The following cells seen in the lymph node are indicative of

Explanation

## Correct Answer: B. Measles Measles produces a characteristic histopathological finding in lymph nodes: **Warthin-Finkeldey cells** (multinucleated giant cells with eosinophilic cytoplasm and multiple nuclei arranged in a syncytium). These are pathognomonic for measles and appear in the germinal centers of lymph nodes during the prodromal phase, before the characteristic maculopapular rash appears. The presence of these cells in lymph node biopsies is diagnostic of measles infection. Additionally, measles causes **lymphoid hyperplasia** with follicular hyperplasia and increased mitotic activity. In the respiratory tract, measles also produces **Koplik spots** (small white spots with red halos on the buccal mucosa opposite molars), which are also pathognomonic. The virus replicates in respiratory epithelium and spreads systemically, causing immune activation in lymphoid tissues. Recognition of Warthin-Finkeldey cells in lymph node histology is the gold standard for identifying measles pathologically, making this the correct answer. ## Why the other options are wrong **A. Influenza** — Influenza causes acute respiratory inflammation with neutrophilic infiltration and epithelial necrosis in the lungs, but does NOT produce characteristic multinucleated giant cells in lymph nodes. Lymph node changes in influenza are non-specific (reactive hyperplasia only). The question specifically asks about cells seen in lymph nodes, which rules out influenza. **C. CMV/infection** — CMV infection produces **'owl's eye' cells** (intranuclear inclusions with surrounding halo) in epithelial cells and fibroblasts, NOT multinucleated giant cells in lymph nodes. While CMV can cause lymphadenopathy, the characteristic cytopathic effect differs from measles. CMV inclusions are intranuclear, whereas Warthin-Finkeldey cells are multinucleated syncytia without the classic inclusion appearance. **D. Infectious Mononucleosis** — Infectious mononucleosis (EBV) causes **atypical lymphocytosis** with activated T lymphocytes (Downey cells) in peripheral blood and marked lymph node hyperplasia, but does NOT produce Warthin-Finkeldey cells. The lymph node histology shows follicular hyperplasia and paracortical expansion with activated lymphocytes, not multinucleated giant cells characteristic of measles. ## High-Yield Facts - **Warthin-Finkeldey cells** are multinucleated giant cells pathognomonic for measles, found in lymph node germinal centers during prodromal phase. - **Koplik spots** (white spots with red halos on buccal mucosa) appear 2–3 days before measles rash and are diagnostic. - Measles causes **lymphoid hyperplasia** with follicular hyperplasia in lymph nodes, visible on histology. - **Owl's eye cells** (intranuclear inclusions) are characteristic of CMV, not measles. - **Downey cells** (atypical lymphocytes) appear in infectious mononucleosis blood smear, not in lymph node histology as multinucleated giants. ## Mnemonics **WARTHIN = Measles Lymph Node Cells** **W**arthin-Finkeldey cells = **W**orld's most famous measles finding in lymph nodes. Multinucleated syncytia in germinal centers = diagnostic. **Viral Inclusions Memory Hook** **Measles** → Warthin-Finkeldey (syncytia, no inclusions); **CMV** → Owl's eye (intranuclear); **EBV** → Downey cells (atypical lymphocytes, not giant cells). ## NBE Trap NBE may pair "lymph node findings" with "infectious mononucleosis" because both cause lymphadenopathy and are viral infections; students unfamiliar with Warthin-Finkeldey cells may incorrectly choose EBV. The trap is confusing lymph node hyperplasia (seen in IM) with pathognomonic multinucleated giant cells (seen in measles). ## Clinical Pearl In India, measles remains a significant cause of childhood morbidity despite vaccination efforts. Lymph node biopsy showing Warthin-Finkeldey cells during the prodromal phase (before rash appears) allows early diagnosis and isolation, preventing nosocomial spread in crowded hospital settings—critical in resource-limited settings where measles complications are common. _Reference: Robbins & Cotran Pathologic Basis of Disease, Ch. 8 (Infectious Diseases); Harrison's Principles of Internal Medicine, Ch. 219 (Measles)_