Occam\'s razor, the principle of parsimony, is frequently employed in medicine to derive a single diagnosis from a patient\'s myriad symptoms. Conversely, Hickam\'s dictum, which embraces the principle of plenitude by considering multiple diagnoses for a patient\'s presentation, is often underutilized or not as widely recognized as Occam\'s razor. The application of Hickam\'s dictum is particularly crucial when evaluating nonspecific symptoms such as fatigue, which can manifest in various diseases. This report describes the case of a 72-year-old man with a history of functional cure for hepatitis B who presented with chronic fatigue and hyponatremia. Initially, he was diagnosed with non-functional pituitary macroadenoma and panhypopituitarism. Two months following pituitary surgery, the onset of dyspepsia and the recurrence of fatigue revealed metastatic tumors in the liver, stomach, pancreas, left adrenal gland, and peri-pancreatic lymph nodes. A liver biopsy confirmed the diagnosis of hepatocellular carcinoma. This case highlights the importance of considering multiple, potentially co-existing conditions based on the patient\'s symptoms and risk factors to complete the thorough diagnoses. Additionally, it emphasizes the need to remain vigilant regarding the risk of liver cancer in patients with a history of chronic hepatitis B infection, irrespective of a functional cure.

We present the case of a patient with X-Linked Hypophosphatemia (XLH) and an inflammatory myofibroblastic tumor (IMT) of the bladder which prompted further investigation into the possible relationship between XLH and IMT i.e. a case of Occam\'s Razor or Hickam\'s Dictum?

Occam\'s razor-the principle of simplicity-has recently been attacked as a cultural bias without rational foundation. Increasingly, belief in pseudoscience and mysticism is growing. I argue that inclusion of Occam\'s razor is an essential factor that distinguishes science from superstition and pseudoscience. I also describe how the razor is embedded in Bayesian inference and argue that science is primarily the means to discover the simplest descriptions of our world.

Subacute combined degeneration (SCD) from vitamin B12 deficiency and spinal stenosis from degenerative changes may present similarly with weakness, sensory disturbances, and ataxia but require different treatments. This case report describes a 74-year-old male with suspected SCD who was discharged to an inpatient rehabilitation facility (IRF), did not improve with B12 supplementation, and later developed signs of myelopathy and diffuse joint pain. He ultimately was found to have severe cervical stenosis and pseudogout that were treated with a laminectomy and colchicine, respectively. Following surgical intervention, he returned to the IRF, where he had considerable functional improvement and was safely discharged home. This report shows the importance of recognizing the two conditions, their overlap, and the contrast between Occam\'s razor and Hickam\'s dictum.

The association between malignancies and autoimmunity had been well-established. The proposed pathophysiology and causality can be bidirectional. For example, a paraneoplastic syndrome can be triggered by an underlying malignancy or vice versa, where chronic inflammation of organs affected by autoimmunity can induce malignant transformation such as the case with inflammatory bowel disease and colorectal cancer or primary sclerosing cholangitis and hepatobiliary cancer. This report presents a case of autoimmune phenomena, namely, autoimmune hemolytic anemia, pernicious anemia, and Graves disease associated with newly diagnosed breast cancer. We also highlight the postulated pathophysiologic mechanisms in an attempt to answer the question of whether the occurrence of these autoimmune phenomena in our patient is a result of the law of parsimony (Occam\'s razor), where clinical variables are pathogenically related, or the counterargument, where random events and diseases can take place simultaneously (Hickam\'s dictum).

The basic principle of science is to always think of the simplest explanation for a condition. But in post graduate training, distinguishing a rare case from a common case is a dilemma for the naïve clinician. Often the eager and enthusiastic resident trainees are more prone to fall into this \"rare case phenomenon.\" Innumerable rare case reports in countless scientific journals may give the false impression to the budding trainee that uncommon cases are encountered every now and then. This article stresses on the importance of applying certain rules that can help in making the diagnostic process systematic and simpler. The chance of encountering rare cases are in fact rare and limited, wherreas in some circumstances, can diagnose life threatening conditions too.

A 77-year-old male presented with a progressively enlarging midline neck mass. On further investigation he was found to have synchronous thyroglossal duct cyst and extranodal mantle cell lymphoma (MCL) localized to the base of tongue. Both pathologies were managed simultaneously with a surgical approach and the patient remained in clinical remission at the time of publication without indication for systemic oncological treatment. Histology revealed primary extranodal nonblastoid MCL forming a base of tongue mass, with colonization of the thyroglossal duct cyst. Lymphoma was also found in the epithelium of a crypt-like tract traversing one of the tongue base tumor sections. This tract was anatomically and histologically consistent with documented descriptions of the foramen cecum. This case report illustrates a previously undescribed temporal, clinical, and histological association between a base of tongue MCL and symptomatic thyroglossal duct cyst. We provide evidence for a potential causal relationship for the presentation of the thyroglossal duct cyst as a result of oropharyngeal MCL, in the absence of clinical and histological evidence of disseminated disease, directly infiltrating from its tongue base origin to the infrahyoid neck region, potentially via an embryologic foramen cecum remnant. We also highlight the crucial role of the histopathologist in multidisciplinary clinicopathological discussion in demonstrating how fundamental embryological and microanatomical relationships can unite apparently separate diseases.

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In the realm of cellular-automata-based artificial life, configurations that self-reproduce employing signals are a more advanced form than those that reproduce holistically by simple fission. One might view those signals as a very rudimentary genetic code, since they guide the formation of the \"child\" from its \"parent.\" In principle, the signals could mutate to deliver a child better suited to reproduction in this artificial world. But even the simplest signal-based replicator discovered so far requires 58 specific CA transition rules that have been carefully hand-crafted to exactly meet the requirement of self-replication. Could such a system emerge without human design? This article considers how that might occur. Specifically, it demonstrates that the application of two heuristics can increase the probability that self-replication will emerge when needed transition rules are completed at random. The heuristics are using minimum total resources (parsimony) and maintaining structural continuity. Finally, the article suggests why parsimony is effective in catalyzing the emergence of self-replication.

Ventriculoperitoneal (VP) shunt surgery is probably the commonest surgical procedure in neurosurgery. Belying its technical simplicity is the myriad complications associated with it. Shunt malfunction is a common complication associated with this surgery, second only to shunt related infections, which may be associated with it. Sterile cerebrospinal fluid (CSF) eosinophilia (CE) has been reported with VP shunts, which may or may not be related to the dysfunction. Eosinophilia in the CSF has also been associated with a number of other conditions including parasitic infestations in the brain. This may be unrelated to the shunt surgery. We present a case of a child, operated earlier for hydrocephalus, who presented with sub-acute loss of vision and bilateral oculomotor paresis. CSF from a chamber tap revealed eosinophilia. The commonest presenting symptom of shunt malfunction is raised intracranial pressure. There are no reports in the literature of VP shunt malfunction presenting with bilateral oculomotor paresis and decreased visual acuity. The associated CE complicated the clinical picture, especially since the initial brain radiology was normal. We discuss the clinical differential diagnosis of this very interesting presentation, management dilemmas and outcome in this child. This rare clinical presentation was found to be the result of a shunt malfunction and not due to any rare parasitic infestation of the brain. Occam\'s razor dictates that the simplest explanation in a given situation is usually the most accurate, as is seen in this case.