Rare constellation of unilateral superficial ulnar artery, variant common interosseous artery, and unilateral agenesis of palmaris longus.

Arterial pattern variations of the upper limb are not uncommon. During a routine dissection of an 85-year-old male cadaver, we observed a rare constellation of a unilateral superficial ulnar artery (SUA) arising from the distal brachial artery and a low common interosseous artery (CIA) arising from the radial artery (RA) combined with the unilateral agenesis of palmaris longus (PL) in the right upper limb. The combined presence of SUA, variant CIA, and absent PL in one upper limb has not yet been reported. Such arterial variations can complicate surgeries and interventions. SUA is prone to misinterpretation as a vein, accidental cannulation, and inadvertent intraarterial drug injections leading to gangrene and loss of limb. Meticulous care of the SUA is warranted during reconstructive free forearm flap surgeries involving RA. However, the unilateral absence of PL does not result in any significant functional loss. This rare constellation should assist clinicians in reconstructive and diagnostic procedures.