Contributed by Hannah Kastenbaum, MD
The patient was a 75 year old female with a history of urothelial carcinoma treated initially by transurethral resection with intravesicular BCG and interferon-alpha. Her disease later progressed and she developed invasive tumor requiring radical cystectomy, hysterectomy, and renal resection, as well as adjunct chemoradiation. One year later she presented with left ankle pain and swelling. Plain radiograph of the ankle showed a lytic lesion in the proximal portion of the calcaneus (Figure 1). Magnetic resonance imaging demonstrated boney destruction (Figure 2).
Initially, the patient underwent fine needle aspiration biopsy followed by extended curettage with methylmethacrylate reconstruction. However, two months later, the patient had not received local radiotherapy and was still unable to ambulate. Radiographs demonstrated expansion of the lytic lesion around the cement packing and the patient underwent total calcanectomy (Figure 3).
The specimen consisted of a 9.0 x 5.5 x 5.5 cm calcaneus with adherent soft tissue including a 4 x 2 x 2 cm blue cement mass from the previous surgical procedure (Figure 4). Serial sections revealed an ill-defined soft tan-white mass, centrally necrotic, that extended from the posterior surface of the bone (Figure 5).
Hematoxylin and eosin- stained sections demonstrated nests of neoplastic cells with moderate eosinophilic cytoplasm and round-to-oval hyperchromatic nuclei arranged in pseudostratified layers and with central necrosis. Neoplastic cells invade into and through the boney table (Figures 6 and 7).
Immunohistochemical studies showed the neoplastic cells to stain positively for CK-7, p63, and thrombomodulin (Figures 8, 9, and 10). Stains for CK-20 and p16 were negative (Figure 11).