Anatomic distribution of melanocytes in normal nail unit: an immunohistochemical investigation

Very few histologic reports describe normal melanocytes of the nail unit. Previous studies predominantly address the distal nail matrix melanocytes; we found no review of nail-bed melanocytes in the literature. The proximal nail matrix melanocytes are difficult to identify; the cells cannot be identified by L-DOPA staining. More recently, their scarcity was confirmed by immunohistochemistry with a large panel of antibodies directed against melanocytes. We wished to detect the proximal nail matrix dormant melanocytes and compare their density and distribution with that of the other melanocytes in the distal matrix and nail bed and to establish criteria of normality that may help clarify the pathologic features of benign nevoid melanonychia in the nails of whites. A panel of five monoclonal antibodies (MoAbs), including HMB45 and TRP1 directed against antigens localized in early melanosomal vesicles, was investigated in frozen sections of six nail specimens from whites. Both vertical and horizontal sections were assessed to determine the presence of dormant melanocytes. Results showed that the proximal nail matrix melanocytes were clearly identified with MoAbs HMB45 and tyrosinase-related protein-1 (TRP-1). By contrast, melanocytes stained by MoAb against tyrosinase and L-DOPA reaction were evident, especially in the distal matrix. With MoAb TRP-1, the epithelial sheets showed counts of approximately 217+/-84/mm2 in the proximal matrix and of 132+/-34/mm2 in the distal matrix; the nail bed counts were only 45+/-25/mm2. The split epithelial sheets had 103+/-17/mm2 L-DOPA-positive melanocytes in the distal third of the matrix, but only a few of them were detected in the proximal matrix and none were noted in the nail bed. We clearly identified proximal nail melanocytes using MoAb HMB45 and TRP1. The total number of matrix melanocytes can be estimated as approximately 217/mm2. In proximal matrix, the dormant melanocytes compartment was predominant. In the distal matrix, two compartments were identified: a functionally differentiated and a dormant compartment. Contrary to classical opinion, longitudinal melanonychia originates more frequently in the distal matrix, not secondary to the larger melanocyte density but because only the distal matrix contains an active melanin synthesis compartment. Furthermore, the superficial distribution of proximal nail melanocytes in vertical sections showed a histologic feature that may simulate the pagetoid pattern of melanoma in situ.

[Diagnosis of intravascular lymphoma on a muscular biopsy]

Intravascular lymphomatosis is characterized by a proliferation of malignant lymphoid cells within the lumen of arteriola, capillaria or venula. It is a very rare neoplasia (less than 200 cases reported). Many organs can be involved, but preferentially the central nervous system. The diagnosis is sometimes performed only by a post mortem study. We report a case of a 74 year-old man with biological markers of inflammation, progressive dyspnea and myalgia. A muscular biopsy revealed the diagnosis.

Differential SP220K expression in renal carcinoma and oncocytoma cells

SP220K is a newly described serine proteinase which displays guanidinobenzoatase activity in its inactive form and gelatinolytic activity in its active form. SP220K expression was studied in 20 renal clear-cell carcinomas and in a series of renal oncocytomas, a rare benign tumor derived from the kidney tubule epithelium. We provide evidence that SP220K expression, as assessed by guanidinobenzoatase activity, gelatin zymography and Western blot immunodetection, was increased markedly in cancer basolateral membranes compared to kidney cortex controls, whereas no signal was detectable in basolateral membranes from the 5 renal oncocytomas studied. Cytoplasms of carcinoma cells were immunodetected consistently, whereas no expression was seen in oncocytic cells from any of the oncocytomas studied (12/12). Endothelial cells were immunodetected in all 3 tissue types. Our data favor a potential mechanistic relationship between expression of the matrix proteinase SP220K and invasive phenotype in kidney epithelium proliferative processes.

Examination of extraintestinal tissue cysts of Isospora belli

Relapse is common in immunocompetent and immunosuppressed humans infected with Isospora belli and is believed to be associated with the presence of extraintestinal stages. In the present study, we examined this important stage in an AIDS patient using histological, immunohistological, histochemical, and ultrastructural methods to better understand the development and structure of this stage and to develop better means of detecting infections. Antisera made in rabbits to Isospora suis, Toxoplasma gondii, Hammondia hammondi, Sarcocystis neurona, Neospora caninum, and Caryospora bigenetica were tested against I. belli tissue cysts in the avidin-biotin peroxidase complex (ABC) immunohistological test. Most antisera reacted positively in the ABC test at dilutions of 1:100 but not at dilutions of 1:250. Some antisera to N. caninum and H. hammondi reacted positively at dilutions of 1:1,000 in the ABC test. Most reactive antisera stained the tissue cyst wall and not the enclosed zoite. Eight histochemical tests were examined and most were nonreactive with I. belli zoites or tissue cysts. Transmission electron microscopy revealed that the tissue cyst wall was composed of granular material and was directly beneath the parasitophorous vacuole membrane. Zoites were in the center of the tissue cysts and were surrounded by fibrillar material that appeared to originate from the zoite surface. Tubulelike structures were present in the granular tissue cyst wall and in the fibrillar material that surrounded the zoite. Zoites contained a crystalloid body. New findings in the present study consisted of identifying what are probably early tissue cysts that lack a developed tissue cyst wall, demonstrating that more than 1 tissue cyst can occupy a host cell, describing the distribution of micronemes and the shedding of zoite membranes, and identifying tubular structures in the inner tissue cyst wall and inner compartment.

Oral inflammatory pseudotumour: immunohistochemical investigation of a case involving the submandibular gland and review of the literature

Inflammatory pseudotumours (IPs) are rare lesions. Most commonly reported in the lung, they are almost ubiquitous, but few oral cases have been described. Their rapid growth, local invasiveness and recurrence, and their ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI) aspects are confusing and mimic benign or malignant neoplasms. Their recognition and distinction from malignant tumors is of importance but their histopathological diagnosis may represent a challenge. In the case reported involving the submandibular gland, the spindle cells had the immunohistochemical profile of myofibroblasts, broader cells with a larger nucleus were CD68 and/or Mac387 positive and the dense plasmacytic infiltrate was polyclonal. Histopathology of IPs covers a spectrum of appearances according to the cellularity and the degree of fibrosis. The recognition of a variable mixture of three main cell types: histiocytes or macrophages, myofibroblasts or fibroblasts and abundant plasma cells, with low mitotic activity and absence of cytological abnormalities in an ill circumscribed and rather fibrous lesion is recommended for the diagnosis of oral IP.

AIDS-related primary brain lymphomas: histopathologic and immunohistochemical study of 51 cases. The French Study Group for HIV-Associated Tumors

Fifty-one cases of acquired immunodeficiency syndrome (AIDS)-related primary brain lymphomas (AR-PBL) were investigated for clinical characteristics; human immunodeficiency virus (HIV)-associated disorders; histopathologic features; immunophenotype; Epstein-Barr virus (EBV) infection; and, when frozen tissue was available, oncogene rearrangements. AR-PBL occurred late in the course of AIDS and were usually associated with other systemic or cerebral disorders and with a low level of CD4 lymphocytes. All cases were high grade lymphomas according to the Working Formulation or updated Kiel classification, and often displayed a multifocal pattern. Thirty cases were classified as immunoblastic with plasmacytic differentiation, 18 cases were large cell lymphomas with an immunoblastic component or centroblastic polymorphic lymphomas, and 2 were small noncleaved non-Burkitt lymphomas (Working Formulation). This latter category is classified as Burkitt's-like lymphoma in the REAL nomenclature. One case could not be classified because of necrosis. AR-PBL showed a high level expression of activation and adhesion molecules. The presence of EBV was detected in most cases, and, when PCR was used, this was a constant finding. bcl-2 oncoprotein and latent membrane protein-1 (LMP-1) were strongly expressed. None of the tested cases expressed p53, or were rearranged for bcl-2 or c-myc oncogenes. This study confirms the immunophenotypic specificity of AR-PBL, which may reflect the special immune status of the brain.

Cyclophosphamide cystitis as a model of visceral pain in rats: minor effects at mesodiencephalic levels as revealed by the expression of c-fos, with a note on Krox-24

The evoked expression of the immediate-early gene-encoded proteins c-Fos and Krox-24 was used to study activation of mesodiencephalic structures as a function of the development of cyclophosphamide (CP) cystitis in behaving rats. This article is the third of a series and completes previously published data obtained at both spinal and hindbrain levels. CP-injected animals received a single dose of 100 mg/kg i.p. under transient volatile anesthesia and survived for 1-4 h in order to cover the entire postinjection period during which the disease develops. Survival times longer than 4 h were not used owing to ethical considerations. Results from CP-injected groups are compared with those from either noninjected controls or saline-injected animals having survived for the same times as CP-injected ones. Quantitative results come from c-fos expression. At mesodiencephalic levels a high and widespread basal c-fos expression was observed in control animals; maximum staining was observed at the midthalamic level. Four groups of nuclei were identified with regard to the density of staining. The first group included nuclei showing clustered, intensely labeled cells; these areas were restricted in extent and related to the maintenance of circadian rythms (intergeniculate leaf, suprachiasmatic nucleus, dorsal parts of either paraventricular thalamic nuclei or central gray), sleep-arousal cycle (supramamillary nucleus), or changes in arterial pressure (laterodorsal tegmental nucleus). The second group included nuclei showing scattered, moderately labeled cells; these areas were widespread at all rostrocaudal levels and related to either autonomic/neuroendocrine regulations (central gray, lateral habenula, hypothalamus) or motor behavior, orienting reflex and oculomotor coordination (unspecific subdivisions of both colliculi and their adjoining mesencephalic regions, zona incerta dorsal). The third group included nuclei with evenly distributed, faintly labeled cells; these areas, which, with few exceptions, covered almost the entire diencephalon, mainly concerned nuclei of multisensory convergence having functions in either discriminative tasks (laterodorsal and lateroposterior thalamic nuclei) or emotional responses (intralaminar and midline thalamic nuclei). The fourth group included nuclei free of labeling; these were areas that received the bulk of unimodal sensory/motor inputs (central inferior colliculus, pretectal optic nuclei, ventral medial geniculate nucleus, ventral anterior pretectal nucleus, dorsal lateral geniculate nucleus, ventrobasal complex; zona incerta ventral, parafascicular thalamic nucleus) and are thus the most discriminative regarding specific modalities. Variations in staining were of the same magnitude in both saline- and CP-injected animals. A sequential study spanning every postinjection hour revealed maximum staining at 1 h postinjection, which was followed by a progressive, time-related decrease. Increases in the number of labeled cells 1 h postinjection were significant in only a restricted number of nuclei showing low basal expression (Edinger-Westphal nucleus and paraventricular, supraoptic, and lateral hypothalamic nuclei); time-related reductions in staining that were correlated to sleep or quiescence behaviors finally resulted in staining equal to or below that seen in control animals. No structures showed significantly increased staining in relation to the full development of cystitis, i.e., with the increase of visceronociceptive inputs. Comparing the present results with those previously obtained at more caudal levels, it appears that subtelencephalic levels primarily driven by visceronociceptive inputs, i.e., those that increase and/or maintain their activity in parallel with the degree of nociception, are confined to brainstem-spinal cord junction levels and only comprise certain subdivisions of the nucleus of the solitary tract (nucleus medialis, nucleus commissuralis, and ventralmost part of area po

Oral cryptococcosis: case report of salivary gland involvement in an AIDS patient

Salivary cryptococcosis was disclosed at autopsy in an AIDS patient with disseminated C. neoformans infection. H & E staining was not suitable to demonstrate the occurrence of C. neoformans in many tissues; Alcian blue gave the best results.

Liver biopsy is not useful in the diagnosis of mycobacterial infections in patients who are infected with human immunodeficiency virus

Liver biopsy (LB) has been advocated for the detection of mycobacterial infections in patients infected with human immunodeficiency virus (HIV). To determine the effect of the use of this procedure on survival, we compared it terms of yield with histological findings and noninvasive microbiological procedures. We reviewed the cases of 98 patients who underwent 106 LBs as part of the diagnostic screening for fever of unknown origin. LB revealed 17 cases of mycobacterial infection. For all but one patient, the results of at least one noninvasive procedure were positive. In 85 cases where infections were not diagnosed by LB, 17 had infections documented by other procedures. When all culture results are considered, the mean (+/- SD) incubation time to the first positive culture was 15 +/- 5 days, whereas the mean (+/- SD) incubation time to the first positive culture of an LB specimen was 28 +/- 9 days. The survival time was not significantly increased for patients who underwent LB and had positive Ziehl-Neelsen-stained smears; these patients survived a mean (+/- SD) of 12 +/- 11 months, whereas patients with negative smears survived a mean (+/- SD) of 9 +/- 10 months. Noninvasive studies are preferable to LB for the diagnosis of mycobacterial infections in HIV-infected patients.

[Comparative profitability of hepatic biopsy and microbiological tests in patients with HIV infection]

OBJECTIVES

Diagnostic liver biopsy is proposed in HIV-positive patients who present unexplained fever. This invasive procedure is truly useful if it allows establishing a difficult diagnosis or improves survival rate. We conducted a retrospective study to determine the diagnostic and prognostic power of liver biopsy in HIV-positive patients with fever.

METHODS

One hundred thirty-eight liver biopsies were performed in 129 patients. Utility was defined as demonstration of the pathogen or identification of a tumoral process.

RESULTS

The liver biopsy met the utility criteria in 27 cases showing mycobacterial infections (n = 22) and herpes hepatitis, type 1 herpes simplex virus, cytomegalovirus and cryptococcosis infections (n = 1 each). These last 4 diagnoses were also possible with other tests. Comparing non-contributive liver biopsies (n = 111) with those demonstrating hepatic mycobacterial infection (n = 22) showed that the two groups were not different in terms of demographic data. Splenomegalia was more frequent in the non-contributive group (68% vs 37%, p = 0.007) as was superficial lymph node enlargement (45% vs 12%, p < 10(-3)). Laboratory tests were not discriminating. Mycobacterial infection was diagnosed in 22 patients in the non-contributive group. Bacteriological samples were positive for mycobacterium in 20 of the 22 patients in the contributive group. The mean delay to the first positive test for mycobacterium was 15 +/- 8 days compared with 30 +/- 10 days for liver tissue cultures. Mean survival after liver biopsy was 10 months: patients with a positive Ziehl-Neelson stain on the liver biopsy did not have a longer survival (9.7 +/- 7.6 vs 10.2 +/- 10.4 months).

CONCLUSION

In most cases, liver biopsy in HIV-positive patients with fever provides a diagnosis which can be obtained with non-invasive techniques without improving prognosis.

Benign fibrous mesothelioma of the pleura: MR study and pathologic correlation

Benign fibrous mesothelioma of the pleura is a rare tumor of mesodermal origin. We describe the MR findings in three pathologically proven cases. All three tumors were imaged by MR as well-circumscribed lesions with smooth margins in contact with the pleura, but without chest wall invasion. Their low signal intensity on T1- and T2-weighted sequences reflect their fibrous nature. In one case a pedicle connecting the tumor to the chest wall was visualized on a sagittal MR scan. In two cases gadolinium-enhanced T1-weighted gradient echo sequences revealed intense contrast uptake by the tumor correlated with the intratumoral hypervascularization noted by histologic examination. Although the number of cases presented is small, MR seems to be the most accurate imaging modality in the assessment of the diagnosis.

Cervical intra-epithelial neoplasia in women infected with human immunodeficiency virus

OBJECTIVE

To investigate the relationship between human immunodeficiency virus (HIV) and cervical intra-epithelial neoplasia (CIN).

DESIGN

A prospective study to determine the prevalence of cervical intra-epithelial neoplasia in 111 HIV-positive women.

METHODS

In total, 111 HIV + women were enrolled and underwent cervical biopsy and CD4 T-lymphocyte determination. Of the 111 women, 26 (23.4%) had CIN and another 26 (23.4%) had histologic evidence of cervicitis.

RESULTS

No significant difference was found between transmission group, CDC stage of disease, CD4 T-lymphocyte count and pregnancy. There was a significant association with concomitant human papillomavirus (HPV) infection (P < 0.001).

CONCLUSION

Public health measures are needed to provide Papanicolaou smear screening and appropriate clinical follow-up and treatment of women infected with the human immunodeficiency virus.

Cyclophosphamide cystitis as a model of visceral pain in rats. A survey of hindbrain structures involved in visceroception and nociception using the expression of c-Fos and Krox-24 proteins

The evoked expression of the immediate early gene-encoded proteins c-Fos and Krox-24 was used to study activation of hindbrain neurons as a function of the development of cyclophosphamide (CP) cystitis in behaving rats. CP-injected animals received a single dose of 100 mg/kg i.p. under transient volatile anesthesia and survived for 1 to 4 h in order to cover the whole postinjection period during which the disease develops. CP-injected groups included: (1) animals with minor simple chorionic edema, an early characteristic of inflammation (1 h postinjection); (2) animals with well-developed simple chorionic edema (2 h postinjection); (3) animals with mild inflammation (chorionic edema accompanied by epithelial cleavage; 3 h postinjection); and (4) animals with complete inflammation (4 h postinjection). In addition to onset of chorionic edema, the earliest postinjection period also included the general aspects of the nervous reaction consecutive to the injection process (handling, transient volatile anesthesia and postanesthesia awakening, abdominal pinprick, CP-blood circulating effects). Controls included both noninjected animals and saline-injected animals surviving for the same times as CP-injected ones. Quantitative results come from c-Fos expression. It has been shown that: (1) saline injection is a significant stimulus for only nucleus O and central gray pars alpha and nucleus medialis of the dorsal vagal complex; (2) all structures driven by CP injection (nucleus O and central gray pars alpha, locus coeruleus, Barrington's nucleus and parabrachial area mostly in its ventral and lateral subdivisions, dorsal vagal complex, ventrocaudal portion of lateral bulbar reticular formation) responded vigorously shortly after injection, but only two (dorsal vagal complex, ventrocaudal portion of lateral bulbar reticular formation) showed increased or renewed activity when cystitis completely developed, i.e., when noxious visceral inputs reached highest levels. Regarding the sequential activation of these structures in relation to postinjection time, evidence is given that: (1) a large variety of hindbrain structures are differentially involved in either the general reaction consecutive to the injection process or to various degrees of cystitis; (2) these structures extend from the brain-spinal cord to the pons-mesencephalon transitional junction levels; (3) the two structures most powerfully driven by visceronociceptive inputs are also the most caudal ones, being located at the brain-spinal cord junction level; and (4) the dorsal vagal complex could be the main hindbrain visceral pain center, with three particular subdivisions, the nucleus medialis, nucleus commissuralis, and ventralmost part of area postrema, being involved.

[Subcutaneous cysticercosis]

INTRODUCTION

The case of a patient originated from Angola who presented subcutaneous and neurologic cysticercosis is reported.

OBSERVATION

The patient was referred for the etiological diagnosis of recurrent seizures. The diagnosis was made by histologic examination of a subcutaneous lesion.

COMMENTS

We review the clinical characteristics of subcutaneous cysticercosis. The association of subcutaneous nodules and signs of central nervous involvement occurring in a patient originating from an area where cysticercosis is endemic, must be suspected of cysticercosis.

[Umbilical endometriosis. A case report]

Umbilical endometriosis is a rare site of the disease. The authors report a case of umbilical endometriosis only. Umbilical involvement is estimated at 0.5 to 1% of all site of the disease. This is a disorder affecting women of childbearing age, with a mean age of about 40. Medical treatment by progestogens or Danazol is inconstantly and partially effective regarding umbilical endometriosis. Surgical excision remains the only effective treatment: omphalectomy with wide removal of the tumor and reconstruction of an umbilicus. Surgery enables histologic study and, in the presence of suggestive symptomatology, search for and treatment of other genital sites.

Cyclophosphamide cystitis as a model of visceral pain in rats: model elaboration and spinal structures involved as revealed by the expression of c-Fos and Krox-24 proteins

The evoked expression of the immediate early gene (IEG)-encoded proteins c-Fos and Krox-24 was used to monitor spinal visceronociceptive processing that results from cyclophosphamide cystitis in behaving rats. Animals received a single dose of 100 mg/kg i.p. of cyclophosphamide and survived for 30 min to 5 h. Longer survival times were not considered because of ethical considerations. Cyclophosphamide-injected animals developed characteristic behavioral signs in parallel with development of bladder lesions and spinal evoked expression of IEG-encoded proteins. Histological examination of the urinary bladder was used to evaluate the degree of cystitis and as a criterion for selection of groups of animals to be quantitatively analyzed. Controls consisted of freely behaving animals including control (un-injected), sham (saline-injected) or diuretic (furosemide-injected) animals. Behavioral modifications consisted of lacrimation, piloerection, assumption of a peculiar "rounded-back" posture, which was accompanied by head immobility and various brief "crises" (tail hyperextension, abdominal retractions, licking of the lower abdomen, backward withdrawal movements). Abnormal behaviors, which first appeared (lacrimation, piloerection) at the end of postinjection hour 1, progressively increased in severity (rounded-back posture) over the following 90 min to reach a plateau at about postinjection hour 2; the rounded-back posture was maintained up to time of death. Histological modifications of bladder tissue were assessed using a 4-grade scale in a blind setting. The 1st grade consisted of control or sham animals with no bladder lesion; 2nd grade, animals with simple chorionic edema; 3rd grade, animals with chorionic edema associated with mucosal abrasion, fibrin deposit, and onset of polymorphonuclear leukocyte infiltration; 4th grade, animals with complete cystitis corresponding to an increase in severity and spread of all the signs of cystitis described above plus petechial hemorrhage. Simple chorionic edema was observed from 30 min to 3 h postinjection, but with a progressive increase in severity over time. Edema accompanied by epithelial abrasion was observed for animals that survived 3-4 h postinjection; complete inflammation was observed in animals that survived 4-5 h postinjection. The study of c-Fos- and Krox-24-encoded protein expression demonstrated that few lumbosacral spinal areas were specifically involved in the processing of visceral inputs in response to bladder stimulation. These areas were the parasympathetic column (SPN), the dorsal gray commissure (DGC as the caudal extent of lamina X), and superficial layers of the dorsal horn.(ABSTRACT TRUNCATED AT 400 WORDS)

Thyroid spindle epithelial tumor with thymus-like differentiation (the "SETTLE" tumor). An immunohistochemical and electron microscopic study

An intrathyroid primary epithelial spindle-cell tumor with mucous cysts is described in a 9-year-old child. Histologically, this well-circumscribed tumor exhibited a nodular pattern, a prominent spindle cell component with minimal pleomorphism, and well-differentiated mucinous glands within fibrous bands. The spindle cells demonstrated diffuse immunopositivity for cytokeratin and vimentin. Electron microscopy of tissue sections demonstrated that cells contained bundles of cytoplasmic tonofilaments and numerous desmosomes. The light and electron microscopic features and immunohistochemical profile of this tumor were similar to those of recently described thyroid tumors that have been called "SETTLE" tumors (i.e., spindle epithelial tumor with thymus-like differentiation). These uncommon tumors can be considered intrathyroid thymoblastomas and must be regarded as potentially malignant lesions.

[Persistent diarrhea in HIV infected patients: role of Enterocytozoon bieneusi]

OBJECTIVES

To determine the epidemiologic, clinical and aetiologic features of chronic diarrhoea in patients with human immunodeficiency virus (HIV) infection.

METHODS

Between January 1992 and April 1993, all HIV positive patients with chronic diarrhoea were enrolled in a prospective study. There were 46 patients in the study group including 33 (22 homosexuals) in stage C according to the 1993 Centers for Disease Control classification.

RESULTS

Thirty-four pathogenic agents were isolated in 26 of the patients (57%). Enterocytozoon bieneusi was the most frequently found pathogen (11 patients, 24%) followed by Cryptosporidium sp (8 patients). Enterocytozoon bieneusi was found in association with other pathogens in 7 patients. All patients with microsporidiosis were in stage C (p = 0.04) and had a longer duration of diarrhoea (19.6 vs 9.8 weeks, p = 0.03), greater weight loss (9.6 vs 2.1 kg, p = 0.0003) and a lower Karnofsky index (48% vs 67%, p = 0.01). Prophylaxy with dapsone or pyrimethamine during the 3 months prior to inclusion had been more frequent (p = 0.04 and p = 0.05 respectively) in patients without microsporidiosis.

CONCLUSION

Microsporidiosis should be suspected as a probable cause of chronic diarrhoea in HIV positive patients with a CD4 count < 100/mm3. Multiple infections may be a factor leading to treatment failure. Microsporidiosis seems to be linked to homosexual intercourse.

Atypical cutaneous histological features of visceral leishmaniasis in acquired immunodeficiency syndrome

Cutaneous lesions in Mediterranean visceral leishmaniasis (VL) are very unusual, except for the presence of Leishmania organisms in cutaneous Kaposi's sarcoma in patients with acquired immunodeficiency syndrome (AIDS). We have identified two unusual cutaneous histological features of VL in three patients with AIDS not described previously; two had "silent leishmaniasis," and in the third, Leishmania organisms were present in sweat ducts, suggesting transepithelial elimination through eccrine sweat glands and/or eccrine epithelial tropism.

Primary bronchogenic squamous cell carcinoma in children: report of a case and review of the literature

The authors report a case of primary bronchogenic squamous cell carcinoma (SCC) revealed by recurrent pneumonia in an 11-year-old boy. Four years after complete surgical resection followed by external radiotherapy, the patient is currently relapse- and metastasis-free. To our knowledge, this is only the sixth pediatric case of primary bronchogenic SCC reported to date.