The triptych of mixed histiocytosis: a systematic review of 105 cases and proposed clinical classification.

Histiocytoses are one of the ultimate diagnostic challenges that every physician face at least once in his/her life. Giving their protean manifestation and differentiated therapeutic needs, histiocytosis requires extensive characterization and multidisciplinary management. Mixed histiocytosis is an emerging group of syndromes defined by the overlap of Langerhans cell histiocytosis and another histiocytic disorder of different type. Despite rare, it may account for up to a fifth of systemic histiocytosis patients in some series. In this work, we comprehensively review for the first time the clinical, radiological, histopathological and molecular features of mixed histiocytosis in children and adults. Moreover, we propose a clinical classification in three groups that differentiate patients with systemic involvement and worse overall survival to other groups with more localized manifestations and indolent behavior, wanting to ease their recognition and treatment. Interestingly we also found that mixed histiocytosis harbor BRAFV600E mutations with a higher frequency comparing to all other histiocytoses, and may therefore benefit of specific inhibitory drugs.

Feline progressive histiocytosis: a retrospective investigation of 26 cases and preliminary study of Ki67 as a prognostic marker.

Feline progressive histiocytosis (FPH) is an uncommon and infrequently reported cutaneous histiocytic proliferative disorder, whose clinical presentation is solitary or multiple cutaneous nodules and papules, with late-course internal metastasis. We describe herein the clinical, epidemiologic, histologic, and immunohistochemical features of this entity, and document the outcome of FPH based on a retrospective study of 26 cases. Female and male cats were affected equally. Lesions were evident either as solitary (16 of 26 cases) or multiple (10 of 26 cases) nonpruritic and alopecic nodules or plaques, preferentially located on the legs and extremities (73%). Follow-up was complete for 19 cats, and ranged from 41 to 1,449 d. Nine died of FPH with a median overall survival of 96 d (range: 41-238 d). The disease recurred in 14 cats after surgical excision of the nodules, and the median disease-free survival was 175 d (range: 21-1,449 d). Five of the 26 cats were alive at the end of the study, and 4 had no progression of the disease. Histologically, lesions were characterized by poorly circumscribed, unencapsulated histiocytic infiltration of dermis and subcutis. Epitheliotropism was observed in 11 (42%) cats. Atypical histiocytes diffusely and consistently expressed MHC II, CD18, and Iba1. Statistically significant higher E-cadherin expression was observed in epitheliotropic cases compared to non-epitheliotropic cases. A negative correlation between overall survival and proliferation index was evident, thus suggesting Ki67 as a promising prognostic marker.

[Rosai-Dorfman disease: Diagnosis and therapeutic challenges]. / La maladie de Destombes-Rosai-Dorfman : évolution du concept, classification et prise en charge.

Rosai-Dorfman disease (RDD) was first described by the French pathologist Paul Destombes in 1965. It frequently affects children or young adults and is characterized by the presence of large histiocytes with emperipolesis. More than 50 years after this first description, the pathogenesis of this rare disease is still poorly understood. The revised classification of histiocytoses published in 2016 identified various forms of RDD, from familial RDD to IgG4-associated RDD. Almost 90% of the patients with RDD have cervical lymph nodes involvement although all the organs may virtually be involved. Outcomes are typically favorable. Treatments may be necessary in case of compression or obstruction, and are not well codified. The main therapeutic strategies rely on surgery, radiotherapy, steroids, immunosuppressive drugs or interferon-alpha and cladribine.

Pediatric histiocytoses in the United States: incidence and outcomes.

BACKGROUND: Histiocytoses are rare disorders affecting the pediatric population. MATERIALS AND METHODS: Surveillance, Epidemiology, and End Results database was searched for pediatric cases (<20 y old) of histiocytosis diagnosed between 1973 and 2010. Demographics, clinical characteristics, and survival outcomes were analyzed using standard statistical methods. Class I disease (Langerhans cell histiocytosis) and class III (malignant histiocytosis) were included in the data set. RESULTS: A total of 828 cases were identified. Overall incidence was 0.142/100,000 persons per annum. Incidence was highest in younger children and those of Asian or Native American descent. Class III disease had a higher incidence versus class I. Adolescents tended to present with class III, whereas young children presented with class I. Disseminated disease was present in most cases of class III, whereas class I had more localized cases. Surgical excision was more likely to be performed in class I. Overall median survival was 349 mo. Patients 15-19 y old and children<1 y old had the worst outcomes. Class I had higher survival compared with class III, which had a median survival of 33 mo. Cases with hematologic spread carried the worst prognosis. Surgical excision conferred a survival advantage while radiation had no effect. Survival improved over the study period. Gender and race had no association with survival. CONCLUSIONS: Class I disease had localized cases and showed benefit from surgical intervention. Class III disease had a higher incidence and was associated with disseminated disease and lower survival. Radiation therapy did not affect survival. Overall survival increased over the previous 40 y.

Histiocitosis. Experiencia en España / Histiocytosis. Experience in Spain

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Slowly progressive lymphohistiocytic meningoencephalomyelitis in 21 adult cats presenting with peculiar neurological signs.

Twenty-one cats presented with a history of slowly progressive neurological signs characterised by a stiff extended tail, behavioural changes, and spastic and ataxic gait. All cats had outdoor access and lived in the same geographical rural area in north-east Scotland. Histological findings were consistent with lymphohistiocytic meningoencephalomyelitis. Immunohistochemistry ruled out 15 pathogens and showed a significant expression of the interferon-inducible Mx protein, suggesting an as yet unidentified infective or environmental immunogenic trigger as the possible causative agent. The late age at onset (mean 9 years), the very slow progression of clinical signs (mean 11 months) and the peculiar clinical presentation (particularly the posture of the tail) have not been reported previously in cats with lymphohistiocytic meningoencephalomyelitis.

Toxicity and carcinogenicity studies of 4-methylimidazole in F344/N rats and B6C3F1 mice.

4-Methylimidazole (4MI) is used in the manufacture of pharmaceuticals, photographic chemicals, dyes and pigments, cleaning and agricultural chemicals, and rubber. It has been identified as a by-product of fermentation in foods and has been detected in mainstream and side stream tobacco smoke. 4MI was studied because of its high potential for human exposure. Groups of 50 male and 50 female F344/N rats were fed diets containing 0-, 625-, 1,250-, or 2,500 ppm 4MI (males) or 0-, 1,250-, 2,500-, or 5,000 ppm 4MI (females) for 106 weeks. Based on the food consumption the calculated average daily doses were approximately 30, 55, or 115 mg 4MI/kg body weight to males and 60, 120, or 250 mg 4MI/kg to females. Survival of all exposed groups of males and females was similar to that of the control groups. The mean body weights of males in the 1,250- and 2,500 ppm groups and females in the 2,500- and 5,000 ppm groups were less than those of the control groups throughout the study. Feed consumption by 5,000 ppm females was less than that by the controls. Clonic seizures, excitability, hyperactivity, and impaired gait were observed primarily in 2,500- and 5,000 ppm females. The incidence of mononuclear cell leukemia in the 5,000 ppm females was significantly greater than that in the controls. The incidences of hepatic histiocytosis, chronic inflammation, and focal fatty change were significantly increased in all exposed groups of male and female rats. The incidences of hepatocellular eosinophilic and mixed cell foci were significantly increased in 2,500 ppm males and 5,000 ppm females. Groups of 50 male and 50 female B6C3F1 mice were fed diets containing 0-, 312-, 625-, or 1,250 ppm 4MI for 106 weeks. Based on the food consumption the calculated average daily doses were approximately 40, 80, or 170 mg 4MI/kg body weight to males and females. Survival of all exposed groups of males and females was similar to that of the control groups. Mean body weights of males and females in the 1,250 ppm groups and that in the 312- and 625 ppm females were less than those of the control groups. Feed consumption by exposed groups of male and female mice was similar to that by the controls. The incidences of alveolar/bronchiolar adenoma in all exposed groups of females, alveolar/bronchiolar carcinoma in 1,250 ppm males, and alveolar/bronchiolar adenoma or carcinoma (combined) in 1,250 ppm males and 625- and 1,250 ppm females were significantly greater than those in the control groups. The incidence of alveolar epithelial hyperplasia was significantly increased in the 1,250 ppm females. 4MI is carcinogenic inducing alveolar/bronchiolar adenoma and carcinoma in male and female mice. 4MI may also induce mononuclear cell leukemia in female rats.

Cutaneous reactive histiocytosis in dogs: a retrospective evaluation of 32 cases.

Thirty-two cases of canine cutaneous histiocytosis were retrospectively evaluated. Median age at onset was 4 years. Lesions included nodules and plaques affecting the head/face, trunk and limbs, and erythema, swelling and depigmentation of the nasal planum/nares. Systemic involvement was not ruled out in all cases. All dogs had complete resolution of dermatological lesions after initial treatment (median 45 days). Initial treatment included prednisone +/- antibiotics (12 of 32 dogs), prednisone and tetracycline/niacinamide (four of 32), prednisone and azathioprine (three of 32), tetracycline/niacinamide +/- vitamin E/essential fatty acids (six of 32), antibiotics +/- antihistamines (three of 32), cyclosporine and ketoconazole (one of 32), topical therapy (two of 32), and no treatment (one of 32). Seventeen dogs received maintenance therapy which consisted of tetracycline/niacinamide +/- vitamin E/essential fatty acids (12 of 17), cyclosporine/ketoconazole (two to three times a week) (two of 17), azathioprine daily (one of 17), prednisone/azathioprine (two times a week) (one of 17), and prednisone daily (one of 17). Median follow up was 25 months. Nine dogs had a recurrence of cutaneous histiocytosis (median days to recurrence 130 days), with seven of nine having more than one recurrence. At study completion, six dogs were deceased (no lesions at the time of death) and 26 of 32 were alive with no lesions. Ten of 26 dogs were on maintenance treatment (eight tetracycline/niacinamide, one azathioprine, one vitamin E). Previous dermatological disease and season had no detectable influence on recurrence. Recurrence was significantly more likely in dogs with nasal planum/nares lesions than dogs without these lesions. Tetracycline/niacinamide was an effective treatment option for dogs in this study population.

Pregnancy loss after first-trimester viability in women with sickle cell trait: time for a reappraisal?

OBJECTIVE: The purpose of this study was to evaluate the obstetric outcomes and pathologic findings in women with sickle cell trait. STUDY DESIGN: In this retrospective case control study, pregnant women with sickle cell trait were studied over a 4-year period (2001-2005). The women who were delivered at > 16 weeks of gestation were compared with a cohort group of subjects with normal hemoglobin levels, and the placentas were sent for pathologic evaluation. RESULTS: A total of 180 pregnancies were studied with a like number of control patients. Subjects who had sickle cell trait demonstrated shorter average duration of pregnancy (233 +/- 45 days vs 255 +/- 34 days; P < .001) and lower birth weight (2114 +/- 1093 g vs 2672 +/- 942 g; P < .001). The rate of fetal death was significantly higher among study group patients (3.5% vs 9.7%; P = .015) when compared with the control group. Additionally, in study women, acute ascending amniotic infection and meconium histiocytosis were noted much more frequently. Sickling in the intervillous space and decidual vessels that were not associated with artifactual change was also found among patients sickle cell trait. CONCLUSION: Patients with sickle cell trait appear to be at increased risk for fetal loss compared with women with normal hemoglobin levels, and placental abnormalities may play a causal role.

[CT of the temporal bone in the study of the inner ear structures in detection of the causes of neurosensory hypoacusis]. / KT visochnoi kosti v izuchenii struktur vnutrennego ukha i vyiavlenii prichin neirosensornoi tugoukhosti.

Computed tomograms of the inner ear structures (n=175) of 150 patients (age 0-75 years) with unaffected temporal bones were studied in detail. It is shown that polyposition CT of the temporal bone is a non-invasive method of visualization of the osseous labyrinth structures: cochlea, vestibule, semicircular canals, aqueducts of the labyrinth and internal acoustic meatus which are reflected on tomograms in 100% cases irrespective of the patient age. Their age-related features are analysed. CT imaging was made in 65 patients with neurosensory hypoacusis of inherited and acquired genesis. The following causes of neurosensory hypoacusis and deafness were revealed: congenital malformation of the labyrinth of Mondini type, common cavity of the labyrinth, cochlear hypoplasia, dysplasia of the vestibule and semicircular canals, a wide aqueduct of the vestibule, stenosis of the internal acoustic meatus, bulboform enlargement of the inner acoustic meatus, neurinoma (schwannoma) of the hearing nerve, Langerhans-cell histiocytosis with affection of the labyrinth capsule, atypical cholesteatoma. The detected changes in the inner ear structures determine further treatment policy.

Childhood cancer registries in Ontario, Canada: lessons learned from a comparison of two registries.

Two childhood cancer registries exist in Ontario. One (POGO) accrues by active registration by pediatric cancer centers, utilizing a histologically based classification system. The other accrues by passive linkage within a larger adult oriented cancer registry (OCR) using a topographically based classification. A reportedly high incidence of childhood cancer based on the latter registry prompted a comparison of the content of the two registries over a 2-year period with the hypothesis that there would be systematic accrual errors. All registrations in both registries for the specified period were reviewed systematically and validated by pathology reports. A small number (2.6%) of registrations in the passive registry were not incident cases, while 2 particular pathologic diagnoses were included in the histologically based registry and not the topographically based registry. These were low grade gliomas and Langerhans cell histiocytosis (LCH). The validated annual incident rate (15.6 per 100000 children 0-14 years of age, excluding LCH) is slightly higher than that reported in other industrialized countries. Ninety-six percent of children aged 0-14 were treated in pediatric oncology centers, while only 46% of adolescents aged 15-17 were treated in such centers. Of the remaining adolescents, more than one-third had lymphomas. This maldistribution of care provided for the young adolescent population may compromise their survival prospects. The results of this study should prompt revision of health care policy and patterns of service delivery.

International comparative study of childhood malignancy comparative study of pediatric malignancy between Kurume and Karachi (K-K Project 1991).

UNLABELLED: A study was undertaken to compare Pediatric Malignancy at Kurume (Japan) and Karachi (Pakistan) with reference to international data collected over the years, in order to identify essential differences between developed and developing conditions and factors influencing the etio-pathogenesis of pediatric cancer. The study was retrospective encompassing all types of cancer in children over a period of three years i-e 1988-1990. Essential factors related to present study were: 1. POPULATION: The population of Karachi is about 10 million while that of Kurume is only half a million. 2. Socio-economic conditions: The average socio-economic condition of people in Karachi is poor while in Kurume it appears to be good. 3. Educational status: Only 25% people in Karachi are educated beyond middle class while Kurume reveals a 100% education up to high school level. 4. Environmental conditions: The environmental conditions of Kurume and surrounding areas are very clean and free from pollution, sewage problems and traffic hazards. Karachi and its surroundings on the other hand pose very serious air and water industries! It was concluded that whereas genetic predisposition predominates, the environmental conditions, educational and socio-economic status of a society immensely influence the pattern and trends of pediatric carcinogenesis.