Cirugía monocular de 4 músculos extraoculares para la exotropía monocular de gran ángulo / Unilateral four muscle surgery for extra-large monocular exotropia

Introducción La exotropía recurrente es común después de cirugía para exotropía sensorial monocular constante de gran ángulo. La cirugía generalmente se limita al ojo afectado. El debilitamiento simultáneo de los músculos oblicuos ipsilaterales puede mejorar el efecto de la cirugía de los músculos rectos horizontales al disminuir las fuerzas de abducción. Presentamos los resultados de la cirugía simultánea de debilitamiento de los músculos oblicuos combinados con cirugía del músculo recto horizontal ipsilateral con exotropía monocular constante superior a 35 dioptrías prismáticas (DP). Métodos Serie retrospectiva en casos de retroinserción unilateral del recto lateral combinada con resección del recto medial, y debilitamiento simultáneo de ambos músculos oblicuos ipsilaterales. La medida de resultado fue la alineación ocular en la posición primaria. Resultados Se incluyeron 12 ojos de 12 pacientes. La exotropía preoperatoria mejoró de 57,9±15,1DP (rango 35-80; mediana 60) a 3,3±5,5 (rango 0-16; mediana 0) postoperatoriamente (p<0,005). Dos (66%) pacientes con desviación vertical preexistente tuvieron una resolución de su desalineación vertical postoperatoriamente. En el último seguimiento postoperatorio, el 92% de los pacientes tenían una exodesviación de 10DP o menos y 7 (58%) midieron ortotropía. La abducción postoperatoria midió −0,6±1(0 a −3) y la aducción −0,4±0,7 (0 a −2). Conclusión El debilitamiento de los músculos oblicuos puede mejorar el efecto de la cirugía de los músculos rectos horizontales al disminuir las fuerzas de abducción en casos de exotropía monocular de gran ángulo. Como ventaja adicional, la cirugía del músculo oblicuo se puede utilizar simultáneamente para abordar las desviaciones verticales asociadas (AU)

Introduction Recurrent exotropia is common following surgery for monocular large angle constant sensory exotropia. Surgery is usually limited to operations on the affected eye. Simultaneous oblique weakening surgery may enhance the effect of the horizontal rectus muscles surgery by decreasing the abducting forces. We report the results of simultaneous oblique muscle weakening procedures combined with ipsilateral horizontal rectus muscle surgery constant monocular exotropia greater than 35 prism diopters (PD). Methods Retrospective case series of patients who underwent unilateral lateral rectus recession combined with medial rectus muscle resection and simultaneous weakening of both ipsilateral oblique muscles. Primary outcome measure was ocular alignment in primary position. Results Twelve eyes of 12 patients were included. The mean preoperative exotropia improved from 57.9±15.1 (range 35–80; median 60PD) to 3.3±5.5 (range 0–16; median 0PD) postoperatively (p<0.005). Two (66%) patients with a pre-existing vertical deviation had resolution of their vertical misalignment postoperatively. At the last postoperative follow up 92% of the patients had an exodeviation of 10PD or less (range 0–16PD median 0PD), and 7 (58%) measured near and distance orthotropia. Postoperative abduction measured −0.6±1 (0 to −3) and adduction −0.4±0.7 (0 to −2). Conclusion Weakening the ipsilateral oblique muscles may enhance the effect of the horizontal rectus muscles surgery by decreasing the abducting vectorial forces when operating for a large angle monocular exotropia. As an additional potential advantage, oblique muscle surgery may be used simultaneously to address associated vertical deviations (AU)

Unilateral four muscle surgery for extra-large monocular exotropia.

INTRODUCTION: Recurrent exotropia is common following surgery for monocular large angle constant sensory exotropia. Surgery is usually limited to operations on the affected eye. Simultaneous oblique weakening surgery may enhance the effect of the horizontal rectus muscles surgery by decreasing the abducting forces. We report the results of simultaneous oblique muscle weakening procedures combined with ipsilateral horizontal rectus muscle surgery constant monocular exotropia greater than 35 prism diopters (PD). METHODS: Retrospective case series of patients who underwent unilateral lateral rectus recession combined with medial rectus muscle resection and simultaneous weakening of both ipsilateral oblique muscles. Primary outcome measure was ocular alignment in primary position. RESULTS: Twelve eyes of 12 patients were included. The mean preoperative exotropia improved from 57.9 ±â€¯15.1 (range 35-80; median 60 PD) to 3.3 ±â€¯5.5 (range 0-16; median 0 PD) postoperatively (p < 0.005). Two of 3 patients with a pre-existing vertical deviation had resolution of their vertical misalignment postoperatively. At the last postoperative follow up 92% of the patients had an exodeviation of 10 PD or less (range 0-16 PD median 0 PD), and 7 (58%) measured near and distance orthotropia. Postoperative abduction measured -0.6 ±â€¯1 (0 to -3) and adduction -0.4 ±â€¯0.7 (0 to -2). CONCLUSION: Weakening the ipsilateral oblique muscles may enhance the effect of the horizontal rectus muscles surgery by decreasing the abducting vectorial forces when operating for a large angle monocular exotropia. As an additional potential advantage, oblique muscle surgery may be used simultaneously to address associated vertical deviations.

Carrier-envelope-phase and helicity control of electron vortices and spirals in photodetachment.

Formation of electron vortices and spirals in photodetachment from the H- anion driven by isolated ultrashort laser pulses of circular polarization or by pairs of such pulses (of either co-rotating or counter-rotating polarizations) are analyzed under the scope of the strong-field approximation. It is demonstrated that the carrier-envelope phase (CEP) and helicity of each individual pulse can be used to actively manipulate and control the vortical and spiral patterns in the probability amplitude of photodetachment. Specifically, we show that the vortical patterns can be rotated in momentum space by the CEP of the driving pulse (or, of two identical pulses); thus, offering a tool of pulse characterization. For co-rotating pulses of arbitrary CEPs, a novel type of structured vortices is discovered. Also, we demonstrate that the momentum spirals are formed when photodetachment is driven by two pulses of time-reversal symmetry, which is accompanied by absolute disappearance of vortical structures. Hence, we attribute the spiral formation to annihilation of vortices with antivortices, which are generated by time-reversed pulses comprising the train. Finally, the CEP and helicity control of spiral structures is demonstrated, leading to their rotation in momentum space.

Characteristics of a Diverse Cohort of Stroke Patients with SARS-CoV-2 and Outcome by Sex.

BACKGROUND AND PURPOSE: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection is associated with stroke. The role of sex on stroke outcome has not been investigated. To objective of this paper is to describe the characteristics of a diverse cohort of acute stroke patients with COVID-19 disease and determine the role of sex on outcome. METHODS: This is a retrospective study of patients with acute stroke and SARS-CoV-2 infection admitted between March 15 to May 15, 2020 to one of the six participating comprehensive stroke centers. Baseline characteristics, stroke subtype, workup, treatment and outcome are presented as total number and percentage or median and interquartile range. Outcome at discharge was determined by the modified Rankin Scale Score (mRS). Variables and outcomes were compared for males and females using univariate and multivariate analysis. RESULTS: The study included 83 patients, 47% of which were Black, 28% Hispanics/Latinos, and 16% whites. Median age was 64 years. Approximately 89% had at least one preexisting vascular risk factor (VRF). The most common complications were respiratory failure (59%) and septic shock (34%). Compared with females, a higher proportion of males experienced severe SARS-CoV-2 symptoms requiring ICU hospitalization (73% vs. 49%; p = 0.04). When divided by stroke subtype, there were 77% ischemic, 19% intracerebral hemorrhage and 3% subarachnoid hemorrhage. The most common ischemic stroke etiologies were cryptogenic (39%) and cardioembolic (27%). Compared with females, males had higher mortality (38% vs. 13%; p = 0.02) and were less likely to be discharged home (12% vs. 33%; p = 0.04). After adjustment for age, race/ethnicity, and number of VRFs, mRS was higher in males than in females (OR = 1.47, 95% CI = 1.03-2.09). CONCLUSION: In this cohort of SARS-CoV-2 stroke patients, most had clinical evidence of coronavirus infection on admission and preexisting VRFs. Severe in-hospital complications and worse outcomes after ischemic strokes were higher in males, than females.

Structural and functional motor cortex asymmetry in unilateral lower limb amputation with phantom limb pain.

OBJECTIVE: The role of motor cortex reorganization in the development and maintenance of phantom limb pain (PLP) is still unclear. This study aims to evaluate neurophysiological and structural motor cortex asymmetry in patients with PLP and its relationship with pain intensity. METHODS: Cross-sectional analysis of an ongoing randomized-controlled trial. We evaluated the motor cortex asymmetry through two techniques: i) changes in cortical excitability indexed by transcranial magnetic stimulation (motor evoked potential, paired-pulse paradigms and cortical mapping), and ii) voxel-wise grey matter asymmetry analysis by brain magnetic resonance imaging. RESULTS: We included 62 unilateral traumatic lower limb amputees with a mean PLP of 5.9 (SD = 1.79). We found, in the affected hemisphere, an anterior shift of the hand area center of gravity (23 mm, 95% CI 6 to 38, p = 0.005) and a disorganized and widespread representation. Regarding voxel-wise grey matter asymmetry analysis, data from 21 participants show a loss of grey matter volume in the motor area of the affected hemisphere. This asymmetry seems negatively associated with time since amputation. For TMS data, only the ICF ratio is negatively correlated with PLP intensity (r = -0.25, p = 0.04). CONCLUSION: There is an asymmetrical reorganization of the motor cortex in patients with PLP, characterized by a disorganized, widespread, and shifted hand cortical representation and a loss in grey matter volume in the affected hemisphere. This reorganization seems to reduce across time since amputation. However, it is not associated with pain intensity. SIGNIFICANCE: These findings are significant to understand the role of the motor cortex reorganization in patients with PLP, showing that the pain intensity may be related with other neurophysiological factors, not just cortical reorganization.

Cortical plasticity in phantom limb pain: A fMRI study on the neural correlates of behavioral clinical manifestations.

The neural mechanism of phantom limb pain (PLP) is related to the intense brain reorganization process implicating plasticity after deafferentation mostly in sensorimotor system. There is a limited understanding of the association between the sensorimotor system and PLP. We used a novel task-based functional magnetic resonance imaging (fMRI) approach to (1) assess neural activation within a-priori selected regions-of-interested (motor cortex [M1], somatosensory cortex [S1], and visual cortex [V1]), (2) quantify the cortical representation shift in the affected M1, and (3) correlate these changes with baseline clinical characteristics. In a sample of 18 participants, we found a significantly increased activity in M1 and S1 as well as a shift in motor cortex representation that was not related to PLP intensity. In an exploratory analyses (not corrected for multiple comparisons), they were directly correlated with time since amputation; and there was an association between increased activity in M1 with a lack of itching sensation and V1 activation was negatively correlated with PLP. Longer periods of amputation lead to compensatory changes in sensory-motor areas; and itching seems to be a protective marker for less signal changes. We confirmed that PLP intensity is not associated with signal changes in M1 and S1 but in V1.

Anterior segment ischemia: etiology, assessment, and management.

Anterior segment ischemia (ASI) is a potentially serious but rare complication of strabismus surgery. Among several risk factors, ASI occurs after strabismus surgery because of the nature of the anterior segment circulation. Disinsertion of rectus muscles leads to a decrease in the blood supply to the various anterior segment structures. We report a series of retrospective and prospective studies performed by our group focused on determining the risk of anterior segment ischemia following strabismus surgery, diagnosis, and modifications to surgical techniques to minimize the impact on anterior segment circulation. We found a significant decrease in postoperative anterior segment blood flow when operating vertical rectus muscles. Plication procedures preserve anterior segment circulation, and modifications to the technique allow the performance of adjustable sutures. Small adjustable selective procedures that spare the ciliary vessels have been demonstrated to be effective in patients with vertical and torsional diplopia. Ciliary sparing augmented adjustable transposition surgery decreases the risk of anterior segment ischemia while allowing management of potential post-operative alignment complications. Finally, ocular coherence tomography angiography is a valuable quantitative and qualitative technique to evaluate anterior segment ischemia. Strabismus surgeons should be aware of the risks of anterior segment ischemia when operating vertical rectus muscles. Modifications to standard surgical techniques allow surgeons to perform complex strabismus surgery in patients at risk for anterior segment ischemia.

Numerical modeling of fiber specklegram sensors by using finite element method (FEM).

Although experimental advances in the implementation and characterization of fiber speckle sensor have been reported, a suitable model to interpret the speckle-pattern variation under perturbation is desirable but very challenging to be developed due to the various factors influencing the speckle pattern. In this work, a new methodology based on the finite element method (FEM) for modeling and optimizing fiber specklegram sensors (FSSs) is proposed. The numerical method allows computational visualization and quantification, in near field, of changes of a step multi-mode fiber (SMMF) specklegram, due to the application of a uniformly distributed force line (UDFL). In turn, the local modifications of the fiber speckle produce changes in the optical power captured by a step single-mode fiber (SSMF) located just at the output end of the SMMF, causing a filtering effect that explains the operation of the FSSs. For each external force, the stress distribution and the propagations modes supported by the SMMF are calculated numerically by means of FEM. Then, those modes are vectorially superposed to reconstruct each perturbed fiber specklegram. Finally, the performance of the sensing mechanism is evaluated for different radius of the filtering SSMF and force-gauges, what evidences design criteria for these kinds of measuring systems. Results are in agreement with those theoretical and experimental ones previously reported.

In vitro antiviral activity against rotavirus and astrovirus infection exerted by substances obtained from Achyrocline bogotensis (Kunth) DC. (Compositae).

BACKGROUND: Achyrocline bogotensis has been traditionally used to treat infections of skin, respiratory, tract urinary and other infections, but not to treat viral gastrointestinal disease. In this study, this Colombian native medicinal plant was investigated by its in vitro anti-rotavirus and anti-astrovirus activity. METHODS: Several extracts and fractions phytochemically obtained from A. bogotensis were evaluated initially for their cell toxicity on MA104 and Caco2 cells and then for their anti-rotavirus (RRV) and anti-astrovirus (Yuc8) activity following three strategies: pre-treatment of cells (blocking effect), direct viral activity (virucidal effect) and post-treatment of infected cells (reduction of viral yield post-infection). In addition qualitative chemical studies were developed for the active compounds. RESULTS: Non-toxic concentrations of a fraction obtained exhibited antiviral activity against both viruses characterized by a virucidal effect and by the reduction of the infectious particles produced post-infection. Steroids, sterols, terpenes, phenols, flavonoids and sesquiterpenlactones were identified qualitatively in the active fraction. CONCLUSIONS: A. bogotensis contains substances with in vitro antiviral activity against rotavirus and astrovirus. This study confirms their anti-microbial properties and describes by the first time its antiviral activity in vitro.

Analysis of gold nanoparticles as carriers for different molecular dye type photosensitizers in Photodynamic Therapy applied to carcinomas.

The effect of gold nanoparticles on the depth of photodynamic treatment for different types of photosensitizers with significant potential for their application in oncology is studied by means of a predictive model. Results show differences of up to 18 % when nanoparticles are used as carriers for Cyanine based photosensitizers in a carcinoma. Therefore these results could be useful to rule out the administration of this means of delivery for certain molecular dye type photosensitizers when Photodynamic Therapy is applied to carcinomas with a given structure.

Analysis of Low Intensity Laser Therapy as adjuvant to Photodynamic Therapy in Nonmelanoma Skin Cancer.

The combination of Low Intensity Laser Therapy and Photodynamic Therapy constitutes a minimal invasive and highly selective alternative for the treatment of skin tumors. Photodynamic effectiveness, specially the absence of recurrence, highly depends on the type of tumor, as well as on several parameters such as those related with the optical source. Therefore it is important to have predictive tools to provide an appropriate treatment planning. This work proposes the use of a complex predictive model that includes a three-dimensional meshing of the considered tumor geometry and the optical propagation therein by a three-dimensional Monte Carlo method. The proposed tool is applied to three different types of skin tumors, squamous cell carcinoma, nodular and infiltrative basal cell carcinomas. The estimated volume of treatment, depending on the tumor type and source parameters, allows an appropriate treatment planning in order to avoid undesirable tumor recurrence.

Simultaneous surgery for corneal edema and aphakia: DSEK and placement of a retropupillary iris claw lens.

PURPOSE: The aim was to report the surgical outcomes of simultaneous Descemet stripping endothelial keratoplasty (DSEK) with a retropupillary fixated iris claw lens in patients with aphakic corneal edema without capsular support. METHODS: The clinical records of aphakic patients with corneal edema and no capsular support who underwent a combined DSEK and implantation of a retropupillary fixated iris claw lens (Artisan) were evaluated. Presurgical and postsurgical best-corrected visual acuity, postsurgical refraction, and endothelial cell count were analyzed at the first and sixth months after the surgery and were imaged with anterior segment ultrasound biomicroscopy. RESULTS: A total of 9 eyes from 7 females and 2 males were analyzed. The average age was 72.1 years. The mean duration of the postoperative follow-up was 7.7 months. All the patients achieved corrected visual acuities over 0.60 logarithm of the minimum angle of resolution. There was no significant variation in the endothelial count between the first and sixth months. Astigmatism >1 D was induced in all the patients, with 7 patients having against the rule, and 2 patients having oblique astigmatism. CONCLUSIONS: DSEK combined with a retropupillary fixated iris claw lens was shown to be a safe surgical technique in patients with aphakia without capsular support and corneal swelling. This surgery resulted in stable endothelial cell counts during the first 6 months after the surgery and an improvement in visual acuity.

Spontaneous autoimmune gastritis and hypochlorhydria are manifest in the ileitis-prone SAMP1/YitFcs mice.

SAMP1/YitFcs mice serve as a model of Crohn's disease, and we have used them to assess gastritis. Gastritis was compared in SAMP1/YitFcs, AKR, and C57BL/6 mice by histology, immunohistochemistry, and flow cytometry. Gastric acid secretion was measured in ligated stomachs, while anti-parietal cell antibodies were assayed by immunofluorescence and enzyme-linked immunosorbent spot assay. SAMP1/YitFcs mice display a corpus-dominant, chronic gastritis with multifocal aggregates of mononuclear cells consisting of T and B lymphocytes. Relatively few aggregates were observed elsewhere in the stomach. The infiltrates in the oxyntic mucosa were associated with the loss of parietal cell mass. AKR mice, the founder strain of the SAMP1/YitFcs, also have gastritis, although they do not develop ileitis. Genetic studies using SAMP1/YitFcs-C57BL/6 congenic mice showed that the genetic regions regulating ileitis had comparable effects on gastritis. The majority of the cells in the aggregates expressed the T cell marker CD3 or the B cell marker B220. Adoptive transfer of SAMP1/YitFcs CD4(+) T helper cells, with or without B cells, into immunodeficient recipients induced a pangastritis and duodenitis. SAMP1/YitFcs and AKR mice manifest hypochlorhydria and anti-parietal cell antibodies. These data suggest that common genetic factors controlling gastroenteric disease in SAMP1/YitFcs mice regulate distinct pathogenic mechanisms causing inflammation in separate sites within the digestive tract.

Henipavirus: a review of laboratory animal pathology.

The genus Henipavirus contains two members-Hendra virus (HeV) and Nipah virus (NiV)-and each can cause fatal disease in humans and animals. HeV and Niv are currently classified as biosafety level 4, and NiV is classified as a category C priority pathogen. The aim of this article is to discuss the pathology of laboratory animal models of henipavirus infection and to assess their suitability as animal models for the development and testing of human therapeutics and vaccines. There has been considerable progress in the development of animal models for henipavirus disease. Suitable animal models include the golden hamster, ferrets, cats, and pigs, which develop disease resembling that observed in humans. Guinea pigs are a less reliable model for henipavirus disease, but they do develop henipavirus-induced encephalitis. Because human efficacy studies with henipaviruses are not permitted, animal studies are critical for the development of antiviral therapeutics and vaccines. Current research indicates that passive immunotherapy using monoclonal antibodies is protective of ferrets against NiV infection and that passive immunotherapy using NiV antibodies protects hamsters from HeV. Recombinant vaccines have been used to protect cats and pigs against NiV infection. Ribavirin and 6-aza-uridine were able to delay but not prevent NiV-induced mortality in hamsters. Further research is needed to develop a model and therapy for late-onset henipavirus encephalitis.

An in situ hybridization and immunohistochemical study of cytauxzoonosis in domestic cats.

Cytauxzoonosis, caused by the protozoan parasite, Cytauxzoon felis, is a tick-borne disease of domestic cats causing high mortality. The reservoir is wild felids. In this study, 7 archived cases of the disease were examined through in situ hybridization for localization of the parasite and by immunohistochemistry for various cell markers to characterize infected cells. The riboprobe used was specific for the 16S-like rRNA subunit of Babesia microti, which shares 91% identity with the same gene for C. felis. In situ hybridization highlighted the presence of the organism in several tissues, most prominently lung and spleen, and, in general, there were 2 to 10 times more infected cells seen with in situ hybridization than with HE. Parasite-laden cells were usually found within vessels. These cells were often tightly packed and frequently formed parasitic thrombi. Immunohistochemistry with an antilysozyme antibody confirmed the macrophage origin of the infected cells. Using an antibody specific for calprotectin (Mac387), parasitized cells were markedly devoid of this protein, which may explain the lack of diapedesis and vascular crowding of parasitized cells, providing more circulating parasites for the tick vector. Immunohistochemical labeling for 2 proliferation markers, proliferating cell nuclear antigen (PCNA) and p53, indicated that parasitized cells have a heightened replicative ability, which is probably an additional parasite-driven modification to facilitate survival and transmission.

Localization of fibropapilloma-associated turtle herpesvirus in green turtles (Chelonia mydas) by in-situ hybridization.

Fibropapilloma-associated turtle herpesvirus (FPTHV) is the presumed aetiological agent of sea turtle fibropapillomatosis (FP). Intralesional DNA and RNA of the virus have been detected by polymerase chain reaction (PCR) and reverse transcriptase-PCR (RT-PCR), respectively, but the exact location and distribution of the virus within the tumours have not been addressed. In this study, in-situ hybridization (ISH) was used to investigate viral transcriptional activity and localization of FPTHV. Twenty-five tumours were obtained from the skin or conjunctiva of 105 green turtles (Chelonia mydas) examined on two islands in Puerto Rico (Culebra and Culebrita). These lesions comprised 19 fibropapillomas and six fibromas. FPTHV mRNA transcripts were detected by ISH in three fibropapillomas, with positive reactions confined to the nuclei of clusters of epithelial cells. Viral DNA was detected by riboprobe ISH combined with denaturation in 14 tumours, including both fibropapillomas and fibromas. Signals were confined to the nuclei of acanthotic epithelial cells and were not seen in the subepithelial fibrous areas of the tumours. These results suggest that FPTHV is present in epithelial cells and transcriptionally active in fibropapillomas.

Histopathologic and immunohistochemical characterization of Nipah virus infection in the guinea pig.

Mortality rate in humans infected with Nipah virus (NiV) has been reported as high as 92%. Humans infected with NiV show a widespread multisystemic vasculitis with most severe clinical and pathologic manifestations in the brain, lungs, and spleen. The purpose of this study was to study pathologic and immunohistochemical findings in guinea pigs infected with NiV. Of 28 animals inoculated intraperitoneally, only 2 survived the infection, and most died between 4 and 8 days postinoculation (dpi). Viral antigen with minimal pathologic changes was first detected 2 dpi in lymph nodes and spleen. More severe changes were noted in these organs 4-8 dpi, where pathologic damage had a vasocentric distribution and viral antigen was abundant in vascular endothelium, tunica media, adventitia, as well as in macrophages lining sinuses. The urinary bladder, uterus, and ovaries were also affected with necrosis and acute inflammation. In these organs, immunohistochemical positive staining was intense in blood vessels, epithelial cells, and ovarian follicles. Approximately 50% of the animals that died or were euthanized in extremis had evidence of viral antigen and histopathologic changes in brain, especially involving meninges and ependymal cells, with lesser changes in the neural parenchyma. A unifying feature of the damage for all affected tissues was necrosis and inflammation of the vasculature, chiefly in arterioles, capillaries, and venules. Inoculation of guinea pigs intraperitoneally with NiV produces a disease with considerable resemblance to the disease in humans, but with reduced pulmonary involvement and marked infection of urinary bladder and the female reproductive tract.

[Occult breast cancer: Report of two cases]. / Cancer de mama oculto: dos casos clínicos analizados según el concepto actual.

Occult breast cancer is expressed as a metastatic axillary lymph node without clinical or imaging evidence of a primary tumor in the breast. The old concept involved non palpable tumors. Its incidence is low, representing only 0.3 to 1% of all breast cancer cases. The search for the primary tumors is performed with mammography, whose sensitivity is low, ranging from 0 to 56%. Several studies have shown a higher sensitivity of magnetic resonance imaging, ranging from 85 to 100%, to detect occult lesions. The treatment of isolated axillary metastases of breast cancer is controversial. An axillary dissection is recommended. If there is a suspicious image, a radiosurgical or stereotaxic biopsy should be done. However, in patients without radiological lesions in the breast, the tendency is not to perform a radical mastectomy as previously recommended, since the primary tumor will not be found in the surgical specimen in two thirds of cases. A superior and external quadrantectomy or exclusive radiotherapy should suffice. An expecting behavior is not recommended as a therapeutic alternative. Treatment should be complemented with hormonal therapy or chemotherapy. The literature suggests that prognosis is better than stage II, with a ten years survival ranging from 50 to 71%. We report two patients with a well defined occult breast cancer and based on them, a review of the subject is attempted. Considering its prognosis, physicians should be aware of this uncommon and difficult to diagnose disease.

Cancer de mama oculto: dos casos clínicos analizados según el concepto actual / Occult breast cancer: Report of two cases

Occult breast cancer is expressed as a metastatic axillary lymph node without clinical or imaging evidence of a primary tumor in the breast. The old concept involved non palpable tumors. Its incidence is low, representing only 0.3 to 1 percent of all breast cancer cases. The search for the primary tumors is performed with mammography, whose sensitivity is low, ranging from 0 to 56 percent. Several studies have shown a higher sensitivity of magnetic resonance imaging, ranging from 85 to 100 percent, to detect occult lesions. The treatment of isolated axillary metastases of breast cancer is controversial. An axillary dissection is recommended. If there is a suspicious image, a radiosurgical or stereotaxic biopsy should be done. However, in patients without radiological lesions in the breast, the tendency is not to perform a radical mastectomy as previously recommended, since the primary tumor will not be found in the surgical specimen in two thirds of cases. A superior and external quadrantectomy or exclusive radiotherapy should suffice. An expecting behavior is not recommended as a therapeutic alternative. Treatment should be complemented with hormonal therapy or chemotherapy. The literature suggests that prognosis is better than stage II, with a ten years survival ranging from 50 to 71 percent. We report two patients with a well defined occult breast cancer and based on them, a review of the subject is attempted. Considering its prognosis, physicians should be aware of this uncommon and difficult to diagnose disease.