Lymphangioma-like Kaposi sarcoma.
BACKGROUND
Lymphangioma-like Kaposi's sarcoma (LLKS) is a rare morphologic expression of Kaposi's sarcoma (KS) that occurs in virtually all of the well-recognized clinical subtypes of the disease and has the potential to mimic other pathologic processes. In this study, we present the clinical and pathological features of four patients with LLKS.


METHODS
Four cases of LLKS were retrieved from the dermatopathology files of our institution. All four tumours were tested immunohistochemically with anti-human herpesvirus-8 (HHV-8) latent nuclear antigen-1 (LNA-1) and anti-CD34 antibodies.


RESULTS
Clinically, each patient presented with violaceous patches, papules or plaques; one patient presented with bullous lesions. All of the LLKS biopsy specimens revealed areas with characteristic light microscopic features of KS. Lymphangioma-like foci consisted of ectatic, irregularly shaped vascular spaces lined by mildly atypical endothelial cells. All tumour cells, including those associated with LLKS foci, showed a strong and diffuse reactivity for anti-HHV-8 LNA-1 and anti-CD34. KS progressed slowly in two patients with adequate follow-up.


CONCLUSIONS
As LLKS can mimic other disease processes, the correct diagnosis relies heavily on the recognition of salient clinical and histological features of conventional KS, including a strong immunohistochemical expression of HHV-8-associated LNA-1 in lesional cells.
Ramirez
James A
JA
Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA. j-ramirez@northwestern.edu
Laskin
William B
WB
Guitart
Joan
J
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018952:Antigens, CD34 / Q000032:analysis; D000956:Antigens, Viral / Q000032:analysis; D014408:Biomarkers, Tumor / Q000032:analysis; D017809:Fatal Outcome; D005260:Female; D019288:Herpesvirus 8, Human / Q000276:immunology; D006801:Humans; D008202:Lymphangioma / Q000737:chemistry / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009687:Nuclear Proteins / Q000032:analysis; D010750:Phosphoproteins / Q000032:analysis; D012514:Sarcoma, Kaposi / Q000737:chemistry / Q000473:pathology*; D012878:Skin Neoplasms / Q000737:chemistry / Q000473:pathology*
D018952:Antigens, CD34; D000956:Antigens, Viral; D014408:Biomarkers, Tumor; D009687:Nuclear Proteins; D010750:Phosphoproteins; C118485:latent nuclear antigen (LNA)