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.

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.

Treatment of periocular infantile hemangiomas with propranolol: case series of 18 children.

PURPOSE: To study the efficacy of propranolol in the treatment of periocular infantile hemangiomas (IHs). DESIGN: Retrospective interventional case series. PARTICIPANTS: Eighteen children presenting periocular IH with occlusion of the pupil, anisometropic astigmatism, proliferating eyelid IH, or cosmetically disfiguring periocular IH. METHODS: All patients received treatment with propranolol started at 0.5 mg/kg/day with an incremental increase by 0.5 mg/kg/day every 4 days, up to a maximum of 2 to 3 mg/kg/day. Complete eye examinations and serial photographs were obtained before, during, and after treatment. Doppler ultrasound and magnetic resonance imaging performed pre- and post-treatment were compared when available. MAIN OUTCOME MEASURES: Evolution of the treated IH was evaluated with respect to astigmatism, amblyopia, and size of the lesion. RESULTS: The IH size decreased in 17 of 18 patients. We noted a greater reduction when treatment was administered during the proliferative phase of growth of IHs. At the conclusion of treatment, none of our patients had amblyopia. The mean value of amblyogenic astigmatism (n = 7) decreased from 2.71 diopters (D) pretreatment to 1.03 D post-treatment. On radiology, 8 patients had significant regression of the lesion size of their IH and 1 patient had a limited progression. Propranolol had to be temporarily discontinued in only 1 patient because of symptomatic hypotension. CONCLUSIONS: Propranolol seems to be an effective modality of treatment for periocular IH. It seems to be most efficacious when initiated in the proliferative phase of IH but may be beneficial even in the later stage. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

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.

Unilateral aquagenic keratoderma treated with botulinum toxin A.

BACKGROUND: Aquagenic keratoderma is a rare transient disease that occurs after water immersion and disappears shortly after drying. Most cases involve the palms and fingers bilaterally but it can also affect the soles. Few cases have been associated with drugs but its pathogenesis remains unclear. MAIN OBSERVATION: We report a 60-year-old man with a 30-year-history of aquagenic keratoderma of the right palm without associated hyperhidrosis or history of drug intake. After unsuccessful treatment with 15% aluminium chloride hexahydrate gel, botulinum toxin A injections led to significant improvement within 2 weeks. CONCLUSIONS: To our knowledge, this case is the first report of idiopathic unilateral aquagenic keratoderma in the medical literature. It is the third report of successful treatment with botulinum toxin A which is in favor of a role of sweat glands in the pathogenesis of aquagenic keratoderma.

Lymphangiosarcoma complicating extensive congenital mixed vascular malformations.

Pediatric hepatic angiosarcoma is a very rare malignant vascular tumor. A few cases have shown pediatric hepatic angiosarcoma occurring on a background of preexisting vascular lesions. We report the case of a newborn girl who presented extensive limbs and upper trunk cutaneous mixed vascular malformations at birth. These malformations were associated with thrombocytopenia. Cutaneous biopsies revealed complex vascular malformations with a significant lymphatic component. Compressive body suit therapy led to regression of the limbs' cutaneous vascular malformations. At the age of 9 months, the patient presented multiple heterogeneous hepatosplenic nodules. Aggressive treatment with prednisone, vincristine, and hepatosplenic embolizations resulted in initial improvement of the hepatosplenic lesions for few months, followed by an increase of the lesions with failure of response to treatment despite adding alpha-interferon-2b to treatment. The patient died at the age of 19 months. The autopsy's pathological examination revealed a hepatic-based angiosarcoma with plurimetastatic dissemination to the spleen, lungs, peritoneum, pleura, mesenteric linings as well as the serosa of the stomach and small intestine. Multiple cutaneous and visceral complex capillaro-lymphatico-venous malformations were also identified. We hypothesize that these multiple extensive mixed vascular malformations were associated with chronic lymphedema which probably predisposed to the development of the angiosarcoma in our patient.

Childhood linear IgA bullous disease induced by trimethoprim-sulfamethoxazole.

BACKGROUND: Linear IgA bullous disease (LABD) is a rare mucocutaneous autoimmune subepidermal blistering disease that can affect children mostly of pre-school age. As many as two-thirds of LABD are related to drug ingestion, particularly certain antibiotics, non-steroidal anti-inflammatory drugs and diuretics. MAIN OBSERVATION: We describe a 3-year-old boy who presented a CMV infection followed by LABD induced by trimtheporim-sulfametoxazole. To our knowledge, this is the first reported case of trimethoprim-sulfamethoxazole that was confirmed by a rechallenge. CONCLUSIONS: Most cases of drug-induced LABD are patients being treated with multiple systemic drugs that could induce the LABD. In the lack of suitable alternative treatment, the identification of the causative drug can be achieved by a rechallenge under close medical surveillance.