TL;DR: A firm lump on your cat should be evaluated by a veterinarian within 48 to 72 hours to distinguish between benign growths and more serious conditions. Capturing a photo helps your veterinary team determine the urgency of the visit and prepare diagnostic tools.
What could a firm, marble-sized lump under my cat's skin be?
- Benign cysts and lipomas (fatty masses)
- Injection-site granulomas or abscesses
- Malignant tumors
- Professional diagnosis is necessary because many different types of masses feel similar to the touch.
Is finding a hard lump on my cat considered a veterinary emergency?
- The urgency level is generally Medium if your cat is eating, drinking, and acting normally.
- Schedule a veterinary appointment within 48 to 72 hours for a physical exam and possible diagnostics.
- Seek veterinary care sooner if the lump is rapidly growing, bleeding, or causing your cat obvious pain.
How does taking a photo of my cat's lump help the veterinary team?
- Allows the vet to assess the location and check for signs of inflammation or discharge.
- Establishes a baseline for the size of the mass to monitor changes.
- Helps the clinic determine how quickly your cat needs to be seen and which diagnostic tools, such as a fine needle aspirate, may be required upon arrival.
Clinical Context (Merck Veterinary Manual)
The presence of a hard, marble-sized lump under a cat's skin warrants investigation into several potential causes. Mammary tumors should be suspected upon detection of a mass during physical examination. Palpation of regional lymph nodes can help determine the extent of spread. Thoracic radiographs, preferably three views (a ventrodorsal and two laterals), should be taken to detect pulmonary metastases. Fine-needle aspirates may differentiate between inflammatory and neoplastic lesions but may lead to erroneous conclusions and delay of surgery. Definitive diagnosis is determined by histopathology, which is important for defining treatment and prognosis. Keratinized cutaneous cysts, malformations of the hair follicle, can also present as lumps. Cutaneous mast cell tumors can manifest as single, alopecic nodules, generally 2-3 cm in diameter. Surgical excision is the treatment of choice for mast cell tumors.
Chapter: Oncology, Dermatology
Source: The Merck Veterinary Manual, 11th Edition (Page 965)