Subcutaneous 'lipoma-like' B-cell lymphoma associated with HCV infection: a new presentation of primary extranodal marginal zone B-cell lymphoma of MALT.
BACKGROUND
Hepatitis C virus (HCV) infection has been linked to lymphoproliferative disorders. Marginal zone B-cell lymphoma (MZL) represents one of the most frequent lymphoma subtypes associated with HCV infection. We describe an unusual subset of HCV-associated MZL characterized by subcutaneous presentation.


METHODS
A series of 12 HCV-positive patients presenting with subcutaneous nodules that revealed lymphoma infiltration at biopsy. Molecular analysis of immunoglobulin heavy chain (IGH) gene rearrangement and FISH investigations for t(11;18)(q21;q21) and t(14;18)(q32;q21) were carried out in nine patients.


RESULTS
The 12 patients (median age 69.5 years), all with positive HCV serology, presented with single or multiple subcutaneous nodules resembling lipomas. Histologically the lesions showed lymphoid infiltrates, consistent with extranodal MZL of mucosa-associated lymphoid tissue (MALT). Functional IGH gene rearrangements were identified in nine tested patients, with somatic mutations in 82%, indicating a histogenesis from germinal center-experienced B cells. The t(11;18) was found in two of nine cases. Staging did not show any other lymphoma localization. In two patients, a response was achieved with antiviral treatment. Extracutaneous spread to MALT sites occurred in a case.


CONCLUSIONS
Our observations expand the spectrum of HCV-associated lymphomas to include a subset of extranodal MZL characterized by a novel primary 'lipoma-like' subcutaneous presentation and indolent clinical course.
Pathology Section, Department of Human Pathology. Electronic address: immunopat@smatteo.pv.it.
M
M
Paulli
Division of Hematology, Fondazione IRCCS Policlinico San Matteo, University of Pavia, Pavia.
L
L
Arcaini
Pathology Section, Department of Human Pathology.
M
M
Lucioni
Pathology Section, Department of Human Pathology.
E
E
Boveri
Division of Hematology, Department of Medical Sciences and IRCAD, Amedeo Avogadro University of Eastern Piedmont, Novara.
D
D
Capello
Division of Hematology, Fondazione IRCCS Policlinico San Matteo, University of Pavia, Pavia.
F
F
Passamonti
Division of Hematology, Fondazione IRCCS Policlinico San Matteo, University of Pavia, Pavia.
M
M
Merli
Division of Hematology, Fondazione IRCCS Policlinico San Matteo, University of Pavia, Pavia.
S
S
Rattotti
Division of Hematology, Department of Medical Sciences and IRCAD, Amedeo Avogadro University of Eastern Piedmont, Novara.
D
D
Rossi
Pathology Section, Department of Human Pathology.
R
R
Riboni
Department of Dermatology, University of Milano-Bicocca, Milano.
E
E
Berti
Pathology Section, Department of Human Pathology.
U
U
Magrini
Division of Tropical and Infectious Diseases, Fondazione IRCCS Policlinico San Matteo, University of Pavia, Pavia, Italy.
R
R
Bruno
Division of Hematology, Department of Medical Sciences and IRCAD, Amedeo Avogadro University of Eastern Piedmont, Novara.
G
G
Gaidano
Division of Hematology, Fondazione IRCCS Policlinico San Matteo, University of Pavia, Pavia.
M
M
Lazzarino
D000368:Aged; D002880:Chromosomes, Human, Pair 11; D002887:Chromosomes, Human, Pair 18; D003937:Diagnosis, Differential; D005260:Female; D015326:Gene Rearrangement, B-Lymphocyte, Heavy Chain / Q000235:genetics; D016174:Hepacivirus / Q000502:physiology; D006526:Hepatitis C / Q000150:complications / Q000175:diagnosis* / Q000235:genetics; D006801:Humans; D008067:Lipoma / Q000175:diagnosis* / Q000209:etiology / Q000235:genetics / Q000473:pathology; D016393:Lymphoma, B-Cell / Q000175:diagnosis* / Q000209:etiology / Q000235:genetics / Q000473:pathology; D018442:Lymphoma, B-Cell, Marginal Zone / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009372:Neoplasms, Connective Tissue / Q000175:diagnosis / Q000209:etiology / Q000235:genetics / Q000473:pathology; D012189:Retrospective Studies; D040521:Subcutaneous Tissue / Q000473:pathology*; D014178:Translocation, Genetic