CASE PRESENTATION

Case Summary

Short history ( 1 mth) Generalised lymphadenopathy Left hypochondrial pain Dark coloured urine in this illness Recurrent haemoglobinuria Death of a sibling of an illness at same

age

Clinical Examination

Generalised lymphadenopathy Pallor, ?tinge of jaundice, afebrile, no

petechiae Moderate Hepatosplenomegaly Tender Liver CVS, RS & CNS = nil of note

Laboratory Results

PCV 21%, WBC 360,000/mm3,

Platelet ?40,000 PBF: mononuclear cells,target cells,

severe hypochromia BMA: Hypercellular,megaloblastic

erythropoesis, sheets of heterogenous mononuclear cells.

Leukaemic Phase of Lymphoma

Leukaemic phase is uncommon in LCL More of B-lineage than T-lineage Recognised in Burkitt’s and T-cell lymphoblastic

lymphoma Only common in adult T-cell leukaemia/

lymphoma (ATLL) Median survival is 7 months Leukaemic phase is however common in low

grade lymphoma

Clinical Features

B – Cell (16) T – Cell (8)

Age 43-48 (71) 11-81 (56)

Sex 10M, 6F 4M, 4F

Hepatomegaly 7 4

Splenomegaly 10 6

Lymphadenopathy

11 5

Skin Infiltration 0 4

Haematological Features

B Cell T Cell

Lymphocytes 109/L

2-624 (56) 0.9-130 (10)

Haemoglobin (g/dl)

5.9-14.1 (10.6) 4.8-9.9 (8.8)

Neutrophils 1.1-19 (6.9) 0.1-7 (1.1)

Platelet 40-300 (129) 12-140 (80)

Percentage of B Cell Cases With Blood and Marrow Involvement

Type BM involvemen

PB at presentatio

PB at any time

Lymphocyti 52 Nil Nil

SLVL >80 All All

Immunocyt 63 4-61 6

Follicular 35 14 27

Mantle cell 59 26 Not known

Monocytoid 38 Rare 3

Centroblast 16 2 3

Immunobla 28 Rare rare

Infectious Mononucleosis

>90% of people have the antibody worldwide.

Peak age is 15-19 years. Annual incidence is 345-671 per 100,000. The incidence is 30X higher in blacks. No gender difference. Chances of EBV infection becoming IM

increases with age.

Pathophysiology

Transmission is usually via oropharyngeal secretions.

Incubation period is 30-50 days. Virus initially infects oral epithelial cells then

spreads to B- lymphocytes. Spreads to RES triggering a massive but self

limiting immunologic response. Immunologic response may be responsible for

clinical features.

Neoplasms Associated With EBV

Burkitt’s Lymphoma. Nasopharyngeal carcinoma. Acute Lymhoblastic Lymphoma. Acute Monocytic Leukaemia. Histiocytic Lymphoma.

Causes Of Acute IM

Epstein Barr Virus. Cytomegalovirus. Human Herpesvirus 6. Human Immunodeficiency Virus. Toxoplasma Gondii. Cornebacterium Diphtheriae. Hepatitis A virus. Influenza A/B virus.

Clinical Features

Fever. Pharingitis. Generalised Lymphadenopathy. Splenomegaly. Jaundice. Maculopapular rash. Hepatomegaly.

Laboratory Test

Heterophile antibody test – monospot test. Sensitivity:63-84%. Specificity: 84-100%. Test positivity increases with time. False positve results rare. Test remains postive after one year.

Haematological Tests

Leukocytosis. Lymphocytosis (>50%). Atypical Lymphocytes (10%). Mild Thrombocytopaenia (50%). Haemolytic anaemia (3%).

Other Tests

2-3 fold rise in transaminases in 90%. Proteinuria. Microscopic Haematuria. Pyuria.

Complications

Upper airway obstruction. Splenic rupture. Chronic fatigue. CNS : Cranial nerve palsies, Gullain Barre

syndrome,encephalities. Peripheral neuropathies.

CONCLUSION

A variety of unusual reactive conditions may be seen in lymph nodes from the pediatric age group. Some of these, such as the autoimmune lymphoproliferative syndrome, reflect underlying abnormalities of the immune system and cellular control processes, while others are related to viral infections or are of unknown cause. Many of these conditions can mimic malignant neoplasms, so it is important that pathologists recognize these unusual reactive patterns.

Lymph node lesions in infectious mononucleosis (IM) show a marked histological diversity and may occasionally be confused with malignant lymphoma. We report on a rare case of IM showing geographic lymph node necrosis as well as angiocentric lymphoproliferative lesions, and containing numerous centroblasts, immunoblasts and Reed-Sternberg (RS)-like cells. The patient was a 40-year-old Japanese man with signs and symptoms of classical IM. This was later confirmed serologically, but the necrotic area comprised 50% of a cervical lymph node. The large lymphoid cells, including RS-like cells, were CD3-, CD5-, CD15-, CD20+, CD30+, CD45RO-, CD79a+, LMPI+, and EBNA2+.

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In situ hybridization study also disclosed that these cells were associated with Epstein-Barr virus (EBV). The patient was disease free during a follow-up of 15 years. Although the classical IM syndrome rarely shows a close resemblance to lymphomatoid granulomatosis of the lymph node or to EBV+ B- cell lymphoproliferative disorders associated with an immunodeficient state on histology, it is important for pathologists to be aware of this type of lesion in diagnostic practice.

Peritoneal effusion appears to be an unusual complication of infectious mononucleosis (IM). The cytological features of peritoneal effusion from a patient affected by IM are presented. The patient was a 21-year-old Japanese woman, with typical and physical findings of IM. Ascites disappeared with resolution of acute IM. The cytospin smears of the ascitic fluid were highly cellular, consisting exclusively of lymphoid cells.

Lymphoid cells were composed of large cells with broad basophilic cytoplasm, as well as of small to medium-sized cells having scant cytoplasm and irregularly shaped nuclei. The overall cytomorphological pictures posed serious difficulties in differentiating this condition from those of peripheral T-cell lymphomas manifesting ascites. The majority of atypical lymphocytes, including large cells, expressed CD3 and CD8. The present case indicates that IM should be added to the list of lesions considered for the differential diagnosis of non-Hodgkin's lymphoma of the peritoneal fluid, particularly regarding young adults.

References

Am J Clin Pathol. 2004 Dec;122 Suppl:S87-97

Pathol Res Pract. 2004;200(1):53-7 Pathol Res Pract. 2004;200(1):47-51.