Aspiration Cytopathology of Lymph Nodes and Lymphoproliferative Neoplasms
Case 4 -
Paul E. Wakely, Jr.
A 17 y/o young man presents with a 1.5 cm. right posterior cervical lymph node of unknown duration.
He complains of an upper respiratory infection, and a slight fever.
| hypercellular smears with a range of lymphocytes|
| an abnormally high percentage of immunoblasts, and a lesser number of centroblasts|
| immunoblasts: enlarged nuclei, usually one nucleolus, a moderate amount of cytoplasm which in the Diff-Quik stain has a deeply basophilic peripheral border|
| plasmacytoid lymphocytes and rare binucleated cells were also present; there were no FC fragments.|
Diagnosis: Infectious Mononucleosis
Table 26. Infectious Mononucleosis(IM), clinical features:
| a virally induced (Epstein-Barr virus) disorder spread from person-to-person contact that primarily affects adolescents and young adults; a wide age range|
| self-limited, 3-4 weeks|
| adolescents, young adults|
| typical clinical: fever, malaise, pharyngitis, lymphadenopathy (typically cervical, but axillary and inguinal also).|
| lymph nodes often tender to palpation, and movable|
| splenomegaly is common; splenic rupture secondary to trauma possible|
| laboratory findings: peripheral blood atypical lymphocytosis, positive monospot (heterophil) test|
EBV stimulates a polyclonal B-cell proliferation which in turn stimulates a killer T-cell response.
IM is thus a combined clinical-serologic diagnosis.
IM is one of several EBV induced diseases:
Table 27. EBV Positive T-Cell Disorders
| • Infectious Mononucleosis ||• Angioimmunoblastic T-Cell Lymphoma|
|• B cell In Peripheral T-Cell Lymphoma ||• Aggressive NK-Cell Lymphoma|
|• Extra-nodal NK/T-Cell Lymphoma ||• Enteropathy-type T-Cell Lymphoma|
|• Plasmablastic Lymphoma|| |
Role of FNA is to suggest or exclude this diagnosis in a patient who has either not
undergone serologic testing, or whose serology is negative thus attempting to avoid an excisional biopsy
when it may be unnecessary. Occasionally FNA is also used to exclude, or diagnose a malignant lymphoma
in a patient with IM-like clinical symptoms.
Aspiration smears are hypercellular with a polymorphous lymphoid population characterized
by an increased percentage of immunoblasts, centroblasts, plasmacytoid lymphocytes, and occasionally
increased plasma cells. Immunoblasts are large cells with fine nuclear chromatin, 1-3 prominent
nucleoli, and ample peripherally basophilic cytoplasm. Pleomorphic binucleated immunoblasts simulating
R-S cells are rare in aspirates. These cells are CD15 negative, but can be CD30 positive.
| Hodgkin's Lymphoma|
| large cell non-Hodgkin lymphoma|
| Kikuchi's disease|
Distinguishing aspirate of IM from RLH: recognize the increase of immunoblasts and
plasmacytoid lymphocytes coupled with the clinical picture. Unlike RLH, TBMs and FC fragments are only a
minor component of the IM smear, if present at all. Nonetheless, very early in the course of IM
lymphadenopathy may only demonstrate a florid RLH without the large population of transformed cells, and
IM can be indistinguishable from an early phase reactive lymph node. Other causes of immunoblast
proliferation: as anti-convulsant lymphadenopathy, Herpes simplex lymphadenitis, and drug
hypersensitivity - may be indistinguishable from IM.
Clinical and serologic data combined with the cytopathology is therefore necessary to make a specific
IBs and large lymphocytes of IM may be misinterpreted as large cell lymphoma. Distinct
from a lymphoma, however, a range of lymphoid cells still exists in IM even if immunoblasts predominate.
Immunophenotyping is helpful, and shows B-cell polyclonality with a suppressor/cytotoxic T-cell phenotype
in IM, unlike the monclonality of large cell lymphoma – most of which are B-cell type.
Kikuchi's lymphadenitis (Kikuchi-Fujimoto
| self-limited lymphadenopathy of unknown cause characterized by an abnormal proliferation of immunoblasts|
| uncommon in North America in contrast to its prevalence in Oriental women|
| lymphadenopathy (either single or multiple) principally affects cervical lymph nodes|
| patients may have fever, lymph node tenderness, atypical lymphocytosis of the peripheral blood similar to IM|
| Kikuchi's has been mistaken histologically for large cell lymphoma on occasion because the high percentage of immunoblasts.|
| increased IBs, monocytoid lymphocytes|
| a "dirty" background due to an abundance of cellular debris and karyorrhexis in this lymphadenopathy|
| absence of neutrophils|
| key feature: presence of phagocytic histiocytes with crescent-shaped, sometimes twisted nuclear contours that occasionally have a sharply angulated edge.|
These histiocytes are large, rounded, and had abundant cytoplasm that was distended with phagocytosed
granular and nuclear debris similar to the diathesis found in the smear background. Conventional TBMs
have oval/spherical nuclei without the crescentic configuration. It is important to note that
neutrophils are absent in Kikuchi's disease -unlike cat-scratch disease.
References for All Cases