Uncovering A Verrucous Carcinoma Following Delayed Healing Of A TMA

These authors investigate an unexpected finding of verrucous carcinoma in a 37-year-old patient with diabetes who had a transmetatarsal amputation secondary to chronic osteomyelitis.

A 37-year-old male presented with a past medical history of hypertension, diabetes and chronic ulceration to the right plantar forefoot, and previous partial first and fifth ray amputations of the right foot. The patient had known osteomyelitis of the right forefoot and went to the operating room for a transmetatarsal amputation (TMA).    

The second, third and fourth metatarsal shafts were resected and a percutaneous tendo-Achilles lengthening procedure was performed in order to give the patient increased dorsiflexion at the ankle joint. The excised tissue was also sent for pathologic analysis and the pathologists noted no abnormalities. The operation proceeded without incident.    

Subsequent follow-up visits at the clinic showed little improvement at the surgical site with wound dehiscence and ulceration. Radiographs taken within four weeks after surgery showed significant osseous hypertrophy and osseous regrowth at the areas of amputation.    

The patient had a revisional surgery at the TMA site approximately nine months later to close the residual ulceration. We excised the affected tissue on the plantar aspect of the foot and acanthotic skin on the dorsal margin of the stump, and sent the tissue to pathology for analysis. The external surface of the excision was entirely replaced by an exophytic lobular and verrucoid mass. Pathology ultimately identified the lesion as verrucous carcinoma. The verrucoid growth pattern extended into underlying subcutaneous tissue and lateral epidermal margins as well as focally to the deep margin of resection at the edges of the lesion. No vascular invasion was present.   

We referred the patient to an oncologist for further workup and continue to monitor his progress on a weekly basis, but there has been very little improvement. Most recently, approximately nine months after the revisional TMA, the patient developed an abscess and we performed subsequent incision and drainage in the operating room. It is possible that the patient will need to undergo a below-knee amputation in order to fully rectify the chronic ulceration and verrucous carcinoma of his foot.

Understanding The Diagnostic Challenges And Potential Gravity Of Verrucous Carcinoma In Chronic Wounds

Nobody identified the verrucoid lesion in this patient after his first transmetatarsal amputation even though biopsies of the soft tissue and bone excisions went for analysis.    

Since verrucous carcinoma lesions are more common in the midfoot region and the initial amputation was distal to the Lisfranc joint, it is entirely possible that the lesion was present from the beginning and simply was not resected until after the revisional surgery less than a year later. The physical appearance of the lesion was “quagmired” by chronic osteomyelitis and significant plantar ulceration, which lowered the suspicion of other concurrent disease processes.    

Verrucous carcinoma lesions typically follow a chronic course and are slow growing in nature. The confusing early presentation of this disease can often lead to a myriad of differential diagnoses that include benign lesions, actinomyces, verruca plantaris, pseudoepitheliomatous hyperplasia and plantar fibromatosis. The identification of verrucous carcinoma is further complicated by infection and the evolution of these focal lesions into deeply penetrating masses.    

There is no widely accepted treatment for verrucous carcinoma of the foot other than wide tissue excision at the surgical site. The disease structurally distorts adjacent tissue margins and one must aggressively remove the tissue to avoid further penetration. Even though surgeons have utilized topical chemotherapy, electrocautery and cryotherapy as therapeutic modalities, the recurrence rates of verrucous carcinoma remain extremely high in these cases.    

One should definitely consider verrucous carcinoma as a possible diagnosis in chronic wounds with lobular, exophytic masses. Although the potential for metastasis is extremely low, the consequences of the disease spreading can be devastating and can ultimately lead to amputation at the level of the knee among other complications.    

Mr. Khademi is a third-year student at the Dr. William M. Scholl College of Podiatric Medicine at Rosalind Franklin University of Medicine and Science in Chicago. He is the Research Coordinator for the Scholl Student Chapter of the American College of Foot and Ankle Surgeons (ACFAS).    

Mr. Holand is a third-year student at the Dr. William M. Scholl College of Podiatric Medicine at Rosalind Franklin University of Medicine and Science in Chicago. He is the Vice President of the ACFAS’ Scholl Student Chapter.    

Dr. Yorath is the Medical Director of the Rosalind Franklin University Health System and Associate Professor of Surgery at the Dr. William M. Scholl College of Podiatric Medicine at Rosalind Franklin University of Medicine and Science in Chicago. He is also the Residency Director of the Advocate Illinois Masonic Medical Center Podiatric Residency Program in Chicago.    

Dr. Wu is the Associate Dean of Research, a Professor of Surgery at the Dr. William M. Scholl College of Podiatric Medicine, and Professor of Stem Cell and Regenerative Medicine at the School of Graduate Medical Sciences at the Rosalind Franklin University of Medicine and Science in Chicago. She is also the Director of the Center for Lower Extremity Ambulatory Research (CLEAR) in Chicago.