Pediatric Cutaneous Hematologic Disorders: Cutaneous Lymphoma and Leukemia Cutis-Experience of a Tertiary-Care Pediatric Institution and Review of the Literature.

BACKGROUND: Cutaneous hematologic malignancies are rare in children, and the literature about them is still sparse. OBJECTIVE: The purpose of our study was to report our experience with pediatric cases of cutaneous hematologic disorders and describe their clinical and histological features. METHODS: Data were retrospectively collected from the histopathologic database of the CHU Sainte-Justine, University of Montreal, Montreal, Canada. All patients up to 18 years of age with a diagnosis of a primary cutaneous lymphoma (including lymphomatoid papulosis), secondary cutaneous lymphoma or cutaneous manifestations of leukemia, followed from 1980 to 2019 at our center were reviewed. RESULTS: Thirty-six patients were included. Age at presentation ranged from birth to 18 years of age (mean 7.83 ± 5.16; median 7.0). Ten different hematologic disorders were identified according to the WHO-EORTC classifications: lymphomatoid papulosis (10 cases), mycosis fungoides (6 cases), anaplastic large cell lymphoma (4 cases), pre-B acute lymphoid leukemia (5 cases), primary cutaneous marginal zone B-cell lymphoma (4 cases), primary cutaneous CD4+medium T-cell lymphoproliferative disorder (1 case), extranodal NK/T-cell lymphoma (1 case), hydroa vacciniforme-like lymphoproliferative disorder (1 case), B-cell lymphoblastic lymphoma (1 case) and acute myeloid leukemia (3 cases). CONCLUSION: The most common subtype of cutaneous hematologic disease in our single institution study was lymphomatoid papulosis (type A and type C), followed by mycosis fungoides. Recognition of this large clinical and histological spectrum by dermatologists is important because diagnosis is often established by biopsy of skin lesions, even in secondary cutaneous cases. Moreover, the clinicopathological correlation is of utmost importance for the final diagnosis of those pathologies.

Kaposiform hemangioendothelioma with overlapping features of rapidly involuting congenital hemangioma and a delayed complication of necrotizing fasciitis.

We report the case of a male infant born at term with kaposiform hemangioendothelioma (KHE) of the right forearm and coagulopathy. Our case was unusual as it involuted leaving subcutaneous atrophy and prominent veins, which are more commonly observed in rapidly involuting congenital hemangioma. At 3 years of age, the child developed recurrent superficial thrombophlebitis localized to the area where the KHE had regressed. Subsequently, he developed necrotizing fasciitis and thrombotic veins in the same location and group A streptococcal septic shock.

A case of segmental stiff skin syndrome treated with systemic losartan.

Stiff skin syndrome (SSS) is a rare, autosomal dominant cutaneous disorder with progressive, symmetric, sclerotic skin changes of the shoulders, hips, and thighs. In a recent publication, a distinct segmental variant of SSS was proposed. In this report we discuss the case of a boy with segmental SSS and review the current literature.

Pigmented purpuric dermatosis: clinicopathologic characterization in a pediatric series.

Pigmentary purpuras (PPs) are a group of chronic disorders of unknown origin seldom described in children. With this study we sought to better characterize PP eruptions, including clinical evolution and management. A retrospective chart review from 2003 to 2013 querying characteristics of children with a biopsy-proven diagnosis of PP in the Centre Hospitalier Universitaire Ste-Justine dermatology clinic (Montreal, Quebec, Canada) was performed. Follow-up was obtained through telephone interviews. Descriptive statistical analysis was used. Of the 17 subjects, 8 were male and the mean age of onset was 9 years. PP was asymptomatic in 11 patients, pruritic in 3, and of cosmetic concern in 3. Schamberg's disease was the most frequent subtype in 12 cases. Resolution of PP was found in 13 cases with a median duration of less than 1 year (range 6 months-9 years). Five patients experienced spontaneous clearing without treatment, and improvement was observed in 75% of cases treated with topical corticosteroids and 100% with narrowband ultraviolet B (nbUVB). No associated disease, significant drug exposure, or contact allergens were found. Those findings support that PPs in children are idiopathic, chronic eruptions that can benefit from watchful waiting, although topical corticosteroids or nbUVB are may be useful if the patient or family desires faster resolution. This study was limited by its small size, its retrospective nature, and selection and recall bias.

Fatal Kawasaki disease with incomplete criteria: Correlation between optical coherence tomography and pathology.

Coronary artery aneurysm is a serious complication of Kawasaki disease (KD). A 3-month-old infant presented with severe KD 27 days after onset of fever. The patient presented with shock, inferolateral ischemia on electrocardiogram and high troponin. Echocardiography showed severe myocardial dysfunction with diffuse coronary dilation and right coronary artery aneurysm. Arterial Doppler demonstrated thrombosis of aneurysmal axillary and iliac arteries. Withdrawal of support was implemented due to multi-organ failure. Post-mortem optical coherence tomography correlated with pathology. The pulmonary artery was normal on OCT and histology. Coronary arteries showed aneurysmal dilatation, with intimal hyperplasia and preserved media on OCT. Pathology confirmed these findings, with destruction of the internal elastic lamina, luminal myofibroblastic proliferation, neovascularization, and partial disappearance of the media. This is the first report of pathologic correlation in KD with OCT at the subacute stage, which adequately identified structural wall changes.

Partially involuting congenital hemangiomas: a report of 8 cases and review of the literature.

BACKGROUND: Congenital hemangiomas have been divided into 2 major subtypes based on clinical behavior: rapidly involuting congenital hemangioma (RICH) and noninvoluting congenital hemangioma (NICH). OBJECTIVE: We describe a clinical subtype of congenital hemangioma that begins as a RICH but fails to completely involute and persists as a NICH-like lesion. We propose the term "partially involuting congenital hemangioma" for this lesion with overlapping features. METHODS: A review of the medical charts, serial clinical photographs, imaging, and biopsies performed on children with a diagnosis of partially involuting congenital hemangioma between 2001 and 2012 at Centre Hospitalier Universitaire Sainte-Justine pediatric dermatology/vascular anomalies clinic was performed. RESULTS: Eight full-term, healthy infants presented at birth with vascular lesions typical of RICH. Affected locations included the head and neck, trunk, or extremities. Size varied from 2.0 × 1.5 cm to 13.0 × 8.5 cm. All had rapid involution during the first 12 to 30 months of life before stabilizing in size and appearance. LIMITATIONS: Only a small number of cases were identified. CONCLUSION: Partially involuting congenital hemangiomas are congenital hemangiomas with a distinct behavior, evolving from RICH to persistent NICH-like lesions. Their recognition and study will help us better understand whether RICH and NICH are indeed separate entities or simply part of a spectrum.

High prevalence of angiotropism in congenital melanocytic nevi: an analysis of 53 cases.

The mechanisms responsible for the development of congenital melanocytic nevi (CMN) have yet to be elucidated. A potential clue to their origin is the observation of angiotropism of nevus cells in CMN. Interestingly, neural crest stem cells (NCSCs), the precursors of melanocytes, demonstrate angiotropism in the embryo. There is accumulating evidence that NCSCs migrate along the external surfaces of vessels during a portion of their journey to the skin. Comparable angiotropism and migration of melanoma cells have been described as extravascular migratory metastasis in melanoma. In this report, we systematically examined for the first time, the frequency of angiotropism in 53 CMN. The lesions originated from 27 females and 26 males with an average age of 9.81 years (range 0.42-28 years). The mean nevus size was 7.43 cm (range 0.3-40 cm). Twenty-seven (50.9%) of the 53 lesions were less than 1.5 cm in diameter. Sixteen nevi (30.2%) were medium sized (1.5-19.9 cm), and 10 CMN (18.9%) were large/giant (>20 cm in diameter). The trunk was the most common location (23/53) followed by the head and neck (17/53). Thirty-eight (71.7%) of the 53 lesions were compound melanocytic nevi, and 15 (28.3%) of the 53 lesions were dermal nevi. In summary, angiotropism was observed in 50 (94.3%) of 53 cases. Consequently, such angiotropism may potentially explain the origin of the precursor cells giving rise to CMN. Further explanations concerning dysregulated growth are clearly needed for the actual appearance of CMN and their physical characteristics.

Fetal cardiac troponin isoforms rescue the increased Ca2+ sensitivity produced by a novel double deletion in cardiac troponin T linked to restrictive cardiomyopathy: a clinical, genetic, and functional approach.

A novel double deletion in cardiac troponin T (cTnT) of two highly conserved amino acids (Asn-100 and Glu-101) was found in a restrictive cardiomyopathic (RCM) pediatric patient. Clinical evaluation revealed the presence of left atrial enlargement and marked left ventricle diastolic dysfunction. The explanted heart examined by electron microscopy revealed myofibrillar disarray and mild fibrosis. Pedigree analysis established that this mutation arose de novo. The patient tested negative for six other sarcomeric genes. The single and double recombinant cTnT mutants were generated, and their functional consequences were analyzed in porcine skinned cardiac muscle. In the adult Tn environment (cTnT3 + cardiac troponin I), the single cTnT3-ΔN100 and cTnT3-ΔE101 mutations had opposing effects on the Ca(2+) sensitivity of force development compared with WT, whereas the double deletion cTnT3-ΔN100/ΔE101 increased the Ca(2+) sensitivity + 0.19 pCa units. In addition, cTnT3-ΔN100/ΔE101 decreased the cooperativity of force development, suggesting alterations in intrafilament protein-protein interactions. In the fetal Tn environment, (cTnT1 + slow skeletal troponin I), the single (cTnT1-ΔN110) and double (cTnT1-ΔN110/ΔE111) deletions did not change the Ca(2+) sensitivity compared with control. To recreate the patient's heterozygous genotype, we performed a reconstituted ATPase activity assay. Thin filaments containing 50:50 cTnT3-ΔN100/ΔE101:cTnT3-WT also increased the myofilament Ca(2+) sensitivity compared with WT. Co-sedimentation of thin filament proteins indicated that no significant changes occurred in the binding of Tn containing the RCM cTnT mutation to actin-Tm. This report reveals the protective role of Tn fetal isoforms as they rescue the increased Ca(2+) sensitivity produced by a cTnT-RCM mutation and may account for the lack of lethality during gestation.

Targetoid hemosiderotic hemangiomas (hobnail hemangiomas) are vascular lymphatic malformations: a study of 12 pediatric cases.

BACKGROUND: Targetoid hemosiderotic hemangioma (THH), also called hobnail hemangioma, is a benign vascular lesion and thought to be of lymphatic origin. OBJECTIVE: We sought to perform a clinicopathologic analysis of cases diagnosed as THH in a tertiary care children's hospital. METHODS: Clinical and histopathologic data were obtained from a chart review of 12 confirmed pediatric cases of THH. To determine the presence or absence of lymphatic vessels in lesional biopsy specimens, we evaluated the expression of the lymphatic endothelial cell marker podoplanin using the D2-40 antibody. Wilms tumor-1 gene immunostaining and Ki-67 proliferation index were also performed to evaluate the proliferative nature of these lesions. RESULTS: Three children had a lesion since birth and 4 had a history of trauma before appearance of the THH. D2-40 immunostaining was positive in every case. Wilms tumor-1 gene immunostaining was negative in 9 cases, focally positive in two cases, and not performed in one case. The Ki-67 proliferation index was very low in all cases studied. LIMITATIONS: The small number of cases and restriction to a pediatric population were limitations. CONCLUSION: Our findings suggest that THH should be classified as a lymphatic vascular malformation.

Connective tissue nevi in children: institutional experience and review.

BACKGROUND: Connective tissue nevi (CTN) are circumscribed hamartomas of the skin in which there is an abnormal mixture of normal components of the dermis that may be sporadic or associated with syndromes such as Buschke-Ollendorff, tuberous sclerosis, and Proteus. OBJECTIVE: We sought to specify the clinical and histologic features of CTN in childhood and to propose a diagnostic approach and updated classification. METHODS: This was a retrospective study in a tertiary pediatric outpatient population, accessing clinical and histopathological records. RESULTS: We classified 114 cases of CTN from 1980 to 2008. LIMITATIONS: The majority of cases were confirmed by histopathological examination. Therefore, our series excludes many CTN that were not biopsied. In addition, follow-up was variable. CONCLUSION: Our series demonstrates the usefulness of a modified classification for CTN. Biopsy should be done when clinical diagnosis is uncertain, or in multiple lesions. When biopsy is performed it should include normal-appearing skin for comparison and, in Buschke-Ollendorff syndrome, limited anterior-posterior x-rays of the hands, wrists, feet, ankles, knees, and pelvis instead of a full skeletal survey.

Extramedullary hematopoiesis secondary to COVID-19: A first case report in a newborn.

A 39 weeks newborn baby was born with blueberry muffin macules and papules on her back. Skin biopsy was performed and showed extramedullary hematopoiesis. The mother who was infected by COVID-19 infection at 35 weeks of pregnancy did not have any other risk factor for extramedullary hematopoiesis, thus making this viral infection the most likely cause of blueberry muffin rash.

p16 expression: a marker of differentiation between childhood malignant melanomas and Spitz nevi.

BACKGROUND: Childhood malignant melanomas frequently present as nodular melanomas with Spitzoid features. Spitz nevus and Spitzoid melanoma overlap clinically and histopathologically and there have been many attempts to differentiate between them. Spitz nevi differ from melanomas by their immunohistochemical pattern of expression of cell cycle and apoptosis regulators such as the p16 protein. OBJECTIVE: The aim of this study was to evaluate in a childhood population the expression of p16 in nodular malignant melanoma of Spitzoid type, Spitz nevi, and a control group of benign compound melanocytic nevi. METHODS: We performed immunohistochemical studies for expression of p16 in 6 Spitzoid malignant melanomas, 18 Spitz nevi, and 12 compound melanocytic nevi in children younger than 18 years. Statistical analysis was used to compare p16 expression, mitotic count/mm(2), and Ki-67 index of childhood nodular malignant melanomas and Spitz nevi. RESULTS: All the childhood melanoma cases were associated with loss of p16 without any correlation with their Breslow thickness whereas all the Spitz nevi and benign melanocytic nevi had strong positive nuclear and cytoplasmic expression of p16 staining. We found a statistically significant difference in p16 expression, mitotic counts, and Ki-67 index when comparing the Spitzoid melanomas with the Spitz nevi. LIMITATIONS: This study is limited by the small number of malignant melanomas, which are known to be rare in childhood. CONCLUSION: p16 Expression in childhood nodular Spitzoid malignant melanomas and Spitz nevi, in conjunction with clinical and histopathological evaluation, may be a useful tool in differentiating between these two entities.

Expression of CD133+ cancer stem cells in childhood malignant melanoma and its correlation with metastasis.

Cancer stem cells expressing CD133 exist in a wide array of tumors and their identification in malignant melanoma may help refine classification, diagnosis and treatment. To study the correlation between CD133 expression in childhood melanoma and lymph node and/or visceral metastasis, we evaluated 12 cases of malignant melanoma and 12 control cases of Spitz nevus occurring in children. Double immunostaining with CD133 and Ki-67 was performed in the cases showing CD133 positivity. Three melanoma patients had lymph node metastasis and only one had multivisceral metastases; CD133 was positive only in these four patients. The Ki-67 index was lower in the CD133(+) cells in comparison with the CD133(-) melanoma cells in three cases. We found no positivity for CD133 in all the Spitz nevi. CD133(+) cancer stem cell expression in childhood malignant melanoma might correlate with lymph node and/or visceral metastasis and may have a low proliferative Ki-67 index that might explain their chemoresistance.

Differentiation of vascular tumors from vascular malformations by expression of Wilms tumor 1 gene: evaluation of 126 cases.

BACKGROUND: Vascular tumors and malformations can be challenging to diagnose. Although they may initially appear very similar, they have distinct clinical courses and management. Wilms tumor 1 (WT1) gene expression has been reported in many different tumors including hematologic malignancies and some solid tumors. OBJECTIVE: We sought to evaluate the expression of WT1 in 126 vascular lesions (64 vascular tumors, one Masson tumor, and 61 vascular malformations). METHODS: Based on the International Society for the Study of Vascular Anomalies classification of vascular anomalies, we studied the expression of WT1 in vascular tumors composed of infantile hemangioma, congenital hemangiomas (non-involuting, rapidly involuting, and not otherwise specified), pyogenic granuloma, tufted angioma, cherry angioma, Kaposi sarcoma, and angiosarcoma. We also studied WT1 expression in vascular malformations composed of angiokeratoma/verrucous hemangioma, combined vascular malformations, venous malformations, glomuvenous malformations, lymphatic malformations/lymphangioma, telangiectasia, and targetoid hemosiderotic hemangioma. RESULTS: All vascular tumors and proliferations had positive WT1 cytoplasmic endothelial immunostaining whereas only 3 vascular malformations were WT1 positive. Moreover the positivity of WT1 in these vascular malformations was focal and involved only re-endothelialized neovessels within thrombi. LIMITATIONS: The low number of malignant vascular tumors is a limitation. CONCLUSIONS: Immunohistochemical detection of WT1 could be a useful tool to routine evaluation of vascular anomalies allowing the distinction of vascular tumors and proliferations from vascular malformations. Staining for WT1 may guide the clinician in difficult cases, as positive results would suggest a proliferative vascular lesion whereas negative results might point to a vascular malformation.

Linear cutaneous lupus erythematosus in children-report of two cases and review of the literature: A case report.

Linear cutaneous lupus erythematosus is an unusual presentation of cutaneous lupus following Blaschko's lines. It is described mostly in children and young adults and is usually not associated with systemic involvement. We report two cases of linear cutaneous lupus erythematosus in children who significantly improved after treatment with hydroxychloroquine in combination with topical corticosteroids and tacrolimus. These rare cases underline the importance of including linear cutaneous lupus erythematosus in the differential diagnosis of blaschkoid inflammatory lesions.