Mycolactone toxin induces an inflammatory response by targeting the IL-1β pathway: Mechanistic insight into Buruli ulcer pathophysiology

Mycolactone, a lipid-like toxin, is the major virulence factor of Mycobacterium ulcerans, the etiological agent of Buruli ulcer. Its involvement in lesion development has been widely described in early stages of the disease, through its cytotoxic and immunosuppressive activities, but less is known about later stages. Here, we revisit the role of mycolactone in disease outcome and provide the first demonstration of the pro-inflammatory potential of this toxin. We found that the mycolactone-containing mycobacterial extracellular vesicles produced by M. ulcerans induced the production of IL-1β, a potent pro-inflammatory cytokine, in a TLR2-dependent manner, targeting NLRP3/1 inflammasomes. We show our data to be relevant in a physiological context. The in vivo injection of these mycolactone-containing vesicles induced a strong local inflammatory response and tissue damage, which were prevented by corticosteroids. Finally, several soluble pro-inflammatory factors, including IL-1β, were detected in infected tissues from mice and Buruli ulcer patients. Our results revisit Buruli ulcer pathophysiology by providing new insight, thus paving the way for the development of new therapeutic strategies taking the pro-inflammatory potential of mycolactone into account.

Buruli ulcer is a neglected tropical disease occurring mainly in poor rural areas of West and Central Africa. This cutaneous disease is caused by Mycobacterium ulcerans, a bacterium belonging to the same family as M. tuberculosis and M. leprae. The skin lesions are caused by a cytotoxic toxin named mycolactone, also known to act as an immunosuppressor and an anti-inflammatory molecule. However, Buruli ulcer lesions are characterized by a chronic cutaneous inflammation with a recruitment of cellular immune cells trying to counteract M. ulcerans. Our work allows for a reconcilitation of previous observations. We found by in vitro experiment on macrophages that the mycolactone-containing mycobacterial extracellular vesicles produced by M. ulcerans induced the production of IL-1β, a potent pro-inflammatory molecule, while other pro-inflammatory soluble factors are inhibited. We also detected IL-1β protein in a mouse model of M. ulcerans infection as well as in biopsies of Buruli ulcer patients. The pro-inflammatory potential of mycolacone has to be taken into account to understand the full pathophysiology of Buruli ulcer.

[Nagashima-type palmoplantar keratoderma: A little-known palmoplantar keratoderma in Europe]

BACKGROUND

Herein we present a case of palmoplantar keratoderma (PPK) in a young adopted girl of Chinese origin living in France.

OBSERVATION

The patient, aged six years, had presented transgressive PPK since birth, as well as erythema progressing in congestive inflammatory episodes, palmoplantar hyperhidrosis and progressive characteristics (moderate hyperkeratosis in areas of rubbing other than the palms and soles, namely the elbows and knees). Histopathological examination of a skin biopsy revealed a thick epidermis with lengthening and thickening of crests. The epithelium displayed a thick granular layer. Electron microscopy showed hyperorthokeratosis with hypergranulosis and loss of lamellar structure of the keratinosomes, as well as cleavage between corneocytes. Molecular studies showed the presence of two composite heterozygous mutations of the SERPINB7 gene, enabling a diagnosis of Nagashima-type PPK (NPPK) to be made.

DISCUSSION

NPPK is an autosomal recessive disease caused by a mutation in the SERPINB7, a member of the superfamily of serine protease inhibitors. It was described by Nagashima in 1977 with molecular characterisation by Kubo following in 2013. It is the most widespread form of PPK in Asia (with a prevalence of 1.2/10,000 in Japan and 3.1/10,000 in China). It is distinguished from the other PPKs in terms of transgressive soft hyperkeratosis, inflammatory episodes and hyperhidrosis, as well as by its non-progressive nature. In the present case, while the clinical presentation was characteristic, diagnosis was only made thanks to sequencing of a panel of over 50 genes responsible for PPK. The disease is effectively little-known in Europe. This study highlights the increasing importance of diagnostic investigation methods involving the use of gene panels.

[Immunohistochemistry using clone VE1 is an economic, specific and sensitive method for detecting the presence of BRAFV600E mutations in melanoma]

BACKGROUND

Determination of BRAF mutation status is mandatory in the management of patients with inoperable stage IIIC or stage IV melanoma. Currently, molecular biology (MB) has been validated for detecting the presence of BRAF mutations.

OBJECTIVE

To compare the sensitivity, specificity and cost of immunohistochemistry (IHC) (clone VE1) versus BM methods (qPCR and Sanger sequencing).

PATIENTS AND METHODS

All the samples for which BRAF mutation status was requested between March 2013 and February 2015 at the cellular and molecular analysis laboratory of the Angers Hospital were included retrospectively and consecutively. The IHC (clone VE1) and BM analyses were performed with the same formalin-fixed paraffin embedded tumour samples. The cost of these two methods was determined on the basis of the cost for the French Health Insurance.

RESULTS

Two hundred and seven samples were subjected to a determination of BRAF mutational status in IHC and BM. Only one sample was discordant between these two methods (positive in IHC, negative in BM). The sensitivity and specificity of the IHC was 100% and 99.25% respectively. The ratio of the cost of IHC/BM testing was 1:2.1.

CONCLUSION

IHC (clone VE1) is a specific, sensitive and economic method for determining BRAFV600E mutation status. Nevertheless, this method must be validated in order to be integrated into a decisional algorithm, alongside BM methods, to determine whether targeted BRAF-inhibitor therapy is indicated.

High-frequency (20-50 MHz) ultrasonography of pseudoxanthoma elasticum skin lesions

BACKGROUND

In most patients pseudoxanthoma elasticum (PXE) manifests with yellowish cutaneous papules and dermal elastorrhexis on skin biopsy. In a small number of cases there are no skin manifestations on clinical examination, and establishing a diagnosis of PXE in such patients is challenging. High-frequency ultrasonography (HFUS) may be of use in predicting skin areas that would yield a biopsy specimen positive for elastorrhexis.

OBJECTIVES

To describe characteristics of clinically visible PXE skin using HFUS, and to evaluate its relevance for diagnosis.

METHODS

HFUS was performed in a cohort of patients with PXE and in controls at a referral centre. HFUS images of PXE skin were compared with those of other conditions. Five operators blind-scored multiple HFUS images of photoprotected or photoexposed skin from patients with PXE and controls. The diagnostic indices (sensitivity, specificity, likelihood ratios, interobserver agreement) were calculated.

RESULTS

The HFUS changes considered as diagnostic for PXE were primarily oval homogeneous hypoechogenic areas in the mid-dermis. The size of these areas closely matched the extent of the histological changes. The sensitivity and specificity of the diagnostic items and interobserver agreement were high, particularly in photoprotected skin. Dermal hypoechogenicity in PXE could be related to high hydration of connective tissue due to the presence of glycosaminoglycans despite elastic fibre mineralization.

CONCLUSIONS

HFUS provides suggestive images of PXE skin lesions. HFUS should now be studied to determine whether it is a potentially valuable technique for the noninvasive identification of elastorrhexis in patients with PXE in whom skin involvement is clinically minimal or absent.

[Atypical eruptive collagenoma: two cases]

BACKGROUND

Eruptive collagenoma is a rare cutaneous lesion seen in young adults. It consists of asymptomatic, flesh-coloured papules that are usually localised on the trunk and the root of the upper limbs. Herein we report two cases on account of the atypical topography of the lesions and the advanced age of the patients.

CASE REPORTS

Case n 1: a 69-year-old man consulted for firm, whitish papules on the wrists, elbows, popliteal fossae and groin without associated signs, and which first appeared several years earlier. The standard laboratory assessment and ocular fundus test were normal. Case no 2: a 69-year-old woman had very firm, flesh-coloured papules on the trunk and the root of the limbs, which appeared after the age of 40. The results of ocular fundus, cardiovascular investigation and laboratory examinations were normal. The histology of papules was similar in both cases and revealed a nodular zone in the reticular dermis, comprising disorganized collagen bundles and excessive quantities of elastic fibres, without elastorrhexis. This histology was consistent with collagenoma.

DISCUSSION

We report two singular cases that were atypical in terms of patient age and localisation in the flexion folds. Histological analysis of a papule enables a diagnosis of collagenoma to be made. Such analysis usually reveals a hamartoma in which the amount of collagen is increased, with variable quantities of elastic tissue, though often decreased. The principal differential diagnoses are elastoma and pseudoxanthoma elasticum.

An unusual severe vascular case of pseudoxanthoma elasticum presenting as generalized arterial calcification of infancy

Pseudoxanthoma elasticum (PXE) is an autosomal recessive disease affecting tissues rich in elastic fibers such as the skin, retina, and cardiovascular system. Mutations in the ABCC6 gene are known to be causative in most patients. Generalized arterial calcification of infancy (GACI) is characterized by extensive hydroxyapatite deposits in the internal elastic laminae in large and medium-sized arteries, leading to arterial stenoses and early and severe myocardial ischemia. GACI has been found to be primarily caused by mutations in the ENPP1 gene. We report two brothers born to unrelated parents. The elder developed uncomplicated PXE in adolescence and harbored mutations in the ABCC6 gene. The younger child died of a condition strikingly reminiscent of GACI at 15 months of age. This case of GACI was independent of mutations in the ENPP1 gene but was probably related to ABCC6 mutations. We demonstrate that matrix Gla protein and fetuin-A, involved in PXE, are also expressed in this case of GACI. These proteins could act as local and systemic inhibitors to limit the extension of mineralization. This report emphasizes concurrently that ABCC6 may be a relevant candidate gene in some cases of GACI with no mutations in the ENPP1 gene, and that GACI may be an atypical and severe end of the vascular phenotype spectrum of PXE.

[Cutaneous angiosarcoma of the leg without lymphoedema]

BACKGROUND

Cutaneous angiosarcoma is a rare aggressive vascular neoplasm with a poor prognosis, seen chiefly in elderly subjects and usually on the scalp or face. The present case is original because of its localization on the leg without any chronic lymphoedema and because of the long survival period. The treatment modalities are discussed.

CASE REPORT

An 87-year-old woman presented with a rapidly growing large deep-purple ulcerated tumour on the anterior aspect of the leg. In addition, two nodules with a similar aspect appeared on the outer surface of the foot. Histological examination showed vascular channels lined with atypical cells consistent with a diagnosis of angiosarcoma. Computed tomography revealed no metastases. Amputation was performed at the thigh and there was no recurrence 30 months later.

DISCUSSION

The leg is a rare site of cutaneous angiosarcoma. Treatment usually consists of surgical excision with wide margins followed by radiotherapy, but in some cases amputation is unavoidable.

Présentation inhabituelle d’une myofibromatose cutanée infantile en plaque unique ulcérée

INTRODUCTION

Infantile myofibromatosis is a rare fibrovascular-like, isolated or multicentric tumor, occasionally of the bone or an organ and appearing before the age of 2. We report a case of infantile myofibromatosis in a child in an atypical form with a single, ulcerated plaque and having developed after the onset of clusters of papular nodules.

OBSERVATION

An infant was seen in consultation because of asymptomatic papules that had developed on the back. The histological examination of a partial biopsy revealed a histiocytofibromatus aspect and led to the diagnosis of clusters of multiple histiocytofibromatous. One year later, the papular nodules had converged, forming a large plaque with ulcerated center. The progressive extension and the absence of healing prompted surgical exeresis and the final diagnosis of myofibromatosis.

DISCUSSION

Diagnosis of infantile myofibromatosis is difficult histologically and clinically and relies on a clear anatomoclinical confrontation. The clinical aspects are varied. To our knowledge, myofibromatosis with a single ulcerated plaque has never been reported in the literature before.

Lichen nitidus palmoplantaire

BACKGROUND

Lichen nitidus is a rare condition, which may be a cause of palmoplantar hyperkeratosis. We report two cases.

CASE REPORTS

A 53 year-old woman presented with a dry and fissured palmoplantar hyperkeratosis. Histological examination of a biopsy showed the typical features of lichen nitidus. Significant improvement was obtained with acitretin. A few months later, multiple lichen nitidus papules appeared on the limbs and the abdomen. A 67 year-old woman was referred to us for a fissured, disabling palmoplantar hyperkeratosis refractory to topical steroids. Histological examination led to the diagnosis of lichen nitidus. Local PUVA therapy resulted in the cleaning of her lesions. Later, typical papules of lichen nitidus appeared on her elbows.

DISCUSSION

Nineteen cases of palmoplantar localization of lichen nitidus have been described. The features are usually tiny yellow papules but sometimes a non-specific keratoderma resembling chronic eczema. Palmoplantar involvement of lichen nitidus may be isolated or associated with cutaneous lesions on unusual sites. Oral retinoids and local PUVA are effective treatments.

[Pseudolymphomatous folliculitis]

INTRODUCTION

A case of a rare variety of cutaneous pseudo-lymphoma is reported.

CASE REPORT

A 13 Year-old boy presented with a nodule on the nose groove which corresponded histologically to a dense, peri follicular lymphocyte infiltration penetrating the hair. Following partial biopsy, the lesion disappeared within a fortnight.

COMMENTS

Our case report corresponds to the entity described in 1999 in the Japanese. Our case occurred in a Caucasian French adolescent. The papulonodule, usually unique, is composed histologically of a dense, peripilary infiltrate that penetrates and disrupt the hair. The majority of cases have been removed surgically. Those that have not usually disappear following partial biopsy. The individualization of this entity is debatable: the involvement of the hair follicles by the infiltration of pseudolymphomas on the face is frequent and non-specific.

[Pelvic malignant ectomesenchymoma: a case report]

We report the case of a 19 month old boy referred to our institution because of a pelvic tumor initially identified as an embryonal rhabdomyosarcoma and treated with surgery and chemotherapy. Eight years after the initial surgery, a local tumor recurrence with bone metastasis was found. Histological examination and immunohistochemistry showed a double differentiation with both muscular and neuronal cells. This double differentiation was retrospectively found in the initial tumor, then allowing the diagnosis of malignant ectomesenchymoma also called gangliorhabdomyosarcoma. This rare tumor, occurring mainly during childhood, is composed of neuroblasts and / or ganglion cells and of malignant mesenchymal cells (usually rhabdomyosarcomatous cells).

[Endodermal pulmonary tumor resembling a fetal lung]

We report a case of a 56-year-old man who developed a flu-like syndrome associated with weight loss. Chest X-ray revealed a homogeneous round lesion of the lung with sharply defined margins in the central lobe. At pathology, the tumor was found to be an endodermal pulmonary tumor resembling a fetal lung. This uncommon tumor is generally a fortuitous chest X-ray finding seen as a rounded peripheral opacity. Diagnosis is based on pathology examination of the surgical specimen. Complementary investigations are not contributory. Unlike blastoma, a differential diagnosis, prognosis is generally good.

[Granulomatous mycosis fungoides histologically simulating cutaneous sarcoidosis]

BACKGROUND

Granulomatous mycosis fungoïdes is an uncommon mycosis fungoïdes. We report a misleading case initially thought to be cutaneous sarcoidosis.

CASE REPORT

A 34-year-old man developed stationary erythematous plaques on the trunk and members. Pathology reported a sarcoidal aspect. No extracutaneous sarcoidal lesions were found. The lesions resolved with puvatherapy. Five years later, the patient developed a voluminous skin tumor in the scapular area. Pathology reported granulomatous mycosis fungoides. Radiotherapy was given. Other plaques developed on the skin with the same histological aspect as initially and disappeared after local applications of chlormethine. During the clinical course, the patient developed visceral localizations of mycosis fungoides in the abdomen and pelvic nodes which responded to polychemotherapy.

DISCUSSION

Histologically, granulomatous mycosis fungoïdes is defined as the association of epidermotropic T-cell lymphoma with epitheloid and giant cell dermal granulomas and no necrosis. Variants may be misleading when the epitheloid and giant cell aspect predominates, as in our observation. An analysis of 28 reported cases showed no disinction between the clinical features. Clinical course or treatment for granulomatous fungoides mycosis or classical fungoid mycosis. Extracutaneous sarcoidosis is rarely associated. Most likely, there is a tissue reaction to the lymphona.

Experimental validation of an automated edge-detection method for a simultaneous determination of the endocardial and epicardial borders in short-axis cardiac MR images: application in normal volunteers

The goal of this study was to put together several techniques of image segmentation to provide a reliable assessment of the left ventricular mass with short-axis cardiac MR images. No initial manual input was required for this process based on region growing, gradient detection, and adaptive thresholding. A comparison between actual mass and automatic assessment was implemented with 9 minipigs that underwent spin-echo MR imaging. Fifteen normal volunteers were studied with a fast-gradient-echo sequence. The automatic segmentation was then controlled by three trained observers. Actual mass and automatic segmentation were strongly correlated (r = .97 with P < .01). For normal volunteers, the standard error of estimation of the automatic assessment (12 g) compared well with the average myocardial mass (120 +/- 30 g) and the interobserver reproducibility of the manual assessment (9 g). These results allow the application of this method to the quantification of the left ventricular function and mass in clinical practice.

[Compressive dyspnea and dysphagia caused by sclerous cervical cutaneous metastasis disclosing breast carcinoma]

INTRODUCTION

Cutaneous metastases from breast carcinoma are infrequently the first sign of the disease. They usually appear as cutaneous thoracic nodules. We report the case of a cutaneous sclerous metastasis from breast carcinoma revealed by acute compressive dyspnea and dysphagia.

CASE REPORT

A 65 years old woman was admitted for compressive acute dyspnea and dysphagia attributed to the growth of a sclerous cervical isolated metastasis. Investigations revealed rapidly growing low-differentiated primitive breast carcinoma. Chemotherapy induced good clinical response allowing a 27 months survival, in spite of a strong chemodependance.

DISCUSSION

This case-report of a breast carcinoma's metastasis is notable because of its clinical revealing signs (acute compressive dyspnea and dysphagia), clinical aspect, cervical location preceding primitive cancer's clinical expression, and long term survival with treatment. The initial submaxillary location suggest the possibility of a metastasis to submaxillary salivary glands with secondary extension to the skin.

[Measurement of the left ventricular mass using MRI with automatic determination of the endocardial and epicardial contours]

This study describes a method of automatic border detection of the left ventricular endocardium and epicardium associating three methods of segmentation (increase of region, border detection and adaptive threshold), applicable to the evaluation of ventricular mass and volume by magnetic resonance imaging. Despite slight underestimation, the spin-echo sequence used in 9 small pigs provided a value of left ventricular mass close to that observed ex vivo (r = 0.97, SEE = 6.05 g). Clinical validation using a rapid gradient-echo sequence was undertaken and compared with manual border detection carried out by three independent, trained operators. The study population included healthy subjects and patients with global or segmental left ventricular dysfunction with or without ventricular deformation. The correlations between automatic and manual detection were satisfactory both for calculation of left ventricular mass (r = 0.93, SEE = 13 g) and measurement of surfaces (r = 0.91, SEE = 1.4 cm2). The concordance of the two methods was confirmed by the Bland and Altman test. Cardiac magnetic resonance imaging may provide accurate and reproducible measurements of left ventricular mass within acceptable acquisition and image processing times for routine use. Although the clinical value of such a method is accepted both for establishing the prognosis and guiding management, studies of the cost/efficacy ratio should be undertaken to situate magnetic resonance imaging with respect to other non-invasive techniques of investigation of left ventricular function.

Simultaneous and correlated detection of endocardial and epicardial borders on short-axis MR images for the measurement of left ventricular mass

A method was developed for fast, reproducible assessment of left ventricular mass with detection of the endocardial and epicardial borders. The method makes use of short-axis magnetic resonance (MR) imaging in conjunction with an integrated segmentation approach that includes region growing, edge detection, and adaptive thresholding. The mass of the left ventricle in nine Yucatan minipigs was measured ex vivo and compared with the mass as determined in vivo with both full automated segmentation and an interactive process involving two trained observers. The test sample consisted of 59 sections obtained during diastole. There was good correlation between actual mass and both automatically and manually assessed mass. Linear regression analysis showed that the difference between ex vivo measurement and automatic mass assessment (standard error of estimation [SEE] = 5 g) was similar to interobserver variability in interactive mass assessment (SEE = 4 g). Mass assessment with short-axis MR imaging and an integrated segmentation approach does not require location of the ventricular cavity and allows precise delineation of the endocardial and epicardial borders. The results of this experimental study are encouraging for the potential use of this technique in clinical cardiac functional analyses.

Effect of stereotactic implantation of biodegradable 5-fluorouracil-loaded microspheres in healthy and C6 glioma-bearing rats

OBJECTIVE

Poly(lactic acid-co-glycolic acid) (PLAGA) microspheres are promising systems for interstitial chemotherapy of brain tumors. They can be readily implanted by stereotaxy and are biocompatible with the brain, in which they are totally biodegraded within 2 months. 5-Fluorouracil (5-FU) was selected for encapsulation, because this hydrophilic and antimetabolic drug is not directly neurotoxic and does not readily cross the blood-brain barrier. Also, its anticancer activity may be improved by sustained administration. Furthermore, it is a potent radiosensitizer.

METHODS

To study their fate and toxicity, two types of 5-FU-loaded PLAGA microspheres were implanted in healthy rats by stereotaxy. One type presented a fast in vitro release profile (FR), and the second exhibited a slow in vitro release pattern (SR) (100% of the encapsulated 5-FU is released within 72 hours and 18 days, respectively). Periodically, rats were killed for microscopic examination. The efficacy of these microspheres on rat glioma was then evaluated. Seven days after stereotactic implantation of C6 malignant glioma cells in the brain, the rats were treated by intratumoral injection of 5-FU solution, blank microspheres, or 5-FU-loaded microspheres (FR and SR types). The mortality of these treated groups was compared by the log-rank test with that of an untreated group.

RESULTS

After implantation of two types of 5-FU-loaded PLAGA microspheres, no sign of clinical or histological toxicity was observed. Entrapped 5-FU crystals were observed until Days 12 and 20 postimplantation within FR and SR microspheres, respectively, which suggests a longer releasing period in vivo than in vitro. In the therapeutic evaluation, only intratumoral implantation of SR-type 5-FU-loaded microspheres significantly decreased the mortality (P = 0.017).

CONCLUSION

5-FU-loaded PLAGA microspheres were implanted in rat brains without evident toxicity. Histological examination suggested a longer sustained delivery period in vivo than in vitro. Intratumoral implantation of SR-type 5-FU-loaded microspheres decreased the mortality of C6 tumor-bearing rats. This effect can be related to the local and the sustained delivery of the drug, because 5-FU administered systemically is ineffective against brain tumors.

[Overexpression of protein p53 and Barrett esophagus. A frequent and early event in the course of carcinogenesis]

OBJECTIVES AND METHODS

In Barrett's oesophagus, the risk of malignancy is evaluated histologically with the presence of dysplasia. The abnormal expression of p53 protein could represent a useful new marker. The aim of this study was evaluate the abnormal expression of p53 protein in a series of 52 oesophagectomy specimens with Barrett's oesophagus, either non-dysplastic (n = 3), dysplastic (n = 8), or malignant (n = 41). The immunohistochemical study was made on deparaffinized sections with the monoclonal anti-p53 antibody DO7.

RESULTS

The 3 non-dysplastic cases were p53 negative; 1 case of low-grade dysplasia in 5 was positive, as were the 3 cases of high grade dysplasia and 33 of 41 cancers (80%), including 13 superficial cancers in 14 (93%) and 20 invasive cancers in 27 (74%). A common feature was the presence of rare p53 positive crypts in low grade dysplastic areas and non-dysplastic specialized mucosa that surrounded high grade dysplasia and cancers.

CONCLUSIONS

Our results confirm the high frequency of the abnormal expression of p53 protein in cancer developed in Barrett's oesophagus. This expression is a consequence of alterations of the TP53 gene, and has an important role in the carcinogenesis of Barrett's mucosa; it is likely to represent an early event. Prospective studies are needed to evaluate its interest in the surveillance of patients with Barrett's oesophagus.

Fate and biocompatibility of three types of microspheres implanted into the brain

The implantation of polymer devices in the brain that release neuroactive drugs locally and in a controlled manner is gaining increasing interest. The fates and tissue reactions of poly(epsilon-caprolactone), ethylcellulose, and polystyrene microspheres, prepared by the solvent evaporation method, radiosterilized by gamma-irradiation, and stereotactically implanted in rat brain have been studied by routine staining and immunohistochemistry. During the first few days after implantation, a nonspecific astrocytic brain tissue reaction was observed along with a macrophagous-microglial cell reaction typically found following any damage in the central nervous system, except in the presence of certain foreign body giant cells. Nine months into the experiment, microspheres appeared to be engulfed by histiocytic cells. The microsphere cluster was surrounded by a sheath composed of collagen and astrocytic cells. No necrosis was observed, suggesting the absence of toxicity. In some animals, however, an hydrocephalus developed as a result of obstruction of the medial ventricle by some microspheres.

A lymph node interdigitating reticulum cell sarcoma

A 20-year-old woman presented with bilateral cervical, supraclavicular, and mediastinal lymphadenopathy. A nodal biopsy specimen showed a diffuse malignant proliferation of large pleomorphic cells. The ultrastructural features and the antigen phenotype (expression of HLA-DR, CD68, alpha 1-antichymotrypsin, and S100 protein and inconstant reactivity for CD11c, CD15, and peanut agglutinin) were consistent with a derivation from interdigitating reticulum cells. Despite intensive combination chemotherapy with autologous bone marrow transplantation and local irradiation, the patient relapsed in the initial sites of the disease. A review of 12 previous reports of interdigitating reticulum cell sarcomas showed that most of these rare tumors behaved aggressively and were unresponsive to classic intensive chemotherapeutic regimens.

["Tufted angioma". A benign vascular tumor to differentiate with Kaposi sarcoma]

Among recently characterized vascular tumors, tufted angioma or angioblastoma is a benign acquired slowly progressive cutaneous tumor, which most commonly arises in the neck and upper trunk in children and young adults. This case report emphasizes the clinical and histological features of tufted angioma. Light microscopic examination reveals numerous lobules of closely packed capillaries scattered throughout the dermis. Vascular lumina are difficult to define. There are no atypical cells. Familiarity with tufted angioma should prevent this lesion from being misdiagnosed as malignant vascular tumor arising in young persons, especially Kaposi's sarcoma.