BAC Lunchtime May 2025 Slide Club Summary
Case 1: Allergic Bronchopulmonary Aspergillosis (ABPA) in HIV-Positive Patient
Presenter: Dr Tony Maddox (West Hertfordshire Teaching Hospitals NHS Trust)
Clinical Summary:
- Patient: 53-year-old male, HIV-positive, well-controlled on HAART
- Presentation: Fluffy chest X-ray abnormalities; bronchoalveolar lavage (BAL) performed
- Cytology Findings:
- Highly cellular BAL with abundant mucus and foamy macrophages
- Eosinophils prominent (23% of total cell count)
- Presence of Charcot-Leyden crystals
- A single fungal hyphal structure consistent with Aspergillus (septate, acute angle branching)
- Microbiology:
- Culture: Aspergillus fumigatus
- PCR: Negative for Pneumocystis jirovecii
- Serology:
- Serum IgE: Elevated (2779 IU/mL)
- Aspergillus-specific IgE: Significantly raised (47 IU/mL)
- Diagnosis: Allergic Bronchopulmonary Aspergillosis (ABPA)
- Lesson: Despite being HIV-positive, the patient did not have a typical opportunistic infection (e.g., Pneumocystis) and demonstrated an allergic response typical of atopic individuals, highlighting the importance of approaching every case with an open mind and a thorough evaluation of the morphological evidence.
Case 2: Confirmed Pneumocystis Pneumonia
Contrast Case by Dr Maddox to show the morphological appearances of a more “typical” case for this history:
- Patient: HIV-positive male, mid-30s
- BAL Findings:
- Foamy, sponge-like casts
- Grocott stain confirmed presence of Pneumocystis jirovecii organisms
Case 3: Parathyroid Adenoma Masquerading as Cancer
Presenter: Dr Suzannah Hazeldine (Royal Cornwall Hospitals NHS Trust)
Clinical Summary:
- Patient: 75-year-old female with known cancer above and below the diaphragm
- Presentation: Cystic mediastinal lymph node sampled via EBUS
- Cytology Findings:
- Tightly clustered cells with well-defined cytoplasm, anisonucleosis, stippled chromatin
- Dual cell populations resembling neuroendocrine differentiation
- Immunohistochemistry:
- Positive: synaptophysin diffusely positive, CK7 focal
- Negative: PAX8, P40, TTF-1
- Further Imaging: CT noted unusual mediastinal nodule extending to thyroid
- Additional Workup:
- Clinical context: Hypercalcemia
- SPECT scan confirmed a right parathyroid adenoma
- Final Diagnosis: Sampling of parathyroid epithelium; adenoma unrelated to patient’s known malignancy
- Lesson: Highlights the diagnostic value of integrating cytology, immuno, clinical context, and radiology.
Key Takeaways:
- Maintain broad differentials—even in immunocompromised patients.
- Cytological details can reveal unsuspected diagnoses like ABPA or parathyroid adenoma.
- Preserving traditional techniques (e.g., Grocott staining) complements molecular diagnostics and ensures rare or unexpected findings are not missed.