An updated approach to the diagnosis of myeloid leukemia cutis

Diagnostic approach to leukemia cutis : A differential diagnostic step-by-step algorithm

OBJECTIVES

Leukemia cutis is a conflicting term to describe neoplastic hematopoietic infiltrates in the skin. Cutaneous myeloid or lymphoid proliferations often present a serious differential diagnostic challenge for pathologists.

METHODS

This review aims to outline the confusion associated with the term leukemia cutis and discuss in detail the foremost common differential diagnoses in daily practice. The review is based on a summary of the relevant literature as well as on the authors' experience.

RESULTS

It addresses precursor cell myeloid and lymphoid tumors that are strictly considered true leukemia cutis but also more mature neoplasms, including some recently described mature extramedullary myeloid proliferations. Finally, a practical, comprehensive stepwise approach combining traditional immunohistochemical marker panels, novel lineage- or mutational-specific markers, and other ancillary tests is suggested to reach an entity-specific diagnosis.

CONCLUSION

The proper combination of ancillary techniques can help the pathologist to provide an accurate diagnosis of these challenging skin lesions.

Organomegalies as a predictive indicator of leukemia cutis in patients with acute myeloid leukemia

BACKGROUND

Leukemia cutis (LC) is an extramedullary acute myeloid leukemia (AML) infiltrate. No previous study has described the clinical characteristics and outcomes of Thai patients diagnosed with AML with LC.

MATERIALS AND METHODS

We conducted a 7-year retrospective case-control study on Thai AML patients at Siriraj Hospital from November 2013 to July 2020. Patients were divided into LC and non-LC groups. Initial clinical presentations and laboratory findings were examined to identify LC-associated factors. Overall survival (OS) and relapse-free survival (RFS) were assessed. Pathological tissues underwent re-evaluation to validate the LC diagnoses.

RESULTS

The study included 159 patients in a 2:1 ratio (106 non-LC and 53 LC). The LC group had a mean ± SD age of 54.3 ± 15.5 years; females were predominant. Three-fifths of the LC patients had intermediate-risk cytogenetics; 20.4% had an adverse risk, and 10.2% had a favorable risk. Most were classified as AML-M4 and AML-M5. Leukemic nodules were the primary finding in 58.5% of the cases, mainly on the legs. In the multivariate analysis of predictive factors associated with LC, organomegalies, specifically hepatomegaly, and lymphadenopathy, remained significant factors associated with LC [OR 4.45 (95%CI 1.20, 16.50); p = 0.026 and OR 5.48 (95%CI 1.65, 18.20); p = 0.005], respectively. The LC group demonstrated a significantly reduced OS (log-rank test p = 0.002) (median OS of 8.6 months vs. 32.4 months). RFS was considerably lower in the LC group (log-rank test p = 0.001) (median duration of 10.3 months vs. 24.4 months in the non-LC).

CONCLUSIONS

AML patients who developed LC tended to experience notably poorer prognoses. Therefore, it is imperative to consider aggressive treatment options for such individuals. The presence of organomegalies in AML patients serves as a strong predictor of the possible occurrence of LC when accompanied by skin lesions.

Chilblain-Like Eruption Unveiling Cutaneous Aleukemic Relapse of Acute Myeloid Leukemia

ABSTRACT

Leukemia cutis corresponds to skin infiltration by malignant hematopoietic cells. It is most commonly reported in acute myeloid leukemia, particularly in subtypes with a monocytic component. Its clinical manifestations are extremely variable, and histopathologic diagnosis of cutaneous leukemic infiltrates may be challenging. We report the first case of cutaneous, that is, extramedullary, aleukemic relapse of acute myeloid leukemia within an unusual chilblain-like eruption that imposed a challenging clinical and histopathologic diagnosis. Primary chilblains are uncommon in the elderly, and a systemic underlying cause should be thoroughly investigated. In patients presenting with atypical chilblains (ie, persistent chilblains developing even without exposure to cold temperatures and/or refractory to therapy) and with a history of hematologic disorders such as leukemias, histopathologic examination is crucial to identify leukemic or aleukemic phases of relapse of underlying leukemia and initiate timely treatment.

Acute myeloid leukemia cutis with KMT2A::MLLT3 fusion presenting with leonine facies

A 63-year-old woman presented with plaques covering 60 % body-surface-area and leonine facies. Blood work showed no diagnostic aberrancies. Skin biopsy contained a malignant CD4+/CD56+ mononuclear cell population concerning for blastic plasmacytoid dendritic cell neoplasm. A later bone marrow biopsy confirmed AML with KMT2A::MLLT10 fusion detected by next-generation sequencing (NGS). This patient's LC preceded blood and marrow based symptoms of AML. NGS of the initial skin biopsy should be considered as part of diagnostic guidelines in cases with LC in the differential as this may have led to earlier diagnosis in this case and future cases.

Leukemia Cutis-The Current View on Pathogenesis, Diagnosis, and Treatment

Leukemia cutis (LC) is defined as the leukemic infiltration of the epidermis, the dermis, and the subcutaneous tissue. Leukemia cutis may follow or occur simultaneously with the diagnosis of systemic leukemia. However, cutaneous lesions are occasionally diagnosed as the primary manifestation of leukemia. Leukemic skin infiltrations demonstrate considerable variation regarding a number of changes, distribution, and morphology. The highest incidence of LC is observed in chronic lymphocytic leukemia, monocytic and myelomonocytic acute myeloid leukemia, and T-cell lineage leukemia. Although the pathogenic mechanism of the invasion of leukemic cells into the skin is not well understood, chemokine receptors and adhesion molecules as well as the genetic characteristics of leukemia are thought to play a role. Leukemic skin lesions may be localized or disseminated and may occur alone or in combination on any site of the skin, most frequently in the trunk and extremities. The most common clinical presentations of leukemia cutis are papules, nodules, macules, plaques, and ulcers. In most patients, the complete or partial resolution of cutaneous infiltrations occurs simultaneously with hematologic remission. However, in patients with resistant disease or recurrent skin infiltration, local radiotherapy can be used. This review presents recent data on the pathogenesis, diagnosis, and treatment of leukemic skin involvement in different types of leukemia.

Leukemia Cutis Presenting as a Morbilliform Eruption: A Case Report and Literature Review

Leukemia cutis (LC) is a broad term that describes the infiltration of neoplastic leukocytes into the skin. Classically, LC is characterized by erythematous papules and nodules. However, LC can have a widely variable presentation. Therefore, it is crucial to maintain a high index of suspicion for LC through a complete clinical assessment, histopathology, and immunohistochemistry to distinguish this entity from other clinical mimickers. Herein, we report a case of biopsy-proven LC presenting as a morbilliform eruption that was initially suspected to be a drug eruption in a child with acute monocytic leukemia.

IRF8 may be a useful marker for blastic plasmacytoid dendritic cell neoplasm, especially with weak CD123 expression

We highlight the utility of interferon regulatory factor 8 (IRF8), a novel marker of monocytic and dendritic cell lineages, in the diagnosis of a case of blastic plasmacytoid dendritic cell neoplasm (BPDCN) presenting initially in the skin. A 60-year-old male with a previous history of myelodysplastic syndrome presented with cutaneous nodules on chest and scalp. A punch biopsy specimen of a skin nodule showed a diffuse dermal infiltrate of atypical mononuclear cells. The neoplastic cells expressed CD4, CD56, CD43, and TdT but showed minimal reaction for TCL-1 and CD123, and were negative for CD34, CD117, and MPO, confounding the diagnosis. IRF8 performed in retrospect was strongly positive. A new punch biopsy specimen of a chest nodule showed the blastoid tumor cells were positive for TCL-1, CD4, and CD56, but dim CD123. Subsequent bone marrow involvement showed blastoid tumor cells with intense positivity for CD123, CD4, and CD56, which was supportive of the BPDCN diagnosis. BPDCN cases with weak or variable CD123 and TCL-1 expression represent a potential diagnostic pitfall. In a recent study, 15 cases of BPDCN showed uniformly strong staining for IRF8, while CD123 was dim or negative in 4 of these 15 cases. We suggest IRF8 may be a useful marker for BPDCN, especially in cases with weak or variable expression of CD123 and TCL1.

Extramedullary Acute Leukemia-Still an Unforeseen Presentation

Myeloid sarcomas (MS) are rare extramedullary (EM) hematological tumors that generally arise during the natural course of acute myeloid leukemia (AML), occurring concomitantly with the onset of systemic leukemia; it can also occur following onset but rarely before. Common sites of EM involvement include the lymph nodes, skin, soft tissue, bone and peritoneum. Herein, we report the case of a 63-year-old man who presented EM AML upon initial diagnosis involving the bone marrow, lymph nodes and skin (leukemia cutis). A diagnosis was made based on immunohistochemistry (IHC). This case presents a diagnostic dilemma due to its atypical presentation and the sites involved. It also highlights the importance of IHC in the diagnosis of EM AML. The potential role of hypomethylating agents and Venetoclax in cases not eligible for hematopoietic stem cell transplant are also discussed.

Shapiro xanthogranuloma: An essential diagnosis for dermatologists and dermatopathologists to recognize to avoid misdiagnosis of a hematopoietic malignancy in infants and neonates

The Shapiro xanthogranuloma is a histopathologic form of xanthogranuloma that shows closely packed monomorphous cells, which can extend into the subcutaneous fat; it usually lacks routine diagnostic features of xanthogranuloma. Herein we describe two cases of Shapiro xanthogranuloma occurring in a neonate and in an infant, which were initially thought to be hematologic malignancies. One patient's presentation as a "blueberry muffin baby" added to the diagnostic confusion. Pediatric dermatologists, dermatologists, and dermatopathologists need to be aware of the Shapiro xanthogranuloma and its clinicopathologic features to avoid misdiagnosis of a hematopoietic malignancy in neonates and infants.

Differentiation syndrome during ivosidenib treatment with immunohistochemistry showing isocitrate dehydrogenase R132H mutation

We report a case of differentiation syndrome in a patient receiving the IDH1 inhibitor ivosidenib, with skin biopsy showing isocitrate dehydrogenase (IDH) R132H-mutated leukemia cutis. A 72-year-old man with IDH1-mutated acute myeloid leukemia (AML), status-post allogeneic cell transplantation, on ivosidenib for 6 months, was admitted for culture-negative neutropenic fever, pink and purpuric plaques and patches on the legs, abdomen and back, edema, hypotension, and shortness of breath. Skin biopsy revealed an infiltrate of atypical, immature, myeloperoxidase-positive mononuclear cells compatible with leukemia cutis or Sweet syndrome. Although dermal edema and interstitial neutrophilic infiltrate with karyorrhexis characteristic of Sweet syndrome were not seen, the atypical cells lacked expression of CD117 and CD34, which were expressed in the original leukemia. Additional immunohistochemical staining of suspected blasts was strongly positive for IDH1 R132H, suggesting a diagnosis of leukemia cutis. As the immunophenotype of blasts in skin infiltrates can significantly differ from the immunophenotype seen in blood and bone marrow, this case shows that mutation-specific antibodies such as anti-IDH1 R132H may be useful to help distinguish malignant from non-malignant infiltrates in the skin. Furthermore, differentiation syndrome may show histopathologic features of leukemia cutis on skin biopsy.

Leukaemia cutis as a specific skin involvement in chronic myelomonocytic leukaemia and review of the literature: Acknowledgments

The skin involvement of myeloid leukaemia is conventionally divided into specific malignant lesions and non-specific benign lesions, and these categories are also applicable in chronic myelomonocytic leukaemia (CMML). According to the 2016 World Health Organization (WHO) classification of tumours of haematopoietic and lymphoid tissues, CMML is defined as a myeloid neoplasm with characteristics of myelodysplastic syndrome (MDS) and myeloproliferative neoplasms (MPNs). As a specific cutaneous sign of extramedullary infiltration, leukaemia cutis (LC) is a rare occurrence in patients with CMML, and only approximately 89 cases have been reported in the literature thus far. The clinical features of LC are varied, and LC in CMML exhibits heterogeneous histopathologic features, with manifestations as cutaneous nodules or papules that are composed of blast cells showing either granulocytic or monocytic differentiation. Skin biopsy and further immunohistochemical examination are essential at the time of diagnosis to evaluate pathological type and determine the clinical course. Generally, once diagnosed as LC in CMML, this unusual skin lesion might be an indicator of transformation to acute myeloid leukaemia (AML) and is associated with a poor prognosis. The main treatment is allogeneic stem cell transplantation (ASCT). Therefore, early diagnosis and accurate identification have important therapeutic and prognostic significance in CMML patients with skin infiltration.

Diagnostic and Therapeutic Considerations for Extramedullary Leukemia

PURPOSE OF REVIEW

The purpose of this review is to summarize the current literature on the presentation, diagnosis, and treatment options available for extramedullary (EM) manifestations of leukemia including myeloid sarcoma (MS) and leukemia cutis (LC).

RECENT FINDINGS

Advanced imaging using 18FDG-PET/CT is an effective screening tool for EM manifestations of leukemia. The role of radiation therapy has been more clearly delineated in the treatment of both MS and LC. FDA-approved targeted agents have improved outcomes in patients with AML but have not demonstrated improvements specifically for EM; however, a checkpoint inhibitor, Ipilimumab, holds promise in impacting local control for the treatment of AML-related EM. EM manifestations of leukemia pose significant therapeutic challenges. Treatment of EM is predicated on multiple factors including the presence of concomitant bone marrow involvement, AML-risk classification, and timing of presentation at initial diagnosis or relapse following systemic therapy.

Diagnostic challenge of aleukemic leukemia cutis preceding acute myelogenous leukemia: A case report

Aleukemic leukemia cutis is a rare condition in which malignant white cells invade the skin before they appear in the peripheral blood or bone marrow. It is often associated with a poor prognosis. The condition presents a diagnostic challenge as its manifestations are quite variable terms of lesion type. It can manifest as papules, nodules, and/or plaques, and in rare cases erythematous macules, blisters, and ulcers. The most commonly affected areas of the body are the lower extremities, followed by the upper extremities, back, trunk, and face. Due to the non-specific presentation of the disease, skin biopsy and comprehensive immunohistochemical testing can be extremely helpful in the diagnostic work-up. We describe a case of leukemia cutis presenting prior to acute myelogenous leukemia that was initially misdiagnosed as hyper-IgG4 disease.

Leukemia Cutis in Chronic Neutrophilic Leukemia Associated with Colony Stimulating Factor 3 Receptor Mutation: Clinical Severity Paralleled with Hematologic Abnormality

Cutaneous lesions of leukemia cutis (LC) by chronic neutrophilic leukemia (CNL) have been merely reported due to the rare occurrences of CNL. Furthermore cutaneous lesions in relation to clinical severity have been far less studied. A 70-year-old man presented with multiple violaceous papules and excoriations on both lower extremities. The diagnosis was LC based on histologic and laboratory evaluation and the origin was elaborated as CNL with the confirmation of colony stimulating factor 3 receptor (CSF3R) mutation. Interestingly, the patient presented clinical severity in a parallel manner to the hematologic abnormality. To the best of our knowledge, there has been no reported case of CSF3R confirmed LC in CNL featuring explicit skin eruption in relation to laboratory findings.

Leukemia Cutis – A Case Report

Leukemia cutis is a specific skin lesion which is characterized by diffuse infiltration of neoplastic cells and can occur in all types of leukemia. Leukemia cutis can have varied cutaneous presentations such as papules, macules, nodules, plaques and ulcers. We report a case of 52-year-old woman who presented with erythematous macules and papules over her trunk, thighs and upper arms. A skin punch biopsy showed monomorphic, perivascular and periadnexal infiltration by the cells positive for CD45, CD15, CD68 and lysozyme. According to the subsequent bone marrow biopsy and immunophenotypic analysis of peripheral blood cells, the diagnosis of acute monocytic leukemia (FAB AML-M5b) was made. In our case, the first clinical sign suggestive of the diagnosis of leukemia was the presence of erythematous macules and papules. Therefore, we believe that leukemia cutis should be taken into consideration in the differential diagnosis of maculopapular rush on the trunk, upper arms and leg

Dermatologic Urgencies and Emergencies: What Every Pathologist Should Know

CONTEXT.—

Fatal dermatologic diseases and ones with high morbidity can occur in the inpatient setting. In such cases, prompt and accurate assessment of a bedside skin biopsy is required. This may be challenging for many pathologists who are not familiar with the complexity of skin pathology and skin terminology within the fields of dermatopathology and dermatology.

OBJECTIVE.—

To provide the pathologist with a practical, up-to-date, and "must-know" reference guide on dermatologic urgencies and emergencies from a real-world perspective, highlighting diagnostic pearls, diagnostic pitfalls, and commonly encountered practice gaps. This review will focus on key diseases with which every pathologist should be familiar, including angioinvasive fungal infections, Stevens-Johnson syndrome/toxic epidermal necrolysis, staph-scalded-skin syndrome, acute graft-versus-host disease, bullous pemphigoid, calciphylaxis, Sweet syndrome and its histiocytoid variant, pyoderma gangrenosum, and leukocytoclastic vasculitis, as well as those in their clinical and histopathologic differential.

DATA SOURCES.—

This review is based on peer-reviewed literature and our personal experiences with these diseases at major academic institutions, including one where a large number of stem cell transplants are performed. This review is unique as it represents collaborative expert opinion from both a dermatopathology and a dermatology standpoint.

CONCLUSIONS.—

This review outlines the critical role that the pathologist plays in the outcomes of patients with dermatologic urgencies and emergencies. Improved patient care will result from prompt and accurate histopathologic diagnoses as well as an open line of communication with the dermatologist.

Cutaneous Leukemic Infiltrates Successfully Treated With Biomodulatory Therapy in a Rare Case of Therapy-Related High Risk MDS/AML

Cutaneous manifestations in hematologic malignancies, especially in leukemia, are not common and may be very variable. Here we report a very unusual case of a patient (female, 70 years old) who was admitted to the hospital in 2016 because of skin lesions on the face, the trunk of the body and the extremities. She had a history of breast cancer in the year 2004 (pT1b, pN0, cM0, L0, V0, R0) which had been resected and treated with adjuvant radiation and chemotherapy (cyclophosphamide, methotrexate, 5-fluorouracile) as well as psoriasis treated with methotrexate and cyclosporine. Because of mild cytopenia a bone marrow aspirate/biopsy was performed showing myelodysplastic syndrome (MDS) with multilineage dysplasia. Cytogenetic review revealed a complex aberrant karyotype denoting adverse outcome. Simultaneously, a skin biopsy could confirm leukemic skin infiltration. Consequently, a therapy with azacitidine was started. After the first cycle the patient developed severe pancytopenia with a percentage of 13% peripheral blasts (previously 0–2%) as well as fever without evidence for infection which was interpreted as progressive disease. Therefore, the therapeutic regimen was changed to a biomodulatory therapy consisting of low-dose azacitidine 75 mg/day (given sc d1-7 of 28), pioglitazone 45 mg/day per os, and all-trans-retinoic acid (ATRA) 45 mg/m2/day per os. After cycle 1 of this combined biomodulatory therapy the patient showed hematologic recovery; besides a mild anemia (hemoglobin 11.1 g/dl) she developed a normal blood count. Moreover, the cutaneous leukemic infiltrates which had been unaffected by the azacitidine ameliorated tremendously after 2 cycles resulting in a complete remission of the skin lesions after cycle 6. In conclusion, we report a very unusual case with cutaneous infiltrates being the first clinical manifestation of hematologic disease, preceding the development of acute myeloid leukemia. While azacitidine alone was ineffective, a combined biomodulatory approach resulted in a complete remission of the cutaneous manifestation.

Cutaneous Hematolymphoid and Histiocytic Proliferations in Children

This article focuses on cutaneous hematopoietic neoplasms that are more likely to be encountered in the pediatric age-group and includes both lymphoproliferative and histiocytic disorders. The cutaneous hematologic disorders in children have a different epidemiologic profile to what is seen during adulthood. Although mycosis fungoides is the most frequent form of cutaneous lymphoma in adults, it is very rare in children. Because lymphoblastic leukemias and lymphomas are more frequent in the pediatric setting, cutaneous leukemic infiltrates are relatively common in this age-group. Similarly, histiocytic disorders are more common in children, particularly Langerhans cell histiocytosis and juvenile xanthogranuloma. Notably, the histiocytic disorders have undergone significant modifications on their nomenclature in the basis of the molecular characteristics that are present in them. A summary of the most frequent cutaneous hematopoietic disorders in children will be discussed further in this review.

Pachyderma in Primary Cutaneous NK and T-Cell Lymphoma and Leukemia Cutis

Background

Pachyderma is defined as severely thickened skin with deep folds and is occasionally observed with primary cutaneous NK and T-cell lymphoma (pCNKTCL), primary cutaneous B-cell lymphoma (pCBCL), and leukemia cutis (LC).

Aim

To describe the clinical, histological, and therapeutic particularities of a series of pCNKTCL, pCBCL, and LC patients with pachyderma.

Results

In a series of pCNKTCL (n = 70), pCBCL (n = 12), and LC (n = 2) patients followed up during 9 years, 6 cases of pachyderma were observed. Pachyderma occurred on the arms (n = 2), thighs (n = 1), forehead (n = 1), and face (n = 2). The mean age of the patients was 69 years (51–82). The stages were erythrodermic (T4) mycosis fungoides (MF) (n = 1), folliculotropic MF (FMF) (n = 2), classic (T2) MF (n = 2), and chronic myeloid leukemia (n = 1). The erythrodermic MF patient with acute pachyderma on the right arm responded rapidly to oral steroids. The other cases were indolent, appeared progressively, and were highly treatment resistant. Histology revealed dense dermal neoplastic infiltration. The immunohistological profile of the pachydermic lesions was similar to common MF and LC.

Conclusion

Pachyderma is an atypical manifestation of MF and LC and may occur on the face (FMF) or the extremities (MF). The rapidly appearing pachyderma may be transitory and responds readily to oral steroids.

Clinicopathologic, Immunohistochemical, and Molecular Features of Histiocytoid Sweet Syndrome

Importance

Histiocytoid Sweet syndrome is a rare histopathologic variant of Sweet syndrome. The nature of the histiocytoid infiltrate has generated considerable controversy in the literature.

Objective

The main goal of this study was to conduct a comprehensive overview of the immunohistochemical phenotype of the infiltrate in histiocytoid Sweet syndrome. We also analyze whether this variant of Sweet syndrome is more frequently associated with hematologic malignancies than classic Sweet syndrome.

Design

This is a retrospective case series study of the clinicopathologic, immunohistochemical, and molecular features of 33 patients with a clinicopathologic diagnosis of histiocytoid Sweet syndrome was conducted in the dermatology departments of 5 university hospitals and a private laboratory of dermatopathology.

Main Outcome and Measures

The clinical, histopathological, immunohistochemical, and follow-up features of 33 patients with histiocytoid Sweet syndrome were analyzed. In some cases, cytogenetic studies of the dermal infiltrate were also performed. We compare our findings with those of the literature.

Results

The dermal infiltrate from the 33 study patients (20 female; median age, 49 years; age range, 5-93 years; and 13 male; median age, 42 years; age range, 4-76 years) was mainly composed of myeloperoxidase-positive immature myelomonocytic cells with histiocytoid morphology. No cytogenetic anomalies were found in the infiltrate except in 1 case in which neoplastic cells of chronic myelogenous leukemia were intermingled with the cells of histiocytoid Sweet syndrome. Authentic histiocytes were also found in most cases, with a mature immunoprofile, but they appeared to be a minor component of the infiltrate. Histiocytoid Sweet syndrome was not more frequently related with hematologic malignancies than classic neutrophilic Sweet syndrome.

Conclusions and Relevance

The dermal infiltrate of cutaneous lesions of histiocytoid Sweet syndrome is composed mostly of immature cells of myeloid lineage. This infiltrate should not be interpreted as leukemia cutis.

Mixed phenotypic acute leukemia with leukemia cutis and neuroleukemiosis

Leukemia cutis and neuroleukemiosis are two rare extramedullary manifestations of acute leukemia. We report a 32-year-old woman with multiple skin lesions and painful peripheral neuropathy. Bone marrow biopsy and skin biopsy confirmed the diagnosis of mixed phenotypic acute leukemia. After induction chemotherapy, she attained marrow remission, her skin lesion resolved completely, and her neurologic symptoms significantly improved.

Bilateral Aleukemic Myeloid Sarcoma of the Eyelids With Indolent Course

Leukemic infiltrates may be seen in the skin in the absence of detectable bone marrow involvement. Leukemia cutis may exceptionally occupy the eyelids. An unusual case of a 58-year-old man presenting bilateral erythematous eyelid lesions, proven to be aleukemic leukemia cutis, is reported. Biopsy was conducted and hematoxylin/eosin stained sections were histologically evaluated. Immunohistochemistry was also performed.Light microscopy revealed cutaneous infiltration by a neoplastic population consisting of medium-sized cells. These cells infiltrated the overlying epidermis leading to focal microulcerations. The morphological and immunohistochemical characteristics of the neoplastic population were compatible with myeloid leukemia cutis. The bone marrow biopsy was normocellular for the patient's age. Although chemotherapy was advised, the patient refused any treatment. He remains free of leukemia or evolution of eyelid lesions approximately 1 year after diagnosis. Leukemia cutis of the eyelids is a rare manifestation of acute leukemia and may remain aleukemic in adults for an indefinite period of time.

Neonatal leukaemia cutis

Neonatal leukaemia cutis is a significant neoplasm that may represent a cutaneous manifestation of systemic leukaemia, usually of myeloblastic type. Rarely, it may be or appear to be limited to skin, in which case it is called neonatal aleukaemic leukaemia cutis. By definition, it presents within the first 4 weeks of life and often has a 'blueberry muffin baby' appearance of magenta coloured nodules affecting almost any area of the skin, usually sparing mucous membranes, palms and soles. This clinical pattern is more commonly associated with neonatal infections such rubella and toxoplasmosis, and may be evident with other neonatal neoplasms such as neuroblastoma. Due to the morbidity associated with chemotherapy and reported cases of spontaneous remission without systemic progression in those with neonatal aleukaemic leukaemia cutis without 11q23 translocation, the authors not treating the child with chemotherapy, but to simply monitor for fading of the violaceous nodules, and watch for possible signs of systemic leukaemia.

Leukemia cutis in a patient with acute monocytic leukemia diagnosed simultaneously with hepatocellular carcinoma: A case study

Acute myeloid leukemia presenting as leukemia cutis (LC) with hepatocellular carcinoma is extremely rare. The current study presents a case of a 53-year-old male with generalized cutaneous nodules on the face and anterior chest wall. Laboratory tests, including bone marrow biopsy revealed acute myelomonocytic leukemia (AML-M4) with skin and tonsilar involvement. Liver magnetic resonance imaging (MRI) revealed a 6-cm mass in hepatic segments 4 and 8, and a liver biopsy demonstrated that hepatocellular carcinoma cells and immature blast cells coexisted. Although LC has been reported in Korea, a case of LC associated with acute myelomonocytic leukemia was diagnosed simultaneously with hepatocellular carcinoma and tonsillar involvement. The present study describes this case with a review of the literature.

Cutaneous infiltrates of acute myelogenous leukemia simulating inflammatory dermatoses

Some cases of specific cutaneous manifestations of acute myelogenous leukemia (AML) may mimic inflammatory dermatoses both clinically and histopathologically, presenting with an inconspicuous maculopapular eruption and with only sparse dermal infiltrates. The authors studied the histopathological and immunohistochemical features of 17 biopsies from 16 patients (11 men and 5 women, age range 15-85 years) presenting with minimal skin infiltrates as the first manifestation of AML or as first sign of recurrence after complete remission of the disease. In all cases, the diagnosis of leukemia has been confirmed by bone marrow examination. Two of these cases had been sent to one of us for second expert consultation. Patients presented with generalized, exanthematic maculopapular eruptions, sometimes with a hemorrhagic note, that were mostly interpreted clinically as drug reactions. Histopathologically, the lesions showed sparse, superficial, and mid-dermal infiltrates with minimal perivascular and periadnexal accentuation. Infiltrating cells consisted mostly of neoplastic monocytoid elements with only few reactive lymphocytes and histiocytes. Immunohistochemical stainings revealed in the majority of cases positivity for CD68 (14 of 16 patients), naphthol chloroacetate esterase (NaSDCl) (7 of 10 patients), and myeloperoxidase (6 of 9 patients). Other markers tested were positive only in a minority of cases. These cases represent a pitfall both in the clinical and in the histopathological diagnosis of cutaneous AML. Accurate morphologic and phenotypic correlation together with a high index of suspicion allows a precise diagnosis in these unconventional cases.

Leukemia cutis: an unusual presentation

Leukemia cutis is the term used for cutaneous manifestations of leukemia, which can have varied clinical presentations. A skin biopsy can help in diagnosing such condition and differentiating it from other skin diseases. We present a case where a 45 years old man presented with diffuse papulovesicular skin lesions mimicking dessiminated herpes. Further workup revealed patient having acute myeloid leukemia (AML-M2) and skin biopsy showed infiltration by myeloblasts. With chemotherapy patient went into remission and skin lesions healed.

Discordant immunophenotypic profiles of adhesion molecules and cytokines in acute myeloid leukemia involving bone marrow and skin

We investigated the role of adhesion molecules in skin involvement by acute myeloid leukemia (AML) using immunohistochemical analysis. Ten paired cases of skin and bone marrow biopsy specimens from patients with myeloid leukemia cutis (MLC) and 15 bone marrow biopsy specimens from patients without MLC were studied with antibodies directed against CD29, CD34, CD54, CD62-L, CD183, and cutaneous lymphocyte antigen (CLA). CLA was expressed in all cases of leukemia whereas CD54 was negative within blasts. CD62-L was expressed in 4 of 10 specimens of marrow infiltrates with MLC and 6 of 10 specimens of matching skin infiltrates; in marrows without MLC, only 2 of 15 were positive. CD29 was expressed in 1 of 10 marrow infiltrate specimens with MLC and 4 of 10 matching skin infiltrate specimens; in marrows without MLC, only 1 of 15 were positive. CD183 was expressed in 1 of 10 marrow infiltrate specimens with MLC and 4 of 10 matching skin infiltrate specimens; in marrows without MLC, CD183 was negative. The gain of CD62-L, CD29, and CD183 expression in bone marrow and skin infiltrates in leukemia cutis, relative to bone marrow infiltrates of cases without MLC, suggests a role for these markers in AML homing to skin.

Immunophenotypic analysis of myeloperoxidase-negative leukemia cutis and blastic plasmacytoid dendritic cell neoplasm

Myeloid leukemia cutis (LC) and blastic plasmacytoid dendritic cell neoplasm (BPDCN) are morphologically indistinguishable malignancies that frequently manifest in the skin. Separating myeloperoxidase-negative LC from BPDCN may be particularly challenging. We identified a panel of immunohistochemical stains to distinguish myeloid LC (23 cases) from BPDCN (12 cases): myeloperoxidase, which stained 7 cases (30%) of LC and 0 cases (0%) of BPDCN; CD56, which stained 12 cases (52%) of LC and all 12 cases (100%) of BPDCN; CD4, which stained 2 cases (9%) of LC and all 12 cases (100%) of BPDCN; CD123, which stained 4 cases (17%) of LC and 10 cases (83%) of BPDCN; and Tcl-1, which stained 2 cases (9%) of LC and 9 (82%) of 11 cases of BPDCN. It is interesting that CD33 was not helpful; it stained 18 (78%) cases of LC and 11 cases (92%) of BPDCN. Our results indicate that a panel that includes CD4, CD56, CD123, and Tcl-1 can appropriately distinguish between these 2 entities.