Lessons in clinical reasoning - pitfalls, myths, and pearls: a case of tarsal tunnel syndrome caused by an intraneural ganglion cyst.

Through integrated commentary by a case discussant and reflection by an orthopedician, this case highlights the significance of the availability heuristic, confirmation bias, and anchoring bias in a case of rare disease. Despite diagnostic delays, a medically knowledgeable patient's involvement in their own care lead to a more positive outcome. A fish-bone diagram is provided to visually demonstrate the major factors that contributed to the diagnostic delay. Finally, this case provides clinical teaching points in addition to a pitfall, myth, and pearl related to availability heuristic and the sunk cost fallacy.