteristic clinical features of EBV IM include bilateral upper lid edema, exudative or nonexudative pharyngitis, bilateral posterior cervical adenopathy, and splenomegaly ± maculopapular rash. Laboratory features of EBV IM include atypical lymphocytes and elevated levels of serum transaminases. Leukopenia and thrombocytopenia are not uncommon. The syndrome of IM may also be attributable to other infectious diseases, eg, cytomegalovirus (CMV), human herpes virus-6 (HHV-6), or Toxoplasma gondii. Less commonly, viral hepatitis, leptospirosis, brucellosis, or parvovirus B(19) may present as an IM-like infection. To the best of our knowledge, only 2 cases of IM-like infections attributable to Coxsackie B viruses (B(3) and B(4)) have been reported. We present the first reported case of an IM-like syndrome with sore throat, fatigue, atypical lymphocytes, and elevated levels of serum transaminases likely due to Coxsackie A in an immunocompetent adult.

Ehrlichia chaffeensis presenting with bilateral anterior thigh pain (Louria's sign).

Bilateral anterior thigh pain may indicate bacteremia (Lourias Sign). We present a case of Ehrlichiosis due to Ehrlichia chaffeensis whose predominant presenting symptom was localized bilateral anterior thigh pain.

Fever of unknown origin (FUO) attributable to indolent lymphoproliferative disorder due to a plasmacytoma expressing immunoglobulin A.

BACKGROUND The most common categories causing fevers of unknown origin (FUOs) include infective rheumatic/inflammatory disorders and malignancies. Among neoplastic causes of FUOs, lymphomas, hepatomas, renal hypo-nephromas, and hepatomas are the most common. Other malignancies rarely present with FUOs (eg, multiple myeloma). CASE REPORT We describe a 58-year-old man who presented with an FUO accompanied by night sweats, weight loss, and a groin mass. A biopsy of the groin mass (ie, his lymph node) was negative for infectious diseases, rheumatic or inflammatory diseases, and malignancies. Histochemical and immunological studies of the lymph node showed it to contain a plasmacytoma expressing immunoglobulin A (IgA). An immunohistochemical study of the plasma-cell infiltrate demonstrated strong CD138 staining. A bone marrow biopsy was negative for multiple myeloma. CONCLUSION We believe this is the first reported rare case of an indolent, lymphoproliferative disorder attributable to an IgA-secreting plasmacytoma presenting as an FUO.