Anaplastic Large Cell Lymphoma Masquerading as Classical Hodgkin Lymphoma on Fine Needle Aspiration A Potential Diagnostic Pitfall ~ones, M.D.,* James A. Strauchen, M.D., and Frances Rosario-Quin Fadi Salem, M.D.
A 54-year-old male presented with inguinal lymphadenopathy and subjective fevers. On physical examination, a single 3-cm lymph node was palpated in the left inguinal canal. A superficial FNA of the lymph node was performed with a 27-gauge needle. Air-dried and alcohol-fixed smears were prepared for Diff-Quik and Papanicolaou stains, respectively, and a portion of the FNA sample was submitted for cell block preparation. The FNA material showed a heterogenous population of lymphocytes including scattered eosinophils and neutrophils (Figs. 1 and 2). Abundant large, binucleated neoplastic cells with amphophilic cytoplasm and prominent basophilic nucleoli were identified. These were thought to be most consistent with Reed–Sternberg (RS) cells of Hodgkin lymphoma. The corresponding cell block showed extensive crush artifact. Immunohistochemical stains (Ventana) were attempted and scattered large cells were positive for CD30 and CD15. Numerous PAX 5 positive cells were identified in the cell block specimen (Fig. 3). Focal staining for epithelial membrane antigen (EMA) was also observed. A diagnosis of “Highly suspicious for Hodgkin lymphoma” was rendered and the patient was enrolled in a clinical trial. Staging PET scan images showed diffuse abdominal, axillary, and inguinal lymphadenopathy. Subsequent excisional biopsy of the inguinal lymph
Department of Pathology, Mount Sinai School of Medicine and Medical Center, New York, New York *Correspondence to: Frances Rosario Qui~ nones, Annenberg Building, 15th Floor, 1468 Madison Avenue, New York, NY 10029, USA. E-mail: [email protected] Received 24 July 2014; Revised 11 February 2015; Accepted 30 March 2015 DOI: 10.1002/dc.23290 Published online 16 July 2015 in Wiley Online Library (wileyonlinelibrary.com).
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node revealed architectural effacement, with thick, sclerotic bands surrounding multiple lymphoid nodules. Sheets of large, multinucleated cells were identified with admixed inflammatory infiltrates (Fig. 4), and immunohistochemical stains of the excisional biopsy showed the large neoplastic cells to be positive for CD30 in a membranous and Golgi pattern, negative for CD15, and negative for PAX5 (Fig. 5). Multiple T-cell markers were evaluated, and the neoplastic cells retained CD4 and lost expression of CD3, CD5, and CD7. The above mentioned features supported the diagnosis of anaplastic large cell lymphoma. Immunostains for anaplastic lymphoma kinase (ALK) protein were negative, rendering a diagnosis of anaplastic large cell lymphoma, ALK negative. Anaplastic large cell lymphoma (ALCL) refers to a group of CD30-positive T-cell lymphomas characterized by the absence or presence of ALK protein expression. In the ALK-positive variant, four patterns have been described. The common pattern accounts for 60% of ALK-positive ALCL and consists of large cells with abundant eosinophilic cytoplasm and wreath-like nuclei, termed “hallmark cells.” The lymphohistiocytic pattern accounts for 10% of ALK-positive ALCL and consists of smaller hallmark cells admixed with reactive histiocytes. The small cell pattern accounts for 5–10% of ALKpositive ALCL and consists of small to medium cells with irregular, centrally located nuclei. The Hodgkin-like pattern accounts for 3% of ALK-positive ALCL and histologically mimics nodular sclerosis Hodgkin lymphoma with abundant tumor cells.1 ALK-negative ALCL shows a similar morphological spectrum to ALK-positive ALCL, although a “small cell variant” is not recognized in ALKnegative ALCL. C 2015 WILEY PERIODICALS, INC. V
Diagnostic Cytopathology DOI 10.1002/dc
FNA ANAPLASTIC LYMPHOMA
ALK-negative ALCL is a provisional entity in the WHO and refers to a neoplasm that is morphologically indistinguishable from ALK-positive ALCL, but lacks ALK protein expression. It generally presents in the fourth through
sixth decades of life and may involve both lymph nodes and extra nodal tissue.2 The tissue architecture is effaced by sheets of cohesive neoplastic hallmark cells, which characteristically stain positive for CD30 in a membranous and Golgi pattern.3,4 The presence of eosinophils and sclerosis is not uncommon, and when present, should
Fig. 1. Fine-needle aspiration of inguinal lymph node showing a large, binucleated cell with abundant basophilic cytoplasm and prominent nucleoli (diff quick stain, 1,0003).
Fig. 2. Multiple large, multinucleated tumor cells are seen in a background of neutrophils, plasma cells, and eosinophils (diff quick stain, 4003).
Discussion
Fig. 3. Cell block specimen (top left) showing extensive crush artifact and few large, binucleated cells. Large cells show CD30 staining (top right) in a membranous and Golgi pattern. Scattered large cells were positive for CD15 (bottom left). Numerous PAX 5 positive cells were identified (bottom right). Diagnostic Cytopathology, Vol. 43, No 11
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Diagnostic Cytopathology DOI 10.1002/dc
~ ROSARIO-QUINONES ET AL.
raise the concern of classical Hodgkin lymphoma (CHL). The clinical, morphologic, and immunophenotypic features of both lymphomas are highlighted in Table I.
Fig. 4. Inguinal lymph node, excisional biopsy, low power (403) view showing architectural effacement and a vaguely nodular proliferation with sclerotic bands surrounding lymphoid nodules, reminiscent of nodular sclerosis Hodgkin lymphoma. Inset: Inguinal lymph node, excisional biopsy, high power (2003) view showing a large, bi-nucleated cell with prominent nucleoli in the center of the field, consistent with the findings of the fine-needle aspiration specimen.
CHL is a B-cell lymphoma that accounts for 95% of all Hodgkin lymphomas, showing a peak at the first three decades of life, and a second peak in late life. CHL often involves cervical, mediastinal, axillary, and para-aortic lymph nodes. The lymph node architecture is effaced by variable numbers of RS cells admixed with a rich inflammatory background. The immunophenotype of the RS cells is that of post germinal center B-cells, with 95% of cases expressing PAX 5 in a weak nuclear pattern. RS cells are also positive for CD30 in nearly all cases, and for CD15 in up to 85% of cases. CD15 expression may be expressed by a minority of the neoplastic cells and restricted to the Golgi area. Although CD15 staining is absent in ALCL, similar CD30 staining pattern in both entities can lead to diagnostic confusion, especially so in cell block specimens with scanty diagnostic material. Positivity for the B-cell marker PAX 5 is a key feature in differentiating CHL from ALCL. PAX 5 is a nuclear protein mostly expressed in Blymphocytes and B-cell lymphomas. The main role of PAX 5 immunohistochemistry in the diagnosis of T-cell and NK-cell malignancies is in excluding B-cell lineage in neoplasms that may mimic T-cell dyscrasias either in morphology or immunophenotype. PAX 5 is therefore helpful in distinguishing CHL from ALCL. The
Fig. 5. Inguinal lymph node, excisional biopsy, immunohistochemical stains showed the tumor cells to be positive for CD30 (top left) in a membranous and Golgi pattern. CD15, usually positive in CHL (top right) and PAX 5, a B-cell marker (bottom left) were negative in the neoplastic cells. CD4 (bottom right) was positive both in the neoplastic cells and the background lymphocytes. The immunohistochemical findings ruled out CHL and favored a diagnosis of ALCL.
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Diagnostic Cytopathology DOI 10.1002/dc
FNA ANAPLASTIC LYMPHOMA Table I. Clinical and Histological Features of CHL and ALCL Diagnosis Clinical features Morphology Immunophenotype
Nodular sclerosis classical Hodgkin lymphoma
Anaplastic large cell lymphoma, ALK2
Peak incidence 15–34 years Cervical and mediastinal lymphadenopathy B symptoms Nodules surrounded by collagen bands Variable numbers of RS cells Numerous eosinophils, neutrophils, and histiocytes
Peak incidence (40–65 years) Peripheral or abdominal lymphadenopathy Advanced disease at presentation is common “Hallmark cells” with eccentric, horseshoe shaped nuclei Polymorphic background of neutrophils, lymphocytes, and histiocytes CD301, Granzyme/perforin1, CD451, patchy EMA1 CD152, PAX52, incomplete T cell phenotype
CD301, PAX 51, CD151, CD202, CD452, EMA2
EMA, epithelial membrane antigen.
neoplastic cells in both disorders are positive for CD30. Both conditions have considerable immunophenotypic overlap and ALCL may also have histologic features mimicking CHL, particularly the nodular sclerosis subtype. PAX 5 is, however, consistently negative in ALCL. The proportion of CHL cases positive for PAX 5 varies in the literature and has been reported to be as high as 100%. The intensity of PAX 5 staining often is weaker RS cells than in non-Hodgkin B-cell lymphomas and reactive B cells.5 ALK-negative ALCL is a T-cell neoplasm with a vast morphologic spectrum. Rapkiewicz et al. noted that the hallmark cell can be a helpful clue for the diagnosis of ALCL in FNA. It may, however, not be the predominant cell in a smear, raising the possibility for other diagnoses; most importantly CHL.6 Both neoplasms share many features, including RS-like cells, a polymorphic background of neutrophils, lymphocytes, and histiocytes, as well as CD30 expression. PAX 5 and CD15 are expected to be positive in CHL, yet negative in ALCL. ALK expression is not observed in CHL, and may be of use in cases of ALK-positive ALCL. In conclusion, in cases where ALK-negative ALCL is suspected, the importance of obtaining adequate material,
keeping a wide differential diagnosis, and utilizing ancillary techniques is paramount. Careful cytological evaluation of the neoplastic cells will provide a clue for further investigation, mainly procuring extra material via FNA biopsy for additional immunohistochemical studies.
References 1. Mason DY, Harris NL, Delsol G, et al. Anaplastic large cell lymphoma, ALK-negative. In: Swerdlow S, Campo E, Harris N, et al., editors. WHO classification of tumours of haematopoietic and lymphoid tissues. Lyon: International Agency for Research on Cancer; 2008. p 317–319. 2. Ferreri AJ, Govi S, Pileri SA, Savage KJ. Anaplastic large cell lymphoma, ALK-negative. Crit Rev Oncol Hematol 2013;85: 206–215. 3. Campo E, Swerdlow SH, Harris NL, et al. The 2008 WHO classification of lymphoid neoplasms and beyond: Evolving concepts and practical applications. Blood 2011;117:5019–5032. 4. Parilla Castellar ER, Jaffe ES, Said JW, et al. ALK-negative anaplastic large cell lymphoma is a genetically heterogeneous disease with widely disparate clinical outcomes. Blood 2014;124: 1473–1480. 5. Feldman AL, Dogan A. Diagnostic Uses of PAX5 Immunohistochemistry. Adv Anat Pathol 2007;14:323–334. 6. Rapkiewicz A, Wen H, Sen F, Das K. Cytomorphologic examination of anaplastic large cell lymphoma by fine-needle aspiration cytology. Cancer 2007;111:499–507.
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A 54-year-old male presented with inguinal lymphadenopathy and subjective fevers. On physical examination, a single 3-cm lymph node was palpated in the left inguinal canal. A superficial FNA of the lymph node was performed with a 27-gauge needle. Air-dried and alcohol-fixed smears were prepared for Diff-Quik and Papanicolaou stains, respectively, and a portion of the FNA sample was submitted for cell block preparation. The FNA material showed a heterogenous population of lymphocytes including scattered eosinophils and neutrophils (Figs. 1 and 2). Abundant large, binucleated neoplastic cells with amphophilic cytoplasm and prominent basophilic nucleoli were identified. These were thought to be most consistent with Reed–Sternberg (RS) cells of Hodgkin lymphoma. The corresponding cell block showed extensive crush artifact. Immunohistochemical stains (Ventana) were attempted and scattered large cells were positive for CD30 and CD15. Numerous PAX 5 positive cells were identified in the cell block specimen (Fig. 3). Focal staining for epithelial membrane antigen (EMA) was also observed. A diagnosis of “Highly suspicious for Hodgkin lymphoma” was rendered and the patient was enrolled in a clinical trial. Staging PET scan images showed diffuse abdominal, axillary, and inguinal lymphadenopathy. Subsequent excisional biopsy of the inguinal lymph
Department of Pathology, Mount Sinai School of Medicine and Medical Center, New York, New York *Correspondence to: Frances Rosario Qui~ nones, Annenberg Building, 15th Floor, 1468 Madison Avenue, New York, NY 10029, USA. E-mail: [email protected] Received 24 July 2014; Revised 11 February 2015; Accepted 30 March 2015 DOI: 10.1002/dc.23290 Published online 16 July 2015 in Wiley Online Library (wileyonlinelibrary.com).
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node revealed architectural effacement, with thick, sclerotic bands surrounding multiple lymphoid nodules. Sheets of large, multinucleated cells were identified with admixed inflammatory infiltrates (Fig. 4), and immunohistochemical stains of the excisional biopsy showed the large neoplastic cells to be positive for CD30 in a membranous and Golgi pattern, negative for CD15, and negative for PAX5 (Fig. 5). Multiple T-cell markers were evaluated, and the neoplastic cells retained CD4 and lost expression of CD3, CD5, and CD7. The above mentioned features supported the diagnosis of anaplastic large cell lymphoma. Immunostains for anaplastic lymphoma kinase (ALK) protein were negative, rendering a diagnosis of anaplastic large cell lymphoma, ALK negative. Anaplastic large cell lymphoma (ALCL) refers to a group of CD30-positive T-cell lymphomas characterized by the absence or presence of ALK protein expression. In the ALK-positive variant, four patterns have been described. The common pattern accounts for 60% of ALK-positive ALCL and consists of large cells with abundant eosinophilic cytoplasm and wreath-like nuclei, termed “hallmark cells.” The lymphohistiocytic pattern accounts for 10% of ALK-positive ALCL and consists of smaller hallmark cells admixed with reactive histiocytes. The small cell pattern accounts for 5–10% of ALKpositive ALCL and consists of small to medium cells with irregular, centrally located nuclei. The Hodgkin-like pattern accounts for 3% of ALK-positive ALCL and histologically mimics nodular sclerosis Hodgkin lymphoma with abundant tumor cells.1 ALK-negative ALCL shows a similar morphological spectrum to ALK-positive ALCL, although a “small cell variant” is not recognized in ALKnegative ALCL. C 2015 WILEY PERIODICALS, INC. V
Diagnostic Cytopathology DOI 10.1002/dc
FNA ANAPLASTIC LYMPHOMA
ALK-negative ALCL is a provisional entity in the WHO and refers to a neoplasm that is morphologically indistinguishable from ALK-positive ALCL, but lacks ALK protein expression. It generally presents in the fourth through
sixth decades of life and may involve both lymph nodes and extra nodal tissue.2 The tissue architecture is effaced by sheets of cohesive neoplastic hallmark cells, which characteristically stain positive for CD30 in a membranous and Golgi pattern.3,4 The presence of eosinophils and sclerosis is not uncommon, and when present, should
Fig. 1. Fine-needle aspiration of inguinal lymph node showing a large, binucleated cell with abundant basophilic cytoplasm and prominent nucleoli (diff quick stain, 1,0003).
Fig. 2. Multiple large, multinucleated tumor cells are seen in a background of neutrophils, plasma cells, and eosinophils (diff quick stain, 4003).
Discussion
Fig. 3. Cell block specimen (top left) showing extensive crush artifact and few large, binucleated cells. Large cells show CD30 staining (top right) in a membranous and Golgi pattern. Scattered large cells were positive for CD15 (bottom left). Numerous PAX 5 positive cells were identified (bottom right). Diagnostic Cytopathology, Vol. 43, No 11
917
Diagnostic Cytopathology DOI 10.1002/dc
~ ROSARIO-QUINONES ET AL.
raise the concern of classical Hodgkin lymphoma (CHL). The clinical, morphologic, and immunophenotypic features of both lymphomas are highlighted in Table I.
Fig. 4. Inguinal lymph node, excisional biopsy, low power (403) view showing architectural effacement and a vaguely nodular proliferation with sclerotic bands surrounding lymphoid nodules, reminiscent of nodular sclerosis Hodgkin lymphoma. Inset: Inguinal lymph node, excisional biopsy, high power (2003) view showing a large, bi-nucleated cell with prominent nucleoli in the center of the field, consistent with the findings of the fine-needle aspiration specimen.
CHL is a B-cell lymphoma that accounts for 95% of all Hodgkin lymphomas, showing a peak at the first three decades of life, and a second peak in late life. CHL often involves cervical, mediastinal, axillary, and para-aortic lymph nodes. The lymph node architecture is effaced by variable numbers of RS cells admixed with a rich inflammatory background. The immunophenotype of the RS cells is that of post germinal center B-cells, with 95% of cases expressing PAX 5 in a weak nuclear pattern. RS cells are also positive for CD30 in nearly all cases, and for CD15 in up to 85% of cases. CD15 expression may be expressed by a minority of the neoplastic cells and restricted to the Golgi area. Although CD15 staining is absent in ALCL, similar CD30 staining pattern in both entities can lead to diagnostic confusion, especially so in cell block specimens with scanty diagnostic material. Positivity for the B-cell marker PAX 5 is a key feature in differentiating CHL from ALCL. PAX 5 is a nuclear protein mostly expressed in Blymphocytes and B-cell lymphomas. The main role of PAX 5 immunohistochemistry in the diagnosis of T-cell and NK-cell malignancies is in excluding B-cell lineage in neoplasms that may mimic T-cell dyscrasias either in morphology or immunophenotype. PAX 5 is therefore helpful in distinguishing CHL from ALCL. The
Fig. 5. Inguinal lymph node, excisional biopsy, immunohistochemical stains showed the tumor cells to be positive for CD30 (top left) in a membranous and Golgi pattern. CD15, usually positive in CHL (top right) and PAX 5, a B-cell marker (bottom left) were negative in the neoplastic cells. CD4 (bottom right) was positive both in the neoplastic cells and the background lymphocytes. The immunohistochemical findings ruled out CHL and favored a diagnosis of ALCL.
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Diagnostic Cytopathology, Vol. 43, No 11
Diagnostic Cytopathology DOI 10.1002/dc
FNA ANAPLASTIC LYMPHOMA Table I. Clinical and Histological Features of CHL and ALCL Diagnosis Clinical features Morphology Immunophenotype
Nodular sclerosis classical Hodgkin lymphoma
Anaplastic large cell lymphoma, ALK2
Peak incidence 15–34 years Cervical and mediastinal lymphadenopathy B symptoms Nodules surrounded by collagen bands Variable numbers of RS cells Numerous eosinophils, neutrophils, and histiocytes
Peak incidence (40–65 years) Peripheral or abdominal lymphadenopathy Advanced disease at presentation is common “Hallmark cells” with eccentric, horseshoe shaped nuclei Polymorphic background of neutrophils, lymphocytes, and histiocytes CD301, Granzyme/perforin1, CD451, patchy EMA1 CD152, PAX52, incomplete T cell phenotype
CD301, PAX 51, CD151, CD202, CD452, EMA2
EMA, epithelial membrane antigen.
neoplastic cells in both disorders are positive for CD30. Both conditions have considerable immunophenotypic overlap and ALCL may also have histologic features mimicking CHL, particularly the nodular sclerosis subtype. PAX 5 is, however, consistently negative in ALCL. The proportion of CHL cases positive for PAX 5 varies in the literature and has been reported to be as high as 100%. The intensity of PAX 5 staining often is weaker RS cells than in non-Hodgkin B-cell lymphomas and reactive B cells.5 ALK-negative ALCL is a T-cell neoplasm with a vast morphologic spectrum. Rapkiewicz et al. noted that the hallmark cell can be a helpful clue for the diagnosis of ALCL in FNA. It may, however, not be the predominant cell in a smear, raising the possibility for other diagnoses; most importantly CHL.6 Both neoplasms share many features, including RS-like cells, a polymorphic background of neutrophils, lymphocytes, and histiocytes, as well as CD30 expression. PAX 5 and CD15 are expected to be positive in CHL, yet negative in ALCL. ALK expression is not observed in CHL, and may be of use in cases of ALK-positive ALCL. In conclusion, in cases where ALK-negative ALCL is suspected, the importance of obtaining adequate material,
keeping a wide differential diagnosis, and utilizing ancillary techniques is paramount. Careful cytological evaluation of the neoplastic cells will provide a clue for further investigation, mainly procuring extra material via FNA biopsy for additional immunohistochemical studies.
References 1. Mason DY, Harris NL, Delsol G, et al. Anaplastic large cell lymphoma, ALK-negative. In: Swerdlow S, Campo E, Harris N, et al., editors. WHO classification of tumours of haematopoietic and lymphoid tissues. Lyon: International Agency for Research on Cancer; 2008. p 317–319. 2. Ferreri AJ, Govi S, Pileri SA, Savage KJ. Anaplastic large cell lymphoma, ALK-negative. Crit Rev Oncol Hematol 2013;85: 206–215. 3. Campo E, Swerdlow SH, Harris NL, et al. The 2008 WHO classification of lymphoid neoplasms and beyond: Evolving concepts and practical applications. Blood 2011;117:5019–5032. 4. Parilla Castellar ER, Jaffe ES, Said JW, et al. ALK-negative anaplastic large cell lymphoma is a genetically heterogeneous disease with widely disparate clinical outcomes. Blood 2014;124: 1473–1480. 5. Feldman AL, Dogan A. Diagnostic Uses of PAX5 Immunohistochemistry. Adv Anat Pathol 2007;14:323–334. 6. Rapkiewicz A, Wen H, Sen F, Das K. Cytomorphologic examination of anaplastic large cell lymphoma by fine-needle aspiration cytology. Cancer 2007;111:499–507.
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