- Email: [email protected]
Cutaneous B-cell lymphoma with histologic features of mycosis fungoides
CASE
REPORTS
Cutaneous B-cell lymphoma with histologic features of mycosis fungoides Sarah Chiang, MD,a David J. DiCaudo, MD,a,b Riccardo Valdez, MD,c and David L. Swanson, MDa Scottsdale, Arizona Histologic examination of skin biopsy specimens from a 57-year-old man with a pruritic rash on his chest, abdomen, and thighs revealed a dense atypical dermal lymphoid infiltrate bordering the dermoepidermal junction and scattered intraepithelial lymphocytes. Histopathologic and clinical features were suggestive of mycosis fungoides. Immunophenotyping studies, however, identified CD201 B lymphocytes with aberrant expression of CD43. Clonal immunoglobulin gene rearrangement was demonstrated, and no clonal T-cell gene rearrangement was identified. Morphologic and immunophenotypic features were most consistent with extranodal marginal zone B-cell lymphoma. Systemic evaluation identified involvement of the bone marrow and possibly the peripheral blood, spleen, and splenic lymph nodes. Cutaneous manifestations were treated with narrowband ultraviolet B phototherapy for 3 months, resulting in complete resolution of the pruritus and rash. Primary and secondary cutaneous B-cell lymphomas seldom mimic mycosis fungoides histologically. Immunophenotyping studies were critical in correctly classifying this rare example of an epidermotropic B-cell lymphoma. ( J Am Acad Dermatol 2010;62:320-3.) Key words: lymphoid tissue; phototherapy; pruritus.
CASE REPORT A 57-year-old man presented to the dermatology clinic in our tertiary care academic medical center with a 5-year history of an intermittently pruritic rash on the chest, abdomen, and thighs. The rash appeared to improve with topical 1% hydrocortisone, moisturizing lotions, and exposure to sunlight. The patient had no history of exposure to contactants. He denied having had any fevers, chills, night sweats, loss of appetite, weight loss, fatigue, nausea, or vomiting. His medical history was clinically significant for hyperlipidemia and gastroesophageal reflux disease treated with atorvastatin and rabeprazole. The patient had no family history of cancer or skin disorders. Physical examination revealed multiple erythematous papules on the chest (Fig 1), extending onto the abdomen and both thighs. Three skin biopsies were obtained from the right aspect of chest, right side aspect of chest, and left Department of Dermatology,a the Division of Anatomic Pathology,b and the Department of Laboratory Medicine and Pathology,c Mayo clinic. Funding sources: None. Conflicts of interest: None declared. Reprint requests: David L. Swanson, MD, Department of Dermatology, Mayo Clinic Hospital, 5777 East Mayo Blvd, Phoenix, AZ 85054. E-mail: [email protected]. Published online October 8, 2009. 0190-9622/$36.00 ª 2009 by the American Academy of Dermatology, Inc. doi:10.1016/j.jaad.2009.02.032
320
thigh. Microscopic evaluation of all 3 specimens demonstrated a dense bandlike infiltrate of small monomorphic lymphocytes admixed with scattered larger cells in the papillary dermis and superficial reticular dermis (Figs 2 and 3). The inlfiltrate abutted the dermoepidermal junction and was associated with vacuolization of keratinocytes near the basal cell layer. Rare small lymphocytes extended into the mid epidermis. Immunohistochemiclal analysis of paraffin sections from two of the biopsy specimens (right side of chest and left thigh) revealed identical immunophenotypic features. The atypical dermal lymphocytes expressed positive immunohistochemical staining for CD20 and bcl-2, but were negative for CD5, bcl-6, CD10, CD23, and CD43 (Fig 4). Scattered plasma cells within the infiltrate showed a polytypic staining pattern for k and l immunoglobulin light chains. A moderate number of CD31 T lymphocytes were scattered throughout the infiltrate (Fig 5). Some intraepithelial lymphocytes expressed CD3, but most expressed CD20. Polymerase chain reaction analysis of frozen tissue from the right chest specimen demonstrated a clonal immunoglobulin gene rearrangement. No T-cell receptor gene rearrangement was detected by polymerase chain reaction or Southern blot analysis. The histologic, immunophenotypic, and molecular findings were diagnostic of a low-grade cutaneous B-cell lymphoma with epidermotropism. As part of a staging evaluation, a peripheral blood sample was sent for a complete blood cell count,
J AM ACAD DERMATOL
Case reports 321
VOLUME 62, NUMBER 2
Fig 1. Multiple erythematous papules were present on the chest.
Fig 4. CD201 atypical lymphocytes with epidermotropism. (Original magnification: 3600.)
Fig 2. Skin biopsy specimen from left thigh with dense bandlike lymphocytic infiltrate in papillary dermis. (Hematoxylin-eosin stain; original magnification: 3100.)
Fig 5. CD31 lymphocytes admixed with atypical B-cell infiltrate. (Original magnification: 3600.)
Fig 3. Atypical lymphocytes fill papillary dermis and extend into epidermis. (Hematoxylin-eosin stain; original magnification: 3600.)
peripheral smear, and flow cytometry. Findings included a white blood cell count of 5.2 K/L (reference range [RR], 4.2-10.2) with a normal differential; hemoglobin of 13.6 (RR, 13.2-17.5); hematocrit of 38.8% (RR, 38.7-48.3); and a platelet count of 183 K/L (RR, 151-355). Rare atypical lymphoid cells were identified on peripheral smear; however, flow cytometry did not identify a clonal B lymphocyte population. Computed tomograms of the chest,
abdomen, and pelvis revealed an enlarged spleen and low-grade adenopathy in the splenic hilum, mesentery, and retroperitoneum. A bone-marrow biopsy was conducted for histologic examination and immunophenotyping studies. The bone-marrow core biopsy specimen revealed a prominent sinusoidal infiltrate of atypical CD201 B cells. Flow cytometric analysis of the bone-marrow aspirate confirmed a monoclonal B-lymphocyte population expressing CD19, CD20, CD22, CD45, FMC-7, and l immunoglobulin light chain. This population was negative for CD5, CD10, CD11c, CD23, and CD38. Histologic and immunophenotypic findings in the skin and bone marrow were diagnostic of an extranodal marginal zone B-cell lymphoma with widespread cutaneous disease. The patient was evaluated by specialists both in dermatology and hematology and by specialists in oncology, with dermatology follow-up. Aside from pruritus, the patient was asymptomatic for lymphoma, and systemic chemotherapy was deferred in the absence of systemic symptoms. For the cutaneous disease, the patient received 21 treatment sessions over 3 months of narrowband ultraviolet (UV) B phototherapy, ranging from 175 to 785 mJ/cm2, which produced complete resolution of
322 Case reports
J AM ACAD DERMATOL FEBRUARY 2010
the pruritus and a clearing of lesions. The patient continues to be monitored quarterly for recurrence of symptoms.
DISCUSSION The classic histopathologic appearance of mycosis fungoides is characterized by a bandlike lymphoid infiltrate in the dermis, epidermotropism, and intraepidermal collections of atypical lymphocytes.1 Cutaneous B-cell lymphomas typically consist of nodular to diffuse lymphoid infiltrates with relative sparing of the epidermis.1 However, as observed in our patient, both primary and secondary cutaneous B-cell lymphomas can mimic mycosis fungoides histologically, albeit rarely. Only a few such cases have been reported in the English-language medical literature. Glusac et al2 conducted a randomized review with masked assessment of hematoxylin-eosin slides from 77 patients with primary and secondary cutaneous Bcell lymphomas and 20 patients with nonmycosis fungoides and cutaneous T-cell lymphomas. Patients were categorized as having B-cell or T-cell lymphomas on the basis of morphologic structure alone. Of the 77 patients with B-cell lymphomas, 4 were incorrectly categorized as having T-cell lymphomas because of histologic features of atypical lymphoid infiltrate limited to the papillary dermis, epidermotropism, interstitial involvement, and lack of a grenz zone. All 4 cases demonstrated atypical lymphoid infiltrates in the dermis and intraepithelial lymphocytes. Subsequent analysis of immunohistochemical staining confirmed the presence of dermal lymphocytes that were predominantly monoclonal B lymphocytes with variable scattered T cells. In one patient, T lymphocytes alone infiltrated the epidermis. The other patients had mixed B lymphocytes and T lymphocytes in the epidermis, with one patient having epidermotropic lymphocytes that were mainly B cells. Three of these 4 patients were identified as having large-cell lymphomas, whereas one patient had a mixed-cell lymphoma. Chui et al3 described a patient who presented with a pruritic rash over the trunk and proximal arms and legs. A skin biopsy specimen showed a dense bandlike infiltrate of small round lymphocytes with abundant clear cytoplasm, prominent epidermotropism, and absent spongiosis. The diagnosis was presumed to be mycosis fungoides. Immunophenotypic studies, however, revealed a B-cell phenotype for most of the dermal and intraepithelial lymphocytes that expressed CD20 but were negative for CD10 and CD23. Scattered nodules of small CD201 lymphocytes were present in a bone-marrow biopsy specimen. Both skin and bone-marrow biopsy findings
were consistent with those for extranodal marginal zone lymphoma, and the patient was treated systemically with cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy. Metzman et al4 described one patient with B-cell chronic lymphocytic leukemia in whom erythematous, scaly, and mildly atrophic plaques developed on the thighs, back, and axillae that were characteristic of the patch and plaque stages of mycosis fungoides. A biopsy specimen of skin from the thigh demonstrated a bandlike infiltrate of small to medium lymphocytes in the papillary dermis and focal epidermotropism. Immunophenotypic studies showed that half of the dermal lymphocytes expressed CD2 and CD45. Clusters of lymphocytes expressed CD20 but were negative for CD2 and CD45. The CD4 to CD8 ratio was 3 to 1. Polymerase chain reaction revealed an immunoglobulin heavychain gene rearrangement and a germ-line T-cell receptor configuration. These findings corresponded to cutaneous chronic lymphocytic leukemia with a reactive T-cell process that mimicked mycosis fungoides. Landa et al5 reported on one patient with dermatomyositis and primary cutaneous B-cell lymphoma who presented with noduloulcerative disease of the lower extremities. Histologic findings showed a diffuse infiltrate of small and medium lymphocytes in the dermis that extended into the subcutaneous fat. Microscopic findings of epidermotropism and angioinvasion were suggestive of a T-cell neoplasm. Immunophenotyping studies showed that the lymphoid infiltrate in the superficial dermis and at the dermal-epidermal junction was composed primarily of T cells. However, atypical lymphocytes in the reticular dermis revealed a B-cell phenotype. Gene rearrangement studies confirmed a clonal B-cell population. Our report demonstrates that cutaneous B-cell lymphomas can show epidermotropic lymphoid infiltrates, which are typically more characteristic of cutaneous T-cell lymphomas. Our findings are consistent with those in other reports of rare B-cell lymphomas that noted a T-cell pattern mimicking mycosis fungoides. Although architectural features are often used to distinguish among different types of cutaneous lymphomas, they can sometimes cause confusion and may be misleading without the support of additional immunophenotyping studies. Epidermotropism is also found in other cutaneous diseases, including reactive inflammation and Langerhans cell histiocytosis.6 Thus, it is important to use caution when interpreting architectural features in lymphoproliferative malignancies involving the skin and to consider verifying such findings with immunohistochemical studies.
J AM ACAD DERMATOL
Case reports 323
VOLUME 62, NUMBER 2
To our knowledge, this case also represents the first published report of epidermotropic cutaneous B-cell lymphoma in which the patient had a complete clinical response to narrowband UVB phototherapy after 3 months of treatment. Narrowband UVB phototherapy recently became a first-line treatment for early-stage mycosis fungoides and has been used for psoriasis, atopic dermatitis, vitiligo, lichen planus, and other inflammatory skin disorders.7-9 Its mechanism of action may be related to the inhibition of antigen presentation9 and to the direct cytotoxicity to T lymphocytes,10 as noted in some studies on narrowband UVB phototherapy in T-lymphocytee mediated dermatoses. Our findings in this case suggest that narrowband UVB phototherapy may also have a suppressive effect on B lymphocytes. Narrowband UVB phototherapy appears to be an effective, well-tolerated treatment for the early cutaneous manifestations of epidermotropic cutaneous B-cell lymphoma.
REFERENCES 1. Willemze R, Jaffe ES, Burg G, Cerroni L, Berti E, Swerdlow SH, et al. WHO-EORTC classification for cutaneous lymphomas. Blood 2005;105:3768-85.
2. Glusac EJ, Kindel SE, Soslow RA, Smoller BR. Evaluation of classic architectural criteria in non-mycosis fungoides cutaneous lymphomas. Am J Dermatopathol 1997;19:557-61. 3. Chui CT, Hoppe RT, Kohler S, Kim YH. Epidermotropic cutaneous B-cell lymphoma mimicking mycosis fungoides. J Am Acad Dermatol 1999;41:271-4. 4. Metzman MS, Stevens SR, Griffiths CE, Ross CW, Barnett JM, Cooper KD. A clinical and histologic mycosis fungoides simulant occurring as a T-cell infiltrate coexisting with B-cell leukemia cutis. J Am Acad Dermatol 1995;33:341-5. 5. Landa NG, Zelickson BD, Kurtin PJ, Winkelmann RK. Primary Bcell lymphoma with histologic features of a T-cell neoplasm. J Am Acad Dermatol 1992;26:288-92. 6. Slater DN. Cutaneous lymphoproliferative disorders: an assessment of recent investigative techniques. Br J Dermatol 1991;124:309-23. 7. Brazzelli V, Antoninetti M, Palazzini S, Prestinari F, Borroni G. Narrow-band ultraviolet therapy in early-stage mycosis fungoides: study on 20 patients. Photodermatol Photoimmunol Photomed 2007;23:229-33. 8. Gambichler T, Breuckmann F, Boms S, Altmeyer P, Kreuter A. Narrowband UVB phototherapy in skin conditions beyond psoriasis. J Am Acad Dermatol 2005;52:660-70. 9. Pavlotsky F, Nathansohn N, Kriger G, Shapiro D, Trau H. Ultraviolet-B treatment for cutaneous lichen planus: our experience with 50 patients. Photodermatol Photoimmunol Photomed 2008;24:83-6. 10. Ozawa M, Ferenczi K, Kikuchi T, Cardinale I, Austin LM, Coven TR, et al. 312-Nanometer ultraviolet B light (narrow-band UVB) induces apoptosis of T cells within psoriatic lesions. J Exp Med 1999;189:711-8.
REPORTS
Cutaneous B-cell lymphoma with histologic features of mycosis fungoides Sarah Chiang, MD,a David J. DiCaudo, MD,a,b Riccardo Valdez, MD,c and David L. Swanson, MDa Scottsdale, Arizona Histologic examination of skin biopsy specimens from a 57-year-old man with a pruritic rash on his chest, abdomen, and thighs revealed a dense atypical dermal lymphoid infiltrate bordering the dermoepidermal junction and scattered intraepithelial lymphocytes. Histopathologic and clinical features were suggestive of mycosis fungoides. Immunophenotyping studies, however, identified CD201 B lymphocytes with aberrant expression of CD43. Clonal immunoglobulin gene rearrangement was demonstrated, and no clonal T-cell gene rearrangement was identified. Morphologic and immunophenotypic features were most consistent with extranodal marginal zone B-cell lymphoma. Systemic evaluation identified involvement of the bone marrow and possibly the peripheral blood, spleen, and splenic lymph nodes. Cutaneous manifestations were treated with narrowband ultraviolet B phototherapy for 3 months, resulting in complete resolution of the pruritus and rash. Primary and secondary cutaneous B-cell lymphomas seldom mimic mycosis fungoides histologically. Immunophenotyping studies were critical in correctly classifying this rare example of an epidermotropic B-cell lymphoma. ( J Am Acad Dermatol 2010;62:320-3.) Key words: lymphoid tissue; phototherapy; pruritus.
CASE REPORT A 57-year-old man presented to the dermatology clinic in our tertiary care academic medical center with a 5-year history of an intermittently pruritic rash on the chest, abdomen, and thighs. The rash appeared to improve with topical 1% hydrocortisone, moisturizing lotions, and exposure to sunlight. The patient had no history of exposure to contactants. He denied having had any fevers, chills, night sweats, loss of appetite, weight loss, fatigue, nausea, or vomiting. His medical history was clinically significant for hyperlipidemia and gastroesophageal reflux disease treated with atorvastatin and rabeprazole. The patient had no family history of cancer or skin disorders. Physical examination revealed multiple erythematous papules on the chest (Fig 1), extending onto the abdomen and both thighs. Three skin biopsies were obtained from the right aspect of chest, right side aspect of chest, and left Department of Dermatology,a the Division of Anatomic Pathology,b and the Department of Laboratory Medicine and Pathology,c Mayo clinic. Funding sources: None. Conflicts of interest: None declared. Reprint requests: David L. Swanson, MD, Department of Dermatology, Mayo Clinic Hospital, 5777 East Mayo Blvd, Phoenix, AZ 85054. E-mail: [email protected]. Published online October 8, 2009. 0190-9622/$36.00 ª 2009 by the American Academy of Dermatology, Inc. doi:10.1016/j.jaad.2009.02.032
320
thigh. Microscopic evaluation of all 3 specimens demonstrated a dense bandlike infiltrate of small monomorphic lymphocytes admixed with scattered larger cells in the papillary dermis and superficial reticular dermis (Figs 2 and 3). The inlfiltrate abutted the dermoepidermal junction and was associated with vacuolization of keratinocytes near the basal cell layer. Rare small lymphocytes extended into the mid epidermis. Immunohistochemiclal analysis of paraffin sections from two of the biopsy specimens (right side of chest and left thigh) revealed identical immunophenotypic features. The atypical dermal lymphocytes expressed positive immunohistochemical staining for CD20 and bcl-2, but were negative for CD5, bcl-6, CD10, CD23, and CD43 (Fig 4). Scattered plasma cells within the infiltrate showed a polytypic staining pattern for k and l immunoglobulin light chains. A moderate number of CD31 T lymphocytes were scattered throughout the infiltrate (Fig 5). Some intraepithelial lymphocytes expressed CD3, but most expressed CD20. Polymerase chain reaction analysis of frozen tissue from the right chest specimen demonstrated a clonal immunoglobulin gene rearrangement. No T-cell receptor gene rearrangement was detected by polymerase chain reaction or Southern blot analysis. The histologic, immunophenotypic, and molecular findings were diagnostic of a low-grade cutaneous B-cell lymphoma with epidermotropism. As part of a staging evaluation, a peripheral blood sample was sent for a complete blood cell count,
J AM ACAD DERMATOL
Case reports 321
VOLUME 62, NUMBER 2
Fig 1. Multiple erythematous papules were present on the chest.
Fig 4. CD201 atypical lymphocytes with epidermotropism. (Original magnification: 3600.)
Fig 2. Skin biopsy specimen from left thigh with dense bandlike lymphocytic infiltrate in papillary dermis. (Hematoxylin-eosin stain; original magnification: 3100.)
Fig 5. CD31 lymphocytes admixed with atypical B-cell infiltrate. (Original magnification: 3600.)
Fig 3. Atypical lymphocytes fill papillary dermis and extend into epidermis. (Hematoxylin-eosin stain; original magnification: 3600.)
peripheral smear, and flow cytometry. Findings included a white blood cell count of 5.2 K/L (reference range [RR], 4.2-10.2) with a normal differential; hemoglobin of 13.6 (RR, 13.2-17.5); hematocrit of 38.8% (RR, 38.7-48.3); and a platelet count of 183 K/L (RR, 151-355). Rare atypical lymphoid cells were identified on peripheral smear; however, flow cytometry did not identify a clonal B lymphocyte population. Computed tomograms of the chest,
abdomen, and pelvis revealed an enlarged spleen and low-grade adenopathy in the splenic hilum, mesentery, and retroperitoneum. A bone-marrow biopsy was conducted for histologic examination and immunophenotyping studies. The bone-marrow core biopsy specimen revealed a prominent sinusoidal infiltrate of atypical CD201 B cells. Flow cytometric analysis of the bone-marrow aspirate confirmed a monoclonal B-lymphocyte population expressing CD19, CD20, CD22, CD45, FMC-7, and l immunoglobulin light chain. This population was negative for CD5, CD10, CD11c, CD23, and CD38. Histologic and immunophenotypic findings in the skin and bone marrow were diagnostic of an extranodal marginal zone B-cell lymphoma with widespread cutaneous disease. The patient was evaluated by specialists both in dermatology and hematology and by specialists in oncology, with dermatology follow-up. Aside from pruritus, the patient was asymptomatic for lymphoma, and systemic chemotherapy was deferred in the absence of systemic symptoms. For the cutaneous disease, the patient received 21 treatment sessions over 3 months of narrowband ultraviolet (UV) B phototherapy, ranging from 175 to 785 mJ/cm2, which produced complete resolution of
322 Case reports
J AM ACAD DERMATOL FEBRUARY 2010
the pruritus and a clearing of lesions. The patient continues to be monitored quarterly for recurrence of symptoms.
DISCUSSION The classic histopathologic appearance of mycosis fungoides is characterized by a bandlike lymphoid infiltrate in the dermis, epidermotropism, and intraepidermal collections of atypical lymphocytes.1 Cutaneous B-cell lymphomas typically consist of nodular to diffuse lymphoid infiltrates with relative sparing of the epidermis.1 However, as observed in our patient, both primary and secondary cutaneous B-cell lymphomas can mimic mycosis fungoides histologically, albeit rarely. Only a few such cases have been reported in the English-language medical literature. Glusac et al2 conducted a randomized review with masked assessment of hematoxylin-eosin slides from 77 patients with primary and secondary cutaneous Bcell lymphomas and 20 patients with nonmycosis fungoides and cutaneous T-cell lymphomas. Patients were categorized as having B-cell or T-cell lymphomas on the basis of morphologic structure alone. Of the 77 patients with B-cell lymphomas, 4 were incorrectly categorized as having T-cell lymphomas because of histologic features of atypical lymphoid infiltrate limited to the papillary dermis, epidermotropism, interstitial involvement, and lack of a grenz zone. All 4 cases demonstrated atypical lymphoid infiltrates in the dermis and intraepithelial lymphocytes. Subsequent analysis of immunohistochemical staining confirmed the presence of dermal lymphocytes that were predominantly monoclonal B lymphocytes with variable scattered T cells. In one patient, T lymphocytes alone infiltrated the epidermis. The other patients had mixed B lymphocytes and T lymphocytes in the epidermis, with one patient having epidermotropic lymphocytes that were mainly B cells. Three of these 4 patients were identified as having large-cell lymphomas, whereas one patient had a mixed-cell lymphoma. Chui et al3 described a patient who presented with a pruritic rash over the trunk and proximal arms and legs. A skin biopsy specimen showed a dense bandlike infiltrate of small round lymphocytes with abundant clear cytoplasm, prominent epidermotropism, and absent spongiosis. The diagnosis was presumed to be mycosis fungoides. Immunophenotypic studies, however, revealed a B-cell phenotype for most of the dermal and intraepithelial lymphocytes that expressed CD20 but were negative for CD10 and CD23. Scattered nodules of small CD201 lymphocytes were present in a bone-marrow biopsy specimen. Both skin and bone-marrow biopsy findings
were consistent with those for extranodal marginal zone lymphoma, and the patient was treated systemically with cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy. Metzman et al4 described one patient with B-cell chronic lymphocytic leukemia in whom erythematous, scaly, and mildly atrophic plaques developed on the thighs, back, and axillae that were characteristic of the patch and plaque stages of mycosis fungoides. A biopsy specimen of skin from the thigh demonstrated a bandlike infiltrate of small to medium lymphocytes in the papillary dermis and focal epidermotropism. Immunophenotypic studies showed that half of the dermal lymphocytes expressed CD2 and CD45. Clusters of lymphocytes expressed CD20 but were negative for CD2 and CD45. The CD4 to CD8 ratio was 3 to 1. Polymerase chain reaction revealed an immunoglobulin heavychain gene rearrangement and a germ-line T-cell receptor configuration. These findings corresponded to cutaneous chronic lymphocytic leukemia with a reactive T-cell process that mimicked mycosis fungoides. Landa et al5 reported on one patient with dermatomyositis and primary cutaneous B-cell lymphoma who presented with noduloulcerative disease of the lower extremities. Histologic findings showed a diffuse infiltrate of small and medium lymphocytes in the dermis that extended into the subcutaneous fat. Microscopic findings of epidermotropism and angioinvasion were suggestive of a T-cell neoplasm. Immunophenotyping studies showed that the lymphoid infiltrate in the superficial dermis and at the dermal-epidermal junction was composed primarily of T cells. However, atypical lymphocytes in the reticular dermis revealed a B-cell phenotype. Gene rearrangement studies confirmed a clonal B-cell population. Our report demonstrates that cutaneous B-cell lymphomas can show epidermotropic lymphoid infiltrates, which are typically more characteristic of cutaneous T-cell lymphomas. Our findings are consistent with those in other reports of rare B-cell lymphomas that noted a T-cell pattern mimicking mycosis fungoides. Although architectural features are often used to distinguish among different types of cutaneous lymphomas, they can sometimes cause confusion and may be misleading without the support of additional immunophenotyping studies. Epidermotropism is also found in other cutaneous diseases, including reactive inflammation and Langerhans cell histiocytosis.6 Thus, it is important to use caution when interpreting architectural features in lymphoproliferative malignancies involving the skin and to consider verifying such findings with immunohistochemical studies.
J AM ACAD DERMATOL
Case reports 323
VOLUME 62, NUMBER 2
To our knowledge, this case also represents the first published report of epidermotropic cutaneous B-cell lymphoma in which the patient had a complete clinical response to narrowband UVB phototherapy after 3 months of treatment. Narrowband UVB phototherapy recently became a first-line treatment for early-stage mycosis fungoides and has been used for psoriasis, atopic dermatitis, vitiligo, lichen planus, and other inflammatory skin disorders.7-9 Its mechanism of action may be related to the inhibition of antigen presentation9 and to the direct cytotoxicity to T lymphocytes,10 as noted in some studies on narrowband UVB phototherapy in T-lymphocytee mediated dermatoses. Our findings in this case suggest that narrowband UVB phototherapy may also have a suppressive effect on B lymphocytes. Narrowband UVB phototherapy appears to be an effective, well-tolerated treatment for the early cutaneous manifestations of epidermotropic cutaneous B-cell lymphoma.
REFERENCES 1. Willemze R, Jaffe ES, Burg G, Cerroni L, Berti E, Swerdlow SH, et al. WHO-EORTC classification for cutaneous lymphomas. Blood 2005;105:3768-85.
2. Glusac EJ, Kindel SE, Soslow RA, Smoller BR. Evaluation of classic architectural criteria in non-mycosis fungoides cutaneous lymphomas. Am J Dermatopathol 1997;19:557-61. 3. Chui CT, Hoppe RT, Kohler S, Kim YH. Epidermotropic cutaneous B-cell lymphoma mimicking mycosis fungoides. J Am Acad Dermatol 1999;41:271-4. 4. Metzman MS, Stevens SR, Griffiths CE, Ross CW, Barnett JM, Cooper KD. A clinical and histologic mycosis fungoides simulant occurring as a T-cell infiltrate coexisting with B-cell leukemia cutis. J Am Acad Dermatol 1995;33:341-5. 5. Landa NG, Zelickson BD, Kurtin PJ, Winkelmann RK. Primary Bcell lymphoma with histologic features of a T-cell neoplasm. J Am Acad Dermatol 1992;26:288-92. 6. Slater DN. Cutaneous lymphoproliferative disorders: an assessment of recent investigative techniques. Br J Dermatol 1991;124:309-23. 7. Brazzelli V, Antoninetti M, Palazzini S, Prestinari F, Borroni G. Narrow-band ultraviolet therapy in early-stage mycosis fungoides: study on 20 patients. Photodermatol Photoimmunol Photomed 2007;23:229-33. 8. Gambichler T, Breuckmann F, Boms S, Altmeyer P, Kreuter A. Narrowband UVB phototherapy in skin conditions beyond psoriasis. J Am Acad Dermatol 2005;52:660-70. 9. Pavlotsky F, Nathansohn N, Kriger G, Shapiro D, Trau H. Ultraviolet-B treatment for cutaneous lichen planus: our experience with 50 patients. Photodermatol Photoimmunol Photomed 2008;24:83-6. 10. Ozawa M, Ferenczi K, Kikuchi T, Cardinale I, Austin LM, Coven TR, et al. 312-Nanometer ultraviolet B light (narrow-band UVB) induces apoptosis of T cells within psoriatic lesions. J Exp Med 1999;189:711-8.