Are leukocytosis, paresthesia, abnormal arm sensations, back tingling, elevated inflammatory markers, and facial flushing in an adult suggestive of a brain tumor or another condition like Adult-Onset Still's Disease (AOSD)?

Are These Signs of a Brain Tumor?

No, leukocytosis, paresthesia, abnormal arm sensations, back tingling, elevated inflammatory markers, and facial flushing are not typical signs of a brain tumor—these findings strongly suggest Adult-Onset Still's Disease (AOSD) or another systemic inflammatory condition. 1, 2

Why This Presentation Points Away from Brain Tumor

Brain tumors typically present with focal neurological deficits, seizures, headaches with specific patterns (worse in morning, with Valsalva), papilledema, or cognitive changes—not with systemic inflammatory markers and leukocytosis. 2 The combination of leukocytosis with elevated inflammatory markers is fundamentally inconsistent with primary brain malignancy.

Why This Presentation Suggests AOSD

Classic Laboratory Pattern

• Leukocytosis with neutrophilia occurs in 50% of AOSD patients, with counts >15×10⁹ cells/L, and 37% have WBC >20×10⁹. 2, 3
• ESR is elevated in virtually all patients, and CRP is typically raised. 2, 3
• This inflammatory profile is pathognomonic for systemic inflammatory disease, not neoplasm. 1

Neurological Manifestations in AOSD

• Paresthesias and sensory symptoms can occur in AOSD as part of systemic inflammation or peripheral nerve involvement. 4
• While CNS involvement in AOSD is exceedingly rare, peripheral manifestations including myalgias (56-84% incidence) and arthralgias (64-100% incidence) are common. 1, 2
• Generalized body pain and decreased range of motion due to pain in extremities are well-documented AOSD features. 5

Facial Flushing Pattern

• Facial flushing can accompany the fever spikes in AOSD, which occur in 95.7% of patients with temperatures exceeding 39°C. 2, 6
• The evanescent salmon-pink rash predominantly affects proximal limbs and trunk, with rare facial involvement, but flushing during fever episodes is consistent. 2, 3

Critical Diagnostic Algorithm

Step 1: Look for AOSD's Defining Features

• High-spiking fevers >39°C (102.2°F) lasting at least 7 days, typically quotidian or double quotidian pattern with peaks in late afternoon/evening. 1, 2
• Evanescent salmon-pink rash that appears with fever spikes, affecting trunk and proximal limbs. 1, 2
• Arthralgia or arthritis, most commonly affecting knees (69-82%), wrists (67-73%), and ankles (38-55%). 1, 2
• Sore throat (35-92% of patients). 2

Step 2: Confirm Laboratory Abnormalities

• Very high ferritin levels (4,000-30,000 ng/mL, with extreme levels up to 250,000 ng/mL reported) that correlate with disease activity. 1, 2
• Glycosylated ferritin <20% (normal is 50-80%) has 93% specificity when combined with fivefold ferritin elevation. 1
• Marked elevation of serum IL-18 and/or S100 proteins (calprotectin) strongly supports diagnosis. 1

Step 3: Apply Validated Diagnostic Criteria

• Yamaguchi Criteria: Requires 5 criteria with at least 2 major (fever, arthralgia, typical rash, WBC >10,000, negative ANA and RF). 3
• Fautrel Criteria: Includes glycosylated ferritin <20% and PMN >80% for higher specificity. 3

Step 4: Exclude Mimics (Diagnosis of Exclusion)

• Rule out infectious diseases (viral syndromes, bacterial infections), malignancies (leukemia, lymphoma), and other autoimmune conditions before confirming AOSD. 1, 6
• Cultures, serological tests, and potentially bone marrow/lymph node biopsy may be needed. 1

Critical Pitfalls to Avoid

• Do not attribute all symptoms to drug reactions—the rash is pathognomonic and often dismissed as drug allergy. 3
• Do not overlook wrist involvement, as carpal abnormalities distinguish AOSD from rheumatoid arthritis. 3
• Do not miss pancytopenia, which signals potentially fatal macrophage activation syndrome (MAS) requiring urgent intervention with high-dose glucocorticoids, anakinra, ciclosporin, and/or IFNγ inhibitors. 1, 3
• Do not delay treatment—early initiation of IL-1 inhibitors (anakinra) or IL-6 inhibitors (tocilizumab) improves outcomes through a "window of opportunity" effect. 6

When to Consider Neuroimaging

Neuroimaging would only be indicated if focal neurological deficits, seizures, or specific headache patterns emerge—not for the constellation of symptoms described. The presence of systemic inflammatory markers makes primary CNS pathology highly unlikely. 2