Drainage of Cystic Mass on First Left Toe

Abstract

Cutaneous cysts are closed, sac-like, or encapsulated structures that may be filled with air, liquid, or semi-solid material, and are generally benign. Many types of cysts can occur in almost any place throughout the body and can form in all ages. They are seen as slow-growing and painless lumps underneath the skin. However, some cysts may be painful if they are particularly large. Treatment depends on several factors including the type of cyst, location, size, and the degree of discomfort caused. Large, symptomatic cysts can be removed surgically, while smaller, asymptomatic cysts can be drained or aspirated. Here, we present the case of a 12-year-old male with a pus-filled cystic mass on his first left toe and discuss surgical management and follow-up. 

Keywords

Infected cyst, cutaneous cyst, epidermal cyst.

Case Overview

Background

This patient underwent an incision and drainage of a small, pus-filled cystic mass located on the plantar aspect of his first left toe. This technique is a curative procedure that allowed the pus originally contained within the cyst to drain, thereby eliminating the cystic mass. The original plan was to create a Z-incision to relieve skin tension and to increase the exposure of the cystic mass. The surgeon was able to drain and expel most of the pus from the infected cyst through a single linear incision. By avoiding a bigger incision, the patient will recover more quickly with a better cosmetic outcome. 

Focused History of the Patient

An adolescent male was found to have a cystic mass on the plantar aspect of his first left toe. This mass caused the patient discomfort during walking or standing. The patient denied any history of fever, chills, or drainage from the mass.

Physical Exam

Physical examination is an important aspect of detecting cutaneous cysts. Preoperatively, the surgeon palpated what seemed like a solid nodular mass just beneath the skin on the plantar aspect of the first left toe. The overlying skin was intact without any signs of trauma, rashes, or lesions.

Imaging

Imaging is not usually warranted for the diagnosis of cutaneous cysts. However, an ultrasound can be performed to determine the extent and dimensions of the cyst. On all imaging modalities, cysts generally appear as well-circumscribed masses arising within, or just deep into the skin.¹

Natural History

Cutaneous cysts are closed, sac-like, or encapsulated structures that may be filled with air, liquid, or semi-solid material, and are generally benign. The diagnosis of cutaneous cysts is made based on the nature of the epithelial lining and the cyst content.² The most common cutaneous cysts such as milia and epidermoid cysts are lined by stratified squamous epithelium. Some cysts, including mucocele and digital myxoid cyst, are not lined by an epithelium. In this case, we are unsure of the epithelial lining since no biopsy was performed to determine this. The presence of pus in the cyst indicates an infectious etiology. The initial treatment of choice of a cyst, especially an infected cyst such as this case, would be an incision and drainage. There is a possibility that the cyst will recur if it has an epithelial lining. To prevent this recurrence, the capsule of the cyst must be removed. 

Options for Treatment

Minor cysts that present without irritating symptoms can be left untreated with watchful waiting. Steroid injections can be used initially to decrease inflammation in the cyst, making it less prevalent and painful. However, it is not indicated in this case because the cyst itself was already infected.

Rationale for Treatment

Surgical treatment is indicated when the cyst begins to cause discomfort, infection, inflammation, or for cosmetic purposes. In this case, the cyst required an incision and drainage because it was already infected. If left untreated, the infected cyst may become larger and cause increasing discomfort. Furthermore, an untreated infected cyst can infect the surrounding areas causing cellulitis or osteomyelitis. Infected cysts may even infect the bloodstream.

Special Considerations

There are no absolute contraindications to the incision and drainage of an infected cyst. Caution is advised in patients with bleeding disorders, taking anticoagulants, or with thrombocytopenia. Depending on the type of cyst, the capsule can be removed at a later time, which requires patient follow-up.

Discussion

This presentation of a cystic mass was unexpected, as the preoperative assessment had suggested a solid mass. The initial surgical plan was to simply remove and excise this seemingly solid mass. Upon discovering that the mass was cystic and pus-filled, the surgical plan changed to an incision and drainage. An incision and drainage technique constitutes the primary therapy for the management of cutaneous infected cysts. Most cutaneous abscesses are appropriate for incision and drainage when they are greater than 5 mm in diameter and are in an accessible location.³

Transient bacteremia can occur during an incision and drainage procedure. Therefore, patients may require preoperative treatment with antibiotics. Antibiotic treatment is usually recommended for patients with any of the following: single abscess ≥ 2 cm, multiple lesions, extensive surrounding cellulitis, associated immunosuppression, systemic signs of toxicity (e.g. fever > 100.5°F/38°C, hypotension, or sustained tachycardia), those with an indwelling medical device (e.g. prosthetic joint) or in patients who had an inadequate clinical response to incision and drainage alone.⁴ Healthy patients, such as in this case, who have small abscesses (e.g. < 2 cm) with no local signs of cellulitis or systemic signs of bacteremia can forego antibiotic therapy. Furthermore, subsequent treatment with antibiotics is not usually necessary after a successful incision and drainage procedure in a healthy patient.

The postsurgical care from a successful incision and drainage of a simple abscess consists of allowing the incision to openly drain the wound. This will allow the body’s host defenses to clear the infection without exposing the patient to the potential adverse effects of antibiotic therapy. As shown in the video, the wound was covered with a sterile, non-adherent dressing. Patients should expect some continued drainage from the packed wound. On subsequent visits for wound care, packing material should be removed to permit healing by secondary intention.³

Equipment

No special equipment was used.

Disclosures

Nothing to disclose.

Statement of Consent

The patient referred to in this video article has given their informed consent to be filmed and is aware that information and images will be published online.