The paracondylar process (PCP) is a wide-based, bony cone that stems from the exo-occipital bone beside the occipital condyle. In this case report, the morphology of a well-developed PCP, which we incidentally encountered in our previous craniovertebral region computed tomography (CT) study, and its relationship with the TVP of the atlas and the rectus capitis lateralis muscle were evaluated. Case Report: A well-developed PCP unilateral (left-sided) is noted in a 41-year-old male. The PCP is terminated by articulating with the transverse process (TVP) of the atlas medially from the mastoid process. The PCP widths were measured as 14, 9.8, and 10 mm at the base, middle, and apex, respectively. The base-to-apex length was 15.6 mm. The well-developed PCP is classified as a molar type. The rectus capitis lateralis muscle was atrophic on the left side of the PCP and normal on the right side. The area and circumference of the rectus capitis lateralis muscle were measured as 123.89 mm2, 50.9 mm, 91.66 mm2, and 40.9 mm on the right and left sides, respectively. In this rare case report, the well-developed PCP articulated with the TVP of the atlas and caused atrophy of the rectus capitis lateralis muscle, highlighting potential surgical challenges and the importance of recognizing this variation for clinical practice.
KEY WORDS: Craniovertebral region; Paracondylar process; Atlas; Junction; Variant anatomy.
ÇIMEN, K. & GÜL, E. Junction between well-developed paracondylar process and transverse process of the atlas: A very rare case report. Int. J. Morphol., 44(3):1020-1023, 2026.
