L21 Pathology Of Neoplastic Lymphoproliferative Disorders Part I (PDF)

BMS 201 (blood and lymphatic system module) pathology of Lymphomas part 1 Hodgkin Lymphoma (HL) Lymphomas Definition: Lymphomas are malignant neoplasms derived from cells native to lympho...

BMS 201 (blood and lymphatic system module) pathology of Lymphomas part 1 Hodgkin Lymphoma (HL) Lymphomas Definition: Lymphomas are malignant neoplasms derived from cells native to lymphoid tissues (lymphocytes and rarely histiocytes). According to the nature of the neoplastic cells (the presence or absence of “Reed Sternberg = RS” Giant cells); two broad categories are recognized: 1. Hodgkin’s lymphoma (HL): with the presence of RS Giant cells 2. Non-Hodgkin’s lymphomas (NHLs): with the absence of RS Giant cells The differences between Hodgkin and Non Hodgkin lymphomas Hodgkin lymphoma Hodgkin lymphoma Non Hodgkin lymphoma LNs involved Often localized to one single Often involve multiple axial group of lymph nodes peripheral lymph nodes spread Contiguous Non Contiguous Mesenteric nodes Rarely involved Commonly involved and Waldeyer ring Extranodal Rare Common presentation Page 1 of 7  Hodgkin’s lymphoma (HL) Definition: A type of lymphoma; the diagnosis of which rests upon the identification of Reed-Sternberg (RS) cell or their variants in a background of reactive inflammatory cells. Clinical characters: 1. Age: The disease has two peaks; 1st in young adults; 2nd peak over the age of 50. 2. Localized to single axial group of L.N (cervical, mediastinal, para-aortic L.N) then spread in a stepwise fashion to the contiguous nodes. 3. Mesentric nodes & Waldeyer ring are rarely involved. 4. Extra-nodal involvement is uncommon. Gross picture: 1. Enlarged 2. Firm 3. Discrete then Later become adherent due to capsular invasion. 4. Cut surface: homogenous grey. Microscopic picture: 1- General features: - Loss of normal lymph node architecture. - Scattered neoplastic cells: Reed- Sternberg’s cells (RS) or their variants. - Reactive inflammatory cells in the Background (mature lymphocytes, eosinophils, plasma cells, neutrophils, Histiocytes). 2- specific features for specific types. Page 2 of 7 Reed Sternberg cells (RS): Large giant cell with abundant eosinophilic cytoplasm, large multilobated nucleus, and prominent eosinophilic nucleoli. The classic RS cells have two mirror-image nuclei, each containing a large Eosinophilic nucleolus giving “owl-eye” appearance. Reed-Sternberg cells originate from a germinal center or post–germinal center B lymphocytes. The immunophenotype of the RS cell is positive expression of CD15 & CD30. Page 3 of 7 Various types of RS cells: 1- Reed-Sternberg cell, classic variant 2- Reed-Sternberg cell, mononuclear variant 3- Reed-Sternberg cell, lacunar 4- Reed-Sternberg cell, lympho-histiocytic variant (L&H) popcorn variant 5- Reed-Sternberg cell, pleomorphic 6- Reed-Sternberg cell, mummified variant variant Page 4 of 7  Various types of Hodgkin’s lymphoma: 1- Classic Hodgkin Lymphoma (95%) a) Nodular sclerosis H.L. b) Mixed cellularity H.L. c) Lymphocyte rich H.L. d) Lymphocyte depletion H.L 2- Nodular lymphocyte predominance H.L (5%) 1- Nodular sclerosis H.L. - The most common subtype of HL (65-70%) - Occur in adolescent and young age. - Loss of normal lymph node architecture. - lacunar RS cells. - Reactive inflammatory cells in the Background (mature lymphocytes, eosinophils, plasma cells, neutrophils, Histiocytes). - Dense collageneous bands (sclerosis) subdivide the lymphoid tissue into circumscribed nodules. - Excellent prognosis. 2- Mixed cellularity H.L. - Occurs in 20-25% of HL. - This is the most common type in old ages male. - Loss of normal lymph node architecture. - Excess classic & mononuclear RS cells - Excess reactive inflammatory cells in the background (eosinophils, plasma cells, and histiocytes). - Systemic symptoms such as night sweats and weight loss are common. - The prognosis is intermediate Page 5 of 7 3- Lymphocyte rich H.L. - Uncommon form - Can occur at any age. - Loss of normal lymph node architecture. - Mononuclear and classic RS cells - The reactive inflammatory background is rich in mature Lymphocytes. - Excellent prognosis 4- Lymphocyte Depletion H.L. - The least common pattern. - Loss of normal lymph node architecture. - Few number of lymphocytes. - Numerous pleomorphic RS cells. - The Reed-Sternberg cells are infected with EBV in over 90% of cases - Very poor prognosis 5- Nodular lymphocyte predominance H.L - Loss of normal lymph node architecture. - Classic RS cells are extremely difficult to find but instead there is lympho-histiocytic (L&H) popcorn variant that have multilobed, puffy nucleus. - The reactive inflammatory background is characterized by nodular or diffuse infiltrate of mature lymphocytes admixed with histiocytes. - Excellent prognosis Page 6 of 7 Idea for H.L. staging The clinical and pathological stage are of clinical importance (Ann Arbor classification) 4 stages are divided according to: 1. the extention; above or below the diaphragm 2. then they are further divided on the basis of the absence (A) or presence (B) of the systemic symptoms including significant fever, night sweats, and unexplained loss of more than 10% of body weight. Staging of Lymphomas Stage I: Involvement of a single lymph node or involvement of a single extra- nodal organ. Stage II: Involvement of two or more lymph node regions on the same side of the diaphragm. Stage III: Involvement of two or more lymph node regions on both sides of the diaphragm; which may include the spleen (IIIS) Stage IV: Involvement of multiple extra-nodal organs (Disseminated disease). Good Luck and Best Wishes… Dr. Mona Younis Youssef A member of pathology team Page 7 of 7