In simple words: This code describes a pilonidal cyst, a small, usually painless bump near the bottom of the spine, without an infection (abscess). It might look like a dimple. This is different from other conditions like a congenital (birth) dimple.

L05.91, in the ICD-10-CM classification, specifies a pilonidal cyst without an accompanying abscess.This condition is characterized by a cyst or sinus tract located in the sacrococcygeal region, typically near the cleft of the buttocks.The cyst may appear as a dimple and often involves hair follicles.It is crucial to distinguish this code from cases with an abscess (L05.92) or other related congenital conditions.The absence of an abscess is a key diagnostic criterion for using this code.

Example 1: A 25-year-old male presents with a small, painless dimple in the sacrococcygeal region.Physical examination reveals a pilonidal sinus without any signs of infection.The physician documents this as a pilonidal cyst without abscess, coding it as L05.91., A 30-year-old female reports a small, asymptomatic midline sacral dimple since birth.There is no inflammation, fluctuance, or drainage.After a thorough examination, the physician codes the finding as L05.91, recognizing it as a pilonidal cyst without an abscess and documenting the absence of infection., A 40-year-old patient is scheduled for a surgical excision of a pilonidal cyst. Preoperative assessment reveals no signs of an abscess. The procedure is performed, and the post-operative diagnosis confirms the absence of an abscess.The code L05.91 is assigned to reflect the preoperative and postoperative findings.

Complete history and physical examination including location, size, presence or absence of inflammation, discharge or other symptoms.Imaging studies (ultrasound or MRI) may be required to rule out complications or other diagnoses.

** This code is specific to pilonidal cysts without abscess formation.The presence of an abscess necessitates a different code (L05.92).