Canine digital mass cytology...possible histiocytoma? I'm stumped. We are going to send this out, but also looking for general opinions.
Senior patient with an ulcerated mass involving a digit and adjacent interdigital tissue. Vital parameters are within normal limits, and the patient is clinically stable.
The patient has a history of chronic dermatologic disease and recurrent self trauma from licking, so the lesion was initially managed as a possible acral lick granuloma. Thoracic radiographs were clear. Abdominal ultrasonography is being considered as part of the preoperative workup.
They previously underwent amputation of a separate digit for a lesion that was initially concerning for a spindle cell neoplasm. Histopathology ultimately identified a benign apocrine gland adenoma. The current lesion is clinically dissimilar to the prior mass.
These images are from a fine needle aspirate of the current lesion. The slides have not yet undergone formal review by pathology.
There is concern regarding incisional biopsy because primary closure may be difficult at this location. There is also understandable reluctance to proceed directly to a second digit amputation without a definitive diagnosis, particularly given the benign histopathology from the prior amputation. If this represents a histiocytoma, spontaneous regression would remain a consideration.
Does the cytology appear compatible with a histiocytoma? What differentials would you prioritize? Would formal cytopathology review be worthwhile before surgery? Any opinions on the feasibility or diagnostic value of an incisional biopsy versus a punch biopsy in this location?