Coexisting and clonally identical classic hodgkin lymphoma and nodular lymphocyte predominant hodgkin lymphoma

Abstract

We report a case of concurrent nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) and classic Hodgkin lymphoma (cHL), of nodular sclerosis subtype, in an otherwise healthy 24-year-old man with a strong family history of cHL. The patient was found to have a parotid mass, which was diagnosed as NLPHL, and a thymic mass diagnosed as cHL, of nodular sclerosis subtype concurrently. The lesion in the parotid showed features typical of NLPHL by morphology and immunophenotype. The LP cells were positive for PAX5, CD20, Oct2, weakly positive for CD30, and negative for CD15. The thymic lesion, diagnosed as cHL, of nodular sclerosis subtype, showed prominent bands of fibrosis and Hodgkin/Reed-Sternberg and lacunar cells positive for CD30 and CD15. These cells were variably positive for CD20 and negative for Oct2. PAX5 was weakly positive. Immunoglobulin gene rearrangement studies by polymerase chain reaction were carried out on microdissected Hodgkin/Reed-Sternberg and LP cells, which were shown to have identically sized peaks. NLPHL and cHL are 2 distinct diseases and are almost never seen concurrently. We present a case in which polymerase chain reaction analysis indicated that the tumor cells of these 2 distinct entities were clonally identical.

Figure 1

Nodular lymphocyte predominant Hodgkin lymphoma. A, Vaguely nodular architecture with scattered large atypical cells with multilobulated nuclei characteristic of LP cells (H&E). (B) Characteristic LP cells with multilobulated and “popcorn” nuclei (H&E). (C) Scattered LP cells strongly positive with Oct2 and (D) strongly positive with CD20.

Figure 2

Classical Hodgkin lymphoma, nodular sclerosis subtype. A, Effacement of the thymic architecture by broad bands of fibrosis (bottom left) and scattered large atypical cells (H&E). (B) These cells have irregular nuclear contours, vesicular chromatin, and prominent nucleoli, characteristic of HRS cells in a background of small lymphocytes and eosinophils (H&E). These cells were weakly positive for PAX5 (inset) (C, D) and positive for CD30 and CD15, respectively.

Figure 3

Nodular lymphocyte predominant Hodgkin lymphoma (A) in the parotid gland showing two intense peaks in the IGK@ locus of 236 and 273 bps, consistent with a clonal process. (B) Intense peaks of identical size are also seen in the classical Hodgkin lymphoma, nodular sclerosis subtype, in the thymus. (C) The microdissected background small B-lymphocytes within the NLPHL are negative for a clonal process by both IGH@ (not shown) and IGK@ PCR.