User login
in about 80% of cases.
“You won’t see blastic plasmacytoid dendritic cell neoplasm listed on our primary cutaneous lymphoma classifications because it’s not technically a primary cutaneous disease,” Brittney K. DeClerck, MD, said during the annual meeting of the Pacific Dermatologic Association. “It’s a systemic disease that has secondary cutaneous manifestations. That’s a very important distinction to make, in terms of not missing the underlying disease associated with what might be commonly first seen on the skin.”
BPDCN is a malignancy of plasmacytoid dendritic cells, which capture, process, and present antigen, and allow the remainder of the immune system to be activated. “They are mainly derived from the myeloid cell lineage, and possibly from the lymphoid line in a subset of cases,” said Dr. DeClerck, associate professor of clinical pathology and dermatology at the University of Southern California, Los Angeles. “They secrete high levels of type I interferons, which is important for antiviral immunity, but they can also be implicated in severe systemic inflammatory diseases, such as systemic lupus erythematosus and systemic sclerosis.”
BPDCN involves the skin in about 80% of cases, she added, “but invariably at some point it involves the bone marrow and has an acute leukemic presentation, whether or not it happens concurrently with what we see on the skin as dermatologists. We also see variable involvement of the peripheral blood, lymph nodes, and the central nervous system.”
The classification of BPDCN has changed over time based on evolving immunohistochemical markers and technologies. For example, in 1995 it was called agranular CD4+ NK cell leukemia, in 2001 it was called blastic NK-cell lymphoma, in 2005 it was called CD4+/CD56+ hematodermic neoplasm, and in 2008 it was called BPDCN (AML subset). In 2016 it became classified as its own entity: BPDCN.
Because of changing nomenclature, the true incidence of the disease is unknown, but according to the best available literature, 75% of cases occur in men and the median age is between 60 and 70 years, “but all ages can be affected,” Dr. DeClerck said. “Cases seem to come in clusters. Our most recent cluster has been in our pediatric population. At Children’s Hospital Los Angeles, we’ve had three cases in the last couple of years. To me, that was a bit unusual.”
She added that 10%-20% of patients will have either a history of, or will develop another, hematologic malignancy, such as myelodysplastic syndrome (MDS), chronic myelogenous leukemia (CML), or acute myelogenous leukemia (AML).
The general prognosis of BPDCN is poor, and the mean time from onset of lesions to an actual diagnosis is about 6.2 months, which underscores the importance of early diagnosis, Dr. DeClerck said. “There can be some nondescript solitary lesions that patients can present with, so don’t hesitate to biopsy.” The median overall survival is less than 20 months, but patients under 60 years of age have a slightly better prognosis.
Clinical presentation
Clinically, the malignancy presents with variable involvement of the skin, bone marrow, lymph nodes, peripheral blood, and central nervous system. “Patients may have one or all of these,” she said. Because 80% of patients have skin lesions, “dermatologists should be aware of this entity in order to communicate with our pathologists to understand that maybe one biopsy isn’t enough. Several biopsies may be required.”
The most common dermatologic presentation of BPDCN is erythematous to deeply violaceous nodules. Other patients may present with infiltrated ecchymotic plaques or petechial to hyperpigmented macules, patches, and plaques. Biopsy reveals a diffusely infiltrated dermis of markedly atypical large cells, but occasionally can be more subtle. “Early lesions may only be perivascular in nature, so going on high power on anything that looks atypical on low power is important in these cases,” Dr. DeClerck said.
The recommended histochemical stains for suspected BPDCN include CD123, CD4, and CD56. “We need to have other stains to rule out other things, such as negative stains that are going to exclude other T cell and B cell processes, and Merkel cell carcinoma, which can express CD56. We also want to have another confirmatory stain because other things can express CD123, CD4, and CD56. Commonly we use TCL1 or TCF4.”
The differential diagnosis of cutaneous findings includes leukemia cutis, mycosis fungoides, NK/T-cell lymphoma, and cutaneous gamma-delta T-cell lymphoma, while the differential diagnosis of biopsy findings includes AML, acute lymphoblastic leukemia, and NK/T-cell lymphoma.
Treatment of BPDCN
Historically, BPDCN was treated with multiagent high-dose chemotherapy. “Patients would frequently respond early but would relapse quickly, progress, and have a poor outcome,” Dr. DeClerck said. Now, first-line therapy is tagraxofusp-erzs (Elzonris) or multiagent chemotherapy based on where the patient is in the course of disease. Tagraxofusp-erzs is an IL-3 conjugated diphtheria toxic fusion protein which binds to CD123, which was approved by the Food and Drug Administration in 2018 for treating BPDCN. After that initial therapy, it is determined whether the patient has a complete response or failed response, she said. “If they have a complete response, they frequently go on to bone marrow transplantation, which is the only curative therapy at this point for these patients.”
According to Dr. DeClerck, an anti-BCL-2 therapy, venetoclax, can be used for patients with BPDCN as well. National Comprehensive Cancer Network (NCCN) guidelines for the treatment of BPDCN can be found on the NCCN website.
Dr. DeClerck emphasized the importance of reviewing biopsy results with a hematopathologist, “because there are complex leukemias that are beyond what dermatopathologists have been trained in.” Once a patient is diagnosed with BPDCN, she recommends rapid referral to a large center for treatment and possible bone marrow transplantation.
Dr. DeClerck disclosed that she is an adviser for tagraxofusp-erzs manufacturer Stemline Therapeutics.
in about 80% of cases.
“You won’t see blastic plasmacytoid dendritic cell neoplasm listed on our primary cutaneous lymphoma classifications because it’s not technically a primary cutaneous disease,” Brittney K. DeClerck, MD, said during the annual meeting of the Pacific Dermatologic Association. “It’s a systemic disease that has secondary cutaneous manifestations. That’s a very important distinction to make, in terms of not missing the underlying disease associated with what might be commonly first seen on the skin.”
BPDCN is a malignancy of plasmacytoid dendritic cells, which capture, process, and present antigen, and allow the remainder of the immune system to be activated. “They are mainly derived from the myeloid cell lineage, and possibly from the lymphoid line in a subset of cases,” said Dr. DeClerck, associate professor of clinical pathology and dermatology at the University of Southern California, Los Angeles. “They secrete high levels of type I interferons, which is important for antiviral immunity, but they can also be implicated in severe systemic inflammatory diseases, such as systemic lupus erythematosus and systemic sclerosis.”
BPDCN involves the skin in about 80% of cases, she added, “but invariably at some point it involves the bone marrow and has an acute leukemic presentation, whether or not it happens concurrently with what we see on the skin as dermatologists. We also see variable involvement of the peripheral blood, lymph nodes, and the central nervous system.”
The classification of BPDCN has changed over time based on evolving immunohistochemical markers and technologies. For example, in 1995 it was called agranular CD4+ NK cell leukemia, in 2001 it was called blastic NK-cell lymphoma, in 2005 it was called CD4+/CD56+ hematodermic neoplasm, and in 2008 it was called BPDCN (AML subset). In 2016 it became classified as its own entity: BPDCN.
Because of changing nomenclature, the true incidence of the disease is unknown, but according to the best available literature, 75% of cases occur in men and the median age is between 60 and 70 years, “but all ages can be affected,” Dr. DeClerck said. “Cases seem to come in clusters. Our most recent cluster has been in our pediatric population. At Children’s Hospital Los Angeles, we’ve had three cases in the last couple of years. To me, that was a bit unusual.”
She added that 10%-20% of patients will have either a history of, or will develop another, hematologic malignancy, such as myelodysplastic syndrome (MDS), chronic myelogenous leukemia (CML), or acute myelogenous leukemia (AML).
The general prognosis of BPDCN is poor, and the mean time from onset of lesions to an actual diagnosis is about 6.2 months, which underscores the importance of early diagnosis, Dr. DeClerck said. “There can be some nondescript solitary lesions that patients can present with, so don’t hesitate to biopsy.” The median overall survival is less than 20 months, but patients under 60 years of age have a slightly better prognosis.
Clinical presentation
Clinically, the malignancy presents with variable involvement of the skin, bone marrow, lymph nodes, peripheral blood, and central nervous system. “Patients may have one or all of these,” she said. Because 80% of patients have skin lesions, “dermatologists should be aware of this entity in order to communicate with our pathologists to understand that maybe one biopsy isn’t enough. Several biopsies may be required.”
The most common dermatologic presentation of BPDCN is erythematous to deeply violaceous nodules. Other patients may present with infiltrated ecchymotic plaques or petechial to hyperpigmented macules, patches, and plaques. Biopsy reveals a diffusely infiltrated dermis of markedly atypical large cells, but occasionally can be more subtle. “Early lesions may only be perivascular in nature, so going on high power on anything that looks atypical on low power is important in these cases,” Dr. DeClerck said.
The recommended histochemical stains for suspected BPDCN include CD123, CD4, and CD56. “We need to have other stains to rule out other things, such as negative stains that are going to exclude other T cell and B cell processes, and Merkel cell carcinoma, which can express CD56. We also want to have another confirmatory stain because other things can express CD123, CD4, and CD56. Commonly we use TCL1 or TCF4.”
The differential diagnosis of cutaneous findings includes leukemia cutis, mycosis fungoides, NK/T-cell lymphoma, and cutaneous gamma-delta T-cell lymphoma, while the differential diagnosis of biopsy findings includes AML, acute lymphoblastic leukemia, and NK/T-cell lymphoma.
Treatment of BPDCN
Historically, BPDCN was treated with multiagent high-dose chemotherapy. “Patients would frequently respond early but would relapse quickly, progress, and have a poor outcome,” Dr. DeClerck said. Now, first-line therapy is tagraxofusp-erzs (Elzonris) or multiagent chemotherapy based on where the patient is in the course of disease. Tagraxofusp-erzs is an IL-3 conjugated diphtheria toxic fusion protein which binds to CD123, which was approved by the Food and Drug Administration in 2018 for treating BPDCN. After that initial therapy, it is determined whether the patient has a complete response or failed response, she said. “If they have a complete response, they frequently go on to bone marrow transplantation, which is the only curative therapy at this point for these patients.”
According to Dr. DeClerck, an anti-BCL-2 therapy, venetoclax, can be used for patients with BPDCN as well. National Comprehensive Cancer Network (NCCN) guidelines for the treatment of BPDCN can be found on the NCCN website.
Dr. DeClerck emphasized the importance of reviewing biopsy results with a hematopathologist, “because there are complex leukemias that are beyond what dermatopathologists have been trained in.” Once a patient is diagnosed with BPDCN, she recommends rapid referral to a large center for treatment and possible bone marrow transplantation.
Dr. DeClerck disclosed that she is an adviser for tagraxofusp-erzs manufacturer Stemline Therapeutics.
in about 80% of cases.
“You won’t see blastic plasmacytoid dendritic cell neoplasm listed on our primary cutaneous lymphoma classifications because it’s not technically a primary cutaneous disease,” Brittney K. DeClerck, MD, said during the annual meeting of the Pacific Dermatologic Association. “It’s a systemic disease that has secondary cutaneous manifestations. That’s a very important distinction to make, in terms of not missing the underlying disease associated with what might be commonly first seen on the skin.”
BPDCN is a malignancy of plasmacytoid dendritic cells, which capture, process, and present antigen, and allow the remainder of the immune system to be activated. “They are mainly derived from the myeloid cell lineage, and possibly from the lymphoid line in a subset of cases,” said Dr. DeClerck, associate professor of clinical pathology and dermatology at the University of Southern California, Los Angeles. “They secrete high levels of type I interferons, which is important for antiviral immunity, but they can also be implicated in severe systemic inflammatory diseases, such as systemic lupus erythematosus and systemic sclerosis.”
BPDCN involves the skin in about 80% of cases, she added, “but invariably at some point it involves the bone marrow and has an acute leukemic presentation, whether or not it happens concurrently with what we see on the skin as dermatologists. We also see variable involvement of the peripheral blood, lymph nodes, and the central nervous system.”
The classification of BPDCN has changed over time based on evolving immunohistochemical markers and technologies. For example, in 1995 it was called agranular CD4+ NK cell leukemia, in 2001 it was called blastic NK-cell lymphoma, in 2005 it was called CD4+/CD56+ hematodermic neoplasm, and in 2008 it was called BPDCN (AML subset). In 2016 it became classified as its own entity: BPDCN.
Because of changing nomenclature, the true incidence of the disease is unknown, but according to the best available literature, 75% of cases occur in men and the median age is between 60 and 70 years, “but all ages can be affected,” Dr. DeClerck said. “Cases seem to come in clusters. Our most recent cluster has been in our pediatric population. At Children’s Hospital Los Angeles, we’ve had three cases in the last couple of years. To me, that was a bit unusual.”
She added that 10%-20% of patients will have either a history of, or will develop another, hematologic malignancy, such as myelodysplastic syndrome (MDS), chronic myelogenous leukemia (CML), or acute myelogenous leukemia (AML).
The general prognosis of BPDCN is poor, and the mean time from onset of lesions to an actual diagnosis is about 6.2 months, which underscores the importance of early diagnosis, Dr. DeClerck said. “There can be some nondescript solitary lesions that patients can present with, so don’t hesitate to biopsy.” The median overall survival is less than 20 months, but patients under 60 years of age have a slightly better prognosis.
Clinical presentation
Clinically, the malignancy presents with variable involvement of the skin, bone marrow, lymph nodes, peripheral blood, and central nervous system. “Patients may have one or all of these,” she said. Because 80% of patients have skin lesions, “dermatologists should be aware of this entity in order to communicate with our pathologists to understand that maybe one biopsy isn’t enough. Several biopsies may be required.”
The most common dermatologic presentation of BPDCN is erythematous to deeply violaceous nodules. Other patients may present with infiltrated ecchymotic plaques or petechial to hyperpigmented macules, patches, and plaques. Biopsy reveals a diffusely infiltrated dermis of markedly atypical large cells, but occasionally can be more subtle. “Early lesions may only be perivascular in nature, so going on high power on anything that looks atypical on low power is important in these cases,” Dr. DeClerck said.
The recommended histochemical stains for suspected BPDCN include CD123, CD4, and CD56. “We need to have other stains to rule out other things, such as negative stains that are going to exclude other T cell and B cell processes, and Merkel cell carcinoma, which can express CD56. We also want to have another confirmatory stain because other things can express CD123, CD4, and CD56. Commonly we use TCL1 or TCF4.”
The differential diagnosis of cutaneous findings includes leukemia cutis, mycosis fungoides, NK/T-cell lymphoma, and cutaneous gamma-delta T-cell lymphoma, while the differential diagnosis of biopsy findings includes AML, acute lymphoblastic leukemia, and NK/T-cell lymphoma.
Treatment of BPDCN
Historically, BPDCN was treated with multiagent high-dose chemotherapy. “Patients would frequently respond early but would relapse quickly, progress, and have a poor outcome,” Dr. DeClerck said. Now, first-line therapy is tagraxofusp-erzs (Elzonris) or multiagent chemotherapy based on where the patient is in the course of disease. Tagraxofusp-erzs is an IL-3 conjugated diphtheria toxic fusion protein which binds to CD123, which was approved by the Food and Drug Administration in 2018 for treating BPDCN. After that initial therapy, it is determined whether the patient has a complete response or failed response, she said. “If they have a complete response, they frequently go on to bone marrow transplantation, which is the only curative therapy at this point for these patients.”
According to Dr. DeClerck, an anti-BCL-2 therapy, venetoclax, can be used for patients with BPDCN as well. National Comprehensive Cancer Network (NCCN) guidelines for the treatment of BPDCN can be found on the NCCN website.
Dr. DeClerck emphasized the importance of reviewing biopsy results with a hematopathologist, “because there are complex leukemias that are beyond what dermatopathologists have been trained in.” Once a patient is diagnosed with BPDCN, she recommends rapid referral to a large center for treatment and possible bone marrow transplantation.
Dr. DeClerck disclosed that she is an adviser for tagraxofusp-erzs manufacturer Stemline Therapeutics.
FROM PDA 2021