Dermatitis Artefacta: A Practical Guide for Diagnosis and Management.

Dermatitis artefacta (DA) is a psycho-dermatologic condition based on patients' behavioral patterns, characterized by an intentional production of cutaneous lesions on their own skin. The clinical presentation can be highly variable. Patients with DA seldom seek psychological support or psychiatric consultation. More often, they seek help from their primary care physician or dermatologist. This review article aims to provide a practical guide for the diagnosis and management of AD and affected patients. A broad literature search was performed using the PubMed and Google Scholar electronic online databases, using key words "dermatitis artefacta", "diagnosis", "management", and "psychodermatology". The search was limited to English and Spanish language articles and was supplemented with themed books and book chapters. DA can occur in a variety of clinical presentations, and physicians should suspect DA in patients with a history of psychiatric disorders or extensive use of healthcare services. The ultimate goal of DA treatment may be a proper referral to mental health services. However, the prognosis is poor even when successful mental health referrals are achieved, with low recovery rates. A useful approach may include the suggestion that a mental health provider can help with the anxiety and the distress generated by the lesions: in this case in this case it will be crucial to discuss this with the mental health provider after obtaining informed consent from the patient. Considering the difficulty in promoting patients' adherence to treatment, the ideal setting for DA treatment is a psycho-dermatologic clinic, where both dermatologic and psychological interventions can be seamlessly integrated.

Individual patient risk of progression of urinary bladder papillary tumors estimated from biomarkers at initial transurethral resection of bladder tumor.

OBJECTIVE: To determine if individual, instead of group, patient progression risk could be predicted using p53, Ki67 and CK20 biomarker percentage values at initial transurethral resection of bladder tumor specimens. METHODS: This was an observational study where biomarkers were measured with no knowledge of tumor outcome. Initial bladder tumor specimens were classified as non-invasive and invasive to sub-epithelium (pT1). Percentages of stained biomarker cells were tested as progression predictors from non-invasive to pT1 and pT1 to pT2. Progression probability was correlated with biomarker percentages resulting in a regression equation. RESULTS: We studied 112 patients (median age = 67, range 37-91, males 83/112 (73%), with median follow-up of 39 months (range 1.7-140). Mean biomarker values were higher in stage pT1 than in non-invasive (all p < 0.001). Cut-off points separating progression from non-progression groups in stage pT1 were higher than in non-invasive for all biomarkers. Correlation R values for progression probability vs. biomarker percentages varied from 0.7 to 0.9 (all p < 0.001), regression slopes from 0.1 to 0.8 and intercepts from 11 to 35. A novel individual progression probability was calculated as the product of biomarker percentage of stained cells and slope, plus the prevalence-adjusted intercept. CONCLUSIONS: Identification of individual risk of progression in patients with non-muscle-invasive bladder tumors was possible using p53- and Ki67-derived progression probability using a regression equation. Combining biomarker-derived progression probability to tumor stage pT1 improves progression to pT2 predictive accuracy.

Molecular Epidemiology of ALK Rearrangements in Advanced Lung Adenocarcinoma in Latin America.

OBJECTIVE: Latin American countries are heterogeneous in terms of lung cancer incidence and exposure to potential carcinogens. We evaluated the frequency and clinical characteristics of ALK rearrangements (ALKr) in Latin America. METHODS: A total of 5,130 lung cancer patients from 10 Latin American countries were screened for inclusion. ALKr detection was performed by fluorescence in situ hybridization (FISH), immunohistochemistry (IHC), and real-time reverse transcriptase-polymerase chain reaction (RT-PCR) to assess method variability. Demographic and clinicopathologic characteristics were analyzed. RESULTS: Among the 5,130 patients screened, 8.4% (n = 433) had nonevaluable FISH tests. Evaluable FISH analyses revealed positive ALKr in 6.8% (320/4,697) of the study population, which included patients from 9 countries. ALKr distribution for each country was: Mexico 7.6% (79/1,034), Colombia 4.1% (10/242), Argentina 6.0% (153/2,534), Costa Rica 9.5% (13/137), Panama 4.4% (5/114), Uruguay 5.4% (2/37), Chile 8.6% (16/185), Venezuela 8.9% (13/146), and Peru 10.8% (29/268). RT-PCR showed high positive (83.6%) and negative (99.7%) predictive values when compared to the gold standard FISH. In contrast, IHC only showed a high negative predictive value (94.6%). CONCLUSIONS: Although there is a clear country and continental variability in terms of ALKr frequency, this difference is not significant and the overall incidence of ALKr in Latin America does not differ from the rest of the world.

Human Periprostatic Adipose Tissue: Secretome from Patients With Prostate Cancer or Benign Prostate Hyperplasia.

BACKGROUND/AIM: Periprostatic adipose tissue (PPAT) directs tumour behaviour. Microenvironment secretome provides information related to its biology. This study was performed to identify secreted proteins by PPAT, from both prostate cancer and benign prostate hyperplasia (BPH) patients. PATIENTS AND METHODS: Liquid chromatography-mass spectrometry-based proteomic analysis was performed in PPAT-conditioned media (CM) from patients with prostate cancer (CMs-T) (stage T3: CM-T3, stage T2: CM-T2) or benign disease (CM-BPH). RESULTS: The highest number and diversity of proteins was identified in CM-T3. Locomotion was the biological process mainly associated to CMs-T and reproduction to CM-T3. Immune responses were enriched in CMs-T. Extracellular matrix and structural proteins were associated to CMs-T. CM-T3 was enriched in proteins with catalytic activity and CM-T2 in proteins with defense/immunity activity. Metabolism and energy pathways were enriched in CM-T3 and those with immune system functions in CMs-T. Transport proteins were enriched in CM-T2 and CM-BPH. CONCLUSION: Proteins and pathways reported in this study could be useful to distinguish stages of disease and may become targets for novel therapies.

Risk of Metachronous Advanced Neoplastic Lesions in Patients with Sporadic Sessile Serrated Adenomas Undergoing Colonoscopic Surveillance.

OBJECTIVES: The risk of developing metachronous advanced neoplastic lesions (ANLs) during surveillance after resection of sessile serrated adenomas (SSAs) has not been quantified. METHODS: Patients with sporadic SSAs resected between 1 April 2007 and 31 December 2009 who underwent surveillance colonoscopy in our institution were prospectively evaluated. Patients with low-risk adenomas (LRAs), high-risk adenomas (HRAs), and negative index colonoscopy (NIC) during the same period were identified using the pathology database and electronic medical records, and were also included as a comparison cohort. The primary outcome was the comparison of the study groups with regard to incidence of metachronous ANLs during surveillance colonoscopy. RESULTS: A total of 185 patients had SSAs, of whom 75 with 101 resected polyps were finally included. The comparison cohort consisted of 564 patients: 140 LRAs (160 polyps), 87 HRAs (478 polyps), and 337 NICs. The overall mean colonoscopy follow-up was for 54.5 months (±s.d. 14). SSA patients with synchronous HRA on index colonoscopy presented a higher incidence rate of metachronous ANL (12.96 per 1,000 person-months) compared with patients with HRA (5.07 per 1,000 person-months), whereas those with synchronous LRA and without synchronous adenoma on index colonoscopy presented a low incidence rate of metachronous ANL (0 and 1.41 per 1,000 person-months, respectively) similar to LRA (1.47 per 1,000 person-months). Among patients with SSA the 3- and 5-year ANL free-cumulative probability was 64.3 and 32.1% in those with synchronous HRA, 100 and 100% in those with synchronous LRA, and 95.1 and 91.7% if no synchronous adenoma was found. CONCLUSIONS: Among patients with resected sporadic SSAs the risk of developing metachronous ANL is influenced by the presence of synchronous HRA on index colonoscopy. Patients with SSAs and synchronous HRA on index colonoscopy require closer surveillance, whereas those with synchronous LRA and those without synchronous adenomas may be followed up in the same way as those with LRAs.

Spinal cord compression secondary to metastasis of malignant chondroid syringoma: case report.

The authors describe a case of spinal cord compression due to an epidural metastasis of malignant chondroid syringoma. Chondroid syringoma is a rare mixed tumor of the skin composed of both epithelial and mesenchymal elements. Although most are benign, malignant forms have been reported. Malignant chondroid syringoma may progress very slowly and the metastatic spread occurs late, appearing years after the original diagnosis. There is only one other report of spinal cord compression secondary to metastasis of malignant chondroid syringoma, which was finally diagnosed by microscopic examination of an autopsy specimen. This 63-year-old woman presented with a 4-week history of progressive paraparesis. Admission MRI of the thoracic spine showed an extradural mass arising from the posterior elements and left pedicle of T-9, which caused posterior compression of the spinal cord. Surgical decompression resulted in resolution of the neurological impairments. The histological results were consistent with metastasis of malignant chondroid syringoma. The patient underwent adjuvant radiotherapy and a favorable outcome was noted at the 2-year follow-up visit. This represents the first reported case of spinal cord compression from a metastasis of a malignant chondroid syringoma histologically confirmed in vivo. The authors' experience in this case suggests that resection followed by radiotherapy might be an acceptable means for achieving short-term, progression-free survival.

Fibrolipomatous hamartoma of the nerve: a clinicopathologic report of 13 cases.

BACKGROUND: Fibrolipomatous hamartoma of the nerve is a rare benign infiltrating condition of peripheral nerves with prominent cutaneous findings that has not being well described in the dermatologic and dermatopathologic literature. OBJECTIVE: We sought to evaluate the clinical and histopathological features of this rare condition. METHODS: We reviewed the clinicopathologic features of 13 cases to delineate their clinical presentation and histopathologic spectrum. RESULTS: All patients presented with unilateral lesions on the thenar areas, fingers, or both. In 7 cases the lesions presented congenitally and in 6 cases the lesions presented sporadically. Histologically, we found 2 patterns that have only been rarely mentioned before including cases with intraneural perineurioma-like features and cases with marked nerve hyperplasia. LIMITATIONS: Only 13 cases were included in our study. CONCLUSIONS: This condition is an uncommon entity. The diagnosis of this disorder can be highly suspected on its macroscopic features. Predilection of the median nerve and the frequent association with macrodactyly are characteristic clinical findings.

An unreported case of pancreatic panniculitis in a liver transplant patient.

Pancreatic panniculitis is an uncommon condition that can occur in association with pancreatic disease. Most of the cases reported to date were associated with acute or chronic pancreatitis and pancreas cancer. Recently, development has been described in kidney transplant patients and secondarily to allograft pancreatitis in a pancreas-kidney transplant recipient. Both findings suggest that immunological processes may be involved in the pathogenesis of this entity. We report for the first time a case of acute pancreatitis associated with pancreatic panniculitis in a patient who underwent a liver transplant 10 months before. A 69-year-old man with a history of epigastric pain of a few days of evolution was presented with painful subcutaneous nodules on both legs. Blood chemistry showed raised serum amylase and lipase levels. Ultrasonography and multislice CT scan were suggestive of an acute pancreatitis. A skin biopsy showed typical features of pancreatic panniculitis which included lobular panniculitis with lipocyte degeneration with ghost cells. The administration of octreotide resulted in both a rapid improvement of symptoms and a disappearance of skin lesions. Liver transplant specialists should be aware that the pancreatic panniculitis could be a manifestation ofpancreas disease in patients who have undergone l ver transplantation.

Tumores glómicos de presentación clínica inusual / Unusual clinical presentation of glomus tumors

El tumor glómico es una neoplasia vascular benigna poco común que suele afectar a adultos jóvenes. La localización más frecuente es el lecho ungueal y se caracteriza por dolor paroxístico, sensibilidad localizada e hipersensibilidad a los cambios de temperatura o presión. Comunicamos dos pacientes con presentación clínica inusual. El primer caso corresponde a una paciente de 50 años de edad, con un tumor glómico subungueal de varios meses de evolución sin la clínica característica, lo que dificultó el diagnóstico. Sólo la resonancia magnética permitió visualizar la lesión. La histopatología de la pieza quirúrgicaconfirmó el diagnóstico. El segundo caso hace referencia a una paciente de 61 años que consultó por un tumor doloroso en brazo derecho, sitio inusual para los tumores glómicos...

Sarcoma mieloide: presentación cutánea de novo / Myeloid sarcoma: de novo cutaneous presentation. Case report and literature review

El sarcoma mieloide (SM), también llamado leucemia mieloide aguda extramedular, tumor extramedular mieloide, sarcomagranulocítico o cloroma, es una neoplasia poco frecuente de células mieloides inmaduras. Compromete con mayor frecuencia piel, tejidos blandos, hueso, periostio y ganglios linfáticos. Puede ser la primera manifestación de la leucemia mieloide aguda(LMA), presentarse simultáneamente o constituir una forma de recaída. El diagnóstico se basa en los hallazgos histopatológicos,en la inmunohistoquímica y el inmunofenotipo, que permiten clasificar diferentes tipos de sarcomas mieloides con diferentes pronósticos. Por lo general el tratamiento y el pronóstico no difieren de la LMA.

A unique galectin signature in human prostate cancer progression suggests galectin-1 as a key target for treatment of advanced disease.

Galectins, a family of glycan-binding proteins, influence tumor progression by modulating interactions between tumor, endothelial, stromal, and immune cells. Despite considerable progress in identifying the roles of individual galectins in tumor biology, an integrated portrait of the galectin network in different tumor microenvironments is still missing. We undertook this study to analyze the "galectin signature" of the human prostate cancer microenvironment with the overarching goal of selecting novel-molecular targets for prognostic and therapeutic purposes. In examining androgen-responsive and castration-resistant prostate cancer cells and primary tumors representing different stages of the disease, we found that galectin-1 (Gal-1) was the most abundantly expressed galectin in prostate cancer tissue and was markedly upregulated during disease progression. In contrast, all other galectins were expressed at lower levels: Gal-3, -4, -9, and -12 were downregulated during disease evolution, whereas expression of Gal-8 was unchanged. Given the prominent regulation of Gal-1 during prostate cancer progression and its predominant localization at the tumor-vascular interface, we analyzed the potential role of this endogenous lectin in prostate cancer angiogenesis. In human prostate cancer tissue arrays, Gal-1 expression correlated with the presence of blood vessels, particularly in advanced stages of the disease. Silencing Gal-1 in prostate cancer cells reduced tumor vascularization without altering expression of other angiogenesis-related genes. Collectively, our findings identify a dynamically regulated "galectin-specific signature" that accompanies disease evolution in prostate cancer, and they highlight a major role for Gal-1 as a tractable target for antiangiogenic therapy in advanced stages of the disease.

Oral Cavity Metastasis of Hepatocellular Carcinoma following Liver Transplantation.

Liver transplantation (LT) remains the only cure for hepatocellular carcinoma (HCC) in many cases. Over many years, most centers have applied the Milan criteria for selecting cirrhotic patients with HCC for LT. In a new era where several transplant groups are pushing the limits of transplanting HCC outside Milan criteria as an aggressive approach with promising results, we present interesting images of a patient that presented a unique and rare site of HCC metastasis after 36 months of liver transplantation.

[Prevalence of serrated adenomas of the colon and association with synchronic and metachronic neoplastic lesions]. / Prevalencia de adenomas serratos de colon y asociación con lesiones neoplásicas sincrónicas y metacrónicas.

OBJECTIVE: To determine the prevalence of serrated adenomas (SA), the frequency of high grade dysplasia (HGD) and adenocarcinoma in these polyps, and the association with synchronic (SNL) and metachronic neoplastic lesions (MNL). METHODS: Reports from patients undergoing colonoscopy and polypectomy from January 2003 to April 2010, were obtained from our electronic database. SA were reanalyzed by two pathologists and classified on the basis of Snover's diagnostic criteria. The prevalence of these polyps and the clinical and endoscopic features were determined. SNL were defined by adenomas, cancer or advanced neoplastic lesions (ANL) (> 1 cm, HGD and/or >75% of villous component) in the same colonoscopy. MNL were identified in patients who underwent surveillance colonoscopies. An univariate and multivariate analysis was performed, looking for independent predictors of HGD/ cancer, SNL and MNL in patients with SA. RESULTS: The prevalence of SA was 0.87%. The mean age was 60 years old and 50.5% of patients were women. Most of the polyps were sessile (67%), small (63%) and located in ceco-ascending colon (47%). We found HGD in 4.4% ofSA and no adenocarcinoma. SNL was found in 31% ofpatients: 46% adenomas, 40.5% ANL and 13.5% adenocarcinoma. MNL was found in 29% of patients: 25% SA, 31% adenomas, 44% ANL and 0% adenocarcinoma. Age over 60 years old was significantly associated with MNL [Odds ratio 3.7 (95% confidence interval 1.16-11.8)] and polyp's size higher than 1 cm with sessile SA histology [Odds ratio 8 (95% confidence interval 1.28-49.4)]. CONCLUSION: The prevalence of SA was low. We found an association with neoplastic lesions. Therefore, it is important to establish specific guidelines for the management of these polyps.

Paniculitis lipoatrófica y alteración del cromosoma 10 / Lipoatrophic panniculitis and alteration of chromosome 10

La paniculitis lipoatrófica (PL) es una enfermedad rara que afecta principalmente a mujeres y niños. Su forma de presentación consiste en múltiples placas eritematosas en las extremidades, que resuelven con atrofia subcutánea. Frecuentemente el cuadro se asocia con fiebre y trastornos autoinmunes. Presentamos una paciente de sexo femenino, de 8 años de edad, con síndrome febril de un mes de evolución asociado a atrofia y pigmentación en el dorso de las manos y piernas, edema semiduro simétrico del dorso de los pies pies y cara posterior del tercio distal de las piernas, nódulos en la cara posterior de las piernas, parestesias y limitación a la deambulación. Estudios complementarios: enzimas hepáticas, eritrosedimentación, proteína C reactiva, fibrinógeno y ferritina elevadas y FAN positivo; en la ecografía de partes blandas (pies, piernas y dorso de manos) presencia de múltiples imágenes pseudonodulares compatibles con focos de fibrosis; en la biopsia de piel (lesión nodular) hallazgos de paniculitis lobular; cariotipo 46XX, con anomalía estructural y deleción del brazo largo del cromosoma 10. Presentamos este caso, por tratarse de una patología infrecuente, con un sólo caso descripto en la literatura asociado a alteraciones del cromosoma 10, y por el desafío diagnóstico que ocasionó al plantel médico.

Lipoatrophic panniculitis is a rare disease affecting mostly women and children. It presents as multiple erythematous plaques on the extremities resolving with subcutaneous atrophy. Affected patients are often febrile and may have associated autoimmune phenomena. We report an 8-year-old girl, with 30-day history of fever, with atrophy and pigmentation on the back of the hand and legs, semi-hard symmetrical edema in the back of feet and distal posterior third of legs, and nodules on the back of the legs, paresthesia, and impaired deambulation. Complementary studies revealed elevated liver enzymes, fibrinogen, ferritin, VSG and CRP; positive ANA; multiple pseudonodular images compatible with focal areas of fibrosis in ultrasound of feet, limbs and back of the hands; skin biopsy (performed on a nodule) showed a lobular panniculitis; the chariotype was 46XX with structural anomaly and deletion of long arm of chromosome 10. We report this case because of its infrequent nature, with only one case reported in medical literature associated to chromosome 10 anomalies, and the diagnostic challenges that it represented to medical staff.

Accuracy in melanoma detection: a 10-year multicenter survey.

BACKGROUND: Early excision is the only strategy to reduce melanoma mortality, but unnecessary excision of benign lesions increases morbidity and healthcare costs. OBJECTIVE: To assess accuracy in melanoma detection based on number-needed-to-excise (NNE) values over a 10-year period. METHODS: Information was retrieved on all histopathologically confirmed cutaneous melanomas or melanocytic nevi that were excised between 1998 and 2007 at participating clinics. NNE values were calculated by dividing the total number of excised lesions by the number of melanomas. Analyses included changes in NNE over time, differences in NNE between specialized clinical settings (SCS) versus non-specialized clinical settings (NSCS), and patient factors influencing NNE. RESULTS: The participating clinics contributed a total of 300,215 cases, including 17,172 melanomas and 283,043 melanocytic nevi. The overall NNE values achieved in SCS and NSCS in the 10-year period were 8.7 and 29.4, respectively. The NNE improved over time in SCS (from 12.8 to 6.8), but appeared unchanged in NSCS. Most of the effect on NNE in SCS was due to a greater number of excised melanomas. Higher NNE values were observed in patients younger than 40 years and for lesions located on the trunk. LIMITATIONS: No data concerning the use of dermatoscopy and digital monitoring procedures were collected from the participating centers. CONCLUSION: Over the 10-year study period, accuracy in melanoma detection improved only in specialized clinics maybe because of a larger use of new diagnostic techniques such as dermatoscopy.

[Diffuse gastric cancer associated with Ménétrier's disease]. / Adenocarcinoma gástrico difuso asociado a enfermedad de Ménétrier.

BACKGROUND: Ménétrier's disease is a rare disease of the stomach generally described as hypertrophic gastropathy. Its etiology is unknown and its malignant potential is controversial. Only a few reports supporting its association with gastric cancer have been found. We present a case of gastric cancer associated with Ménétrier's disease. CASE REPORT: We present a 72 year-old-male with epigastric pain and early satiety during the last 5 months. He had been treated with proton pump inhibitors with unfavorable response and began with loss of weight and asthenia. An upper digestive endoscopy showed an erythematous nodular gastric mucosa, with enlarged folds. An abdominal CT scan demonstrated a circumferential parietal thickening of the gastric wall and adenopathies. A gastric macrobiopsy done by endoscopic mucosal resection evidenced a mucin infiltrating adenocarcinoma with invasion of the lamina propria. Subtotal gastrectomy was done. The histology showed a stomach with changes compatible with Ménétrier's disease and diffuse infiltration by a highly undifferentiated adenocarcinoma (plastic linitis). CONCLUSION: A patient with diffuse gastric adenocarcinoma and Ménétrier's disease is reported.

Carcinosarcoma / Sarcomatoid carcinoma

El carcinosarcoma es un tumor poco frecuente, bifásico, que ha sido comunicado en diferentes sitios del organismo. Está compuesto por un componente maligno epitelial íntimamente asociado con un componente epitelial sarcomatoide que puede ser homólogo y heterólogo. Existen carcinosarcomas cutáneos y extracutáneos. Los carcinosarcomas extracutáneos muestran un pronóstico pobre. Presentamos un paciente de 75 años, fototipo II, que consulta por presentar un tumor exofítico angiomatoide sangrante de 8 mm, de aspecto botriomicoide, de 2 meses de evolución en piel frontal derecha. Se confirma con biopsia y técnicas de inmunohistoquímica la existencia de 2 morfologías celulares típicas del carcinosarcoma. El tumor fue extirpado con un centímetro de margen de seguridad. El paciente, al año de su intervención, está libre de recurrencias y metástasis. El componente sarcomatoso del tumor es comprendido como una transformación metaplásica del componente carcinomatoso. Estos tumores son potencialmente agresivos.

Carcinosarcoma is an uncommon biphasic neoplasm that has been reported in diverseanatomical sites. This tumor is composed of two malignant epithelial components: onetypical and the other atypical, this one resembling mesenchymal tissue. Both are intimatelyassociated .The latter may be homologous or heterologous. When these tumors are locatedat extracutaneous sites, they are characteristically aggressive.We report a 75-year-old man who developed a solitary reddish bleeding nodule that quicklygrew in a two-months period. It resembled a pyogenic granuloma and was located on hisright frontal skin. Clinical, histologycal and immunohistochemical features were evaluated.The tumor was completely excised with a one-centimeter safety margin, and after a lapse ofone year he is free of local relapses or metastases.The sarcomatous component of the tumor is considered to be a metaplastic transformation ofthe carcinomatous component. These tumors are potentially aggressive if partially removed,thus complete excision is mandatory.

Características clínicas y dermatoscópicas del melanoma hipomelanótico / Clinical and dermoscopic features of hypomelanotic melanoma

Introducción. El melanoma hipomelanótico cutáneo (MHC) primario es una variante infrecuente de melanoma que se caracteriza por presentar escasez de pigmento a la inspección ocular. Las similitudes del MHC con diferentes entidades benignas o malignas dificultan y retardan el diagnóstico. La dermatoscopia es una técnica que permite visualizar estructuras como la red de pigmento y los vasos y optimiza el diagnóstico del MHC. Objetivo. Describir las características clínicas y dermatoscópicas del MHC. Diseño. Descriptivo y retrospectivo. Material y métodos. Muestra: fueron incluidos cuatro MHC confirmados por histopatología desde 1995 a 2010 en dos centros de la Argentina. Se utilizaron dermatoscopios de luz polarizada con y sin contacto. Los datos clínicos y sociodemográficos fueron obtenidos de las historias clínicas. Seanalizaron las patentes dermatoscópicas.Resultados. Rango de edad: 38-72 años. Sexo: 2 mujeres y 2 varones. Los fototipos cutáneos: I-II. Antecedentes de melanoma previo: 4 casos. Tiempo de evolución: de 3 a 12 meses. Características clínicas: placas eritematosas con escaso pigmento. Sospecha diagnóstica: MHC en los 4 casos. Histopatologías: 4 melanomas in situ, uno de ellos léntigo maligno. Dermatoscopia: red de pigmento (1/4), pigmentación marrón (3/4), crisálidas (1/4) y vasos puntiformes y lineales irregulares (4/4). Conclusiones. Los antecedentes de los pacientes y el entrenamiento en dermatoscopia del equipo interviniente optimizó el diagnóstico de MHC, lo que permitió la detección temprana y un tratamiento oportuno.

A colorectal mosaic pattern might be an endoscopic feature of collagenous colitis.

BACKGROUND AND AIMS: The endoscopic aspect of the colorectal mucosa in those patients with collagenous colitis is usually normal, or with non-specific changes. Until now it had never been related to a mucosal pattern of mosaic type. Our aim was to determine the diagnostic accuracy of the presence of mosaic pattern in the colorectal mucosa for collagenous colitis. METHODS: Patients who had undergone a colonoscopy with random biopsies performed in the diagnostic evaluation of chronic diarrhea between 2004 and 2008 were studied. We defined patients with chronic diarrhea and mosaic mucosal pattern as "cases", and patients with chronic diarrhea without mosaic pattern as "controls". The odds ratio (OR) of finding a collagenous colitis in view of a mosaic pattern in colon was determined; as well as sensitivity and specificity; positive and negative likelihood ratios (LR+, LR-), considering this finding as a diagnostic instrument for collagenous colitis. RESULTS: 252 patients who had undergone colonoscopy with biopsy due to chronic diarrhea were analyzed. In 6 patients, a mosaic pattern was identified in the colorectal mucosa. The histological diagnose of 36 of the 252 patients (14%) was microscopic colitis, 27 of which (11%) had collagenous colitis. The colonoscopy was found normal in 21 of these 27 patients; in 2 patients, congestion or petechiae was found in the rectum; and in 4 patients (15%), all women, a mosaic pattern was found in the rectosigmoid mucosa. The OR of this finding was 19.4 (CI 95% 3.9-95.4) for collagenous colitis. It had a sensitivity of 14.8% (CI 95% 6.8-20), a specificity of 99.1% (CI 95% 98.2-99.7), LR+ of 16.6 (CI 95% 3.7-76.4), and LR- of 0.86 (CI 95% 0.80-0.95) for a collagenous colitis. CONCLUSION: The mosaic pattern in the colorectal mucosa of patients studied due to chronic diarrhea could be a distinguishing feature of collagenous colitis.