Immunostaining was done with appropriate positive and negative controls and revealed: LCA (CD45) shows diffuse membranous staining of the reactive lymphoid population. CD20 highlights reactive B cells within the follicles, while CD3 highlights the inter-follicular T-cell population. CD15 stains scattered inflammatory cells. Cytokeratin (AE1/AE3) highlights the surface and crypt squamous epithelium and is negative within the lymphoid tissue. CD30 and ALK01 are negative.
Immunostaining demonstrates a preserved reactive B- and T-cell architecture, absence of aberrant epithelial or lymphoid populations, and negativity for CD30 and ALK, thus excluding epithelial or lymphomatous malignant changes and favoring a marked reactive process.
Referred block for immunostaining of Rt. tonsillar lesion diagnosed as focal infiltration by atypical large round cells recommended for typing by marker study (pathology number 4497-2026 on 3 July 2026).
The case was submitted for review with new radiological data: CT scans demonstrate extensive multi-station lymphadenopathy involving the cervical, mediastinal, hilar, right paratracheal, and portocaval regions, with the largest hilar lymph node measuring 4.6 × 3.5 cm. Some cervical lymph nodes show central necrosis. Mild bilateral ground-glass opacities, scattered pulmonary micronodules, and minimal right pleural effusion are also present. The findings are suspicious for either granulomatous disease (e.g., tuberculosis or sarcoidosis) or a lymphoproliferative disorder.
Two referred paraffin blocks coded 4497-2026.
Immunostaining of Right tonsillectomy:
Comment
Given the extensive mediastinal, hilar, and portocaval lymphadenopathy on CT, a complete lymph node biopsy is strongly recommended. The reactive right tonsillar biopsy does not explain or represent the widespread thoracic and abdominal lymphadenopathy. An intact lymph node biopsy is essential to assess nodal architecture, exclude lymphoma, and differentiate sarcoidosis, tuberculosis, and other systemic inflammatory disorders.