The differential diagnosis to be considered for cervical/submandibular lymphadenopathy in a child post-renal transplant is as follows:
a)
Post-transplant lymphoproliferative disorder: usually associated with an Epstein–Barr virus infection. It may be insidious, resembling infectious mononucleosis, or it can present as an aggressive form of lymphoma.
b)
In an immunosuppressed child presenting with fever, pharyngitis, and cervical lymphadenopathy, the differential diagnosis may include streptococcal infection and infectious mononucleosis.
c)
Tuberculosis.
d)
Kikuchi–Fujimoto disease: rare benign and self-limiting disease with a worldwide distribution and higher prevalence in the Asian population, characterized by regional cervical lymphadenopathy accompanied by mild fever and night sweats.
e)
Viral lymphadenitis.
f)
Human immunodeficiency virus infection.
g)
Kaposi’s sarcoma.
2.
Histopathology demonstrated a lymph node that was completely replaced by a metastatic tumor. Fig. 1 shows metastatic Kaposi’s sarcoma (KS)—H&E (×200) stain displays bland spindle cell proliferation with slit-like spaces in between that contain red blood cells. Lymphoid cells are seen at one end. Fig. 2 shows immunohistochemistry (×200) where the spindle cells are strongly and diffusely positive for human herpesvirus-8 (HHV8), confirming KS. Ancillary studies (immunohistochemistry): CD34-positive, HHV8-positive, S100-positive in the dendritic cells. Smooth muscle actin/creatine kinase (CK) and AE1/AE3/CK5/6 were negative. Hence, the findings were consistent with metastatic KS.
Fig. 1
Hematoxylin and eosin stain (×200) shows bland spindle cell proliferation with slit-like spaces in between that contain red blood cells. Lymphoid cells are seen at one end
Fig. 2
Immunohistochemistry for human herpesvirus -8 (×200)
×
×
3.
Management of KS of the lymph node involves reduction of immunosuppression, which is the initial management strategy. Changing the immunosuppression from calcineurin inhibitors to an mTOR inhibitor such as sirolimus can be considered because of its dual action of inhibiting the progression of KS and as an anti-rejection medication.
