8. Diagnostic assessment
What to write
8a – Diagnostic methods (e.g., physical examination, laboratory testing, imaging, questionnaires)
8b – Diagnostic challenges (e.g., financial, language, or cultural)
8c – Diagnostic reasoning including other diagnoses considered
8d – Prognostic characteristics (e.g., staging) where applicable
Explanation
Most case reports describe patients whose presentation is either a rare manifestation of an established disease or the first clue to a previously unknown disease. In either case, an accurate diagnosis is the essential element of a case report, and the author must provide a complete description of the diagnostic process. Whether a patient whose presentation is a rare manifestation of an established disease or the first clue to a previously unknown disease, the diagnostic assessments are essential. We recommend reporting relevant deidentified results of diagnostic evaluations with the dates they were performed. These could include laboratory results, radiographic and cardiographic images, and patient-reported outcome measurement surveys1. Include a brief explanation of the relevant results with reference ranges if necessary2. When trying to establish a cause and effect relationship between an exposure and a clinical event, document time course and dose of exposure to the onset of the clinical syndrome3 Important follow-up diagnostic assessments should be reported in the “Follow-up and Outcomes” section.
A case report should, if possible, cite literature references that support or challenge the main diagnostic hypotheses. Other diagnostic challenges such as obstacles to completing the evaluation may be important to mention. Likewise, discuss the evidence for the prognosis which may be affected by factors such as histological and genetic abnormalities, concomitant diagnoses, and therapeutic interventions used. These can be further elaborated in the discussion section.
Examples
8a—Diagnostic methods (e.g., PE, laboratory testing, imaging, questionnaires)
“Investigations were significant for a magnetic resonance imaging (MRI) study with and without contrast that revealed cerebral ischemic gliosis compatible with the patient’s age without acute intracranial pathology. There were no abnormalities noted along the course of either cranial seventh nerve. Her left STAB incision did not show evidence of thrombus, inflammation, or giant cells and hence was without evidence of temporal arteritis.”
From Branch facial nerve trauma after superficial temporal artery biopsy: a case report4.
8b—Diagnostic challenges (e.g., financial, language, or cultural)
“Delay of diagnosis resulted in a severe gradual deterioration in our patient. His initial clinical diagnosis of muscular dystrophy was further confirmed with diagnostic studies, according to the family, although we acknowledge that another muscle biopsy may be needed to exclude a diagnosis of muscular dystrophy (though we doubt that this was the actual diagnosis). As a result of the original diagnosis, however, our patient did not seek further evaluation for several years because he understood that there was no treatment for his condition. Decades later, further work-up with simple imaging techniques easily confirmed the etiology of his symptoms. Unfortunately, this delay in diagnosis resulted in the development of irreversible severe chronic muscle wasting. With such advanced atrophy and severe weakness, surgery will likely not provide significant functional benefit.
The differential diagnosis of bibrachial atrophy and syringomyelia is important. While we cannot definitively exclude that both the cervicothoracic syringomyelia and the bibrachial amyotrophy occurred as two separate entities, we doubt this…. We do not know why our patient’ s symptoms were stable for over 20 years. Although there was no history of any preceding head or neck trauma, perhaps the syrinx rapidly enlarged in the process of the disease. Without prior imaging, this is impossible to say with any certainty.”
From Chiari malformation type I with cervicothoracic syringomyelia masquerading as bibrachial amyotrophy: a case report5.
8c—Diagnostic reasoning including other diagnoses considered
“Differential diagnosis.
Taking carefully into account the previous in-depth history of both patients, a molecular analysis of the MEFV gene was decided. A rapid screening test of the entire coding sequence of MEFV gene, combined with targeted sequencing, revealed that both patients suffered from FMF as no other etiology had been identified thus far, whereas there was an appropriate exclusion of infectious, malignant, autoimmune, rheumatic, and liver and biliary diseases at their last submission. Actually, the mutational analysis revealed that the male patient carried the R202Q/R202Q homozygous alteration in exon 2 of the MEFV gene, whereas the female young patient was heterozygous for the M694V/0 conservative mutation in exon 10 and homozygous for the R202Q/R202Q mutation in exon 2.”
From Severe liver involvement in two patients with long-term history of fever: remember familial Mediterranean fever6.
8d—Prognostic characteristics (e.g., staging) where applicable
“Procalcitonin is a useful tool in the early diagnosis of sepsis, differentiating from other inflammatory syndrome. The high PCT level (10 ng/mL) in this case could suggest serious bacterial infection and sepsis and also predicts mortality and worse outcome.”
From Procalcitonin as a diagnostic and prognostic marker for sepsis caused by intestinal infection: a case report.7
Training
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