A Case Report on Variant Musculocutaneous and Ulnar Nerve Observed in the Right Upper Limb

During routine dissection of a 70 years old embalmed male cadaver in the department of Anatomy at K. J. Somaiya Medical College, Sion, Mumbai, INDIA, the unusual origin of musculocutaneous and ulnar nerve from median nerve were observed in the right upper limb. The variant median nerve crossed the brachial artery from behind. The thorough and meticulous dissection of axilla, arm, forearm and palm of both the upper limbs were done to note the course of the median nerve. The variation was unilateral and the left upper limb was normal. The arterial pattern in the arm was also normal. The photographs of the variations were taken for proper documentation. The median nerve and its roots are close to the axillary vein, which is used as the most cranial limit for axillary lymph node dissection, a procedure used in treating certain tumours, such as breast carcinoma and melanoma. The variations in the formation, course & distribution of median nerve are clinically important for surgeons, orthopaedicians and anaesthetist performing pain management therapies on the upper limb. These variations are compered with the earlier data & it is concluded that variations in the median nerve are a rule rather than exception. A lack of awareness of variations with different patterns might complicate surgical repair and may cause ineffective nerve blockade.