Multicentric giant cell tumor involving the same foot: A case report and review of literature

Multicentric giant cell tumour (GCT) is extremely rare; no case has been previously reported where two lesions occurred in the same foot at different sites. We report a case involving the calcaneus and subsequently the 3 rd toe of the same foot and review the reported literature. In established cases of multicentricity, the histopathology has to be properly reviewed and the patient has to be followed up for a longer time with serial whole body assessment to pick up any subsquent lesions. The treatment of the local disease does not differ from a standard GCT.

G iant cell tumor (GCT) of bone is a benign aggressive calcaneum and extending into the tuberosity with cortical tumor with features of frequent local recurrences breach of the medial and lateral walls. All other bones in and potential for metastasis and malignant the foot were apparently normal. The chest radiograph was transformation. 1 Nearly 50% of the cases occur in the normal. Open biopsy showed histological characteristics region of the knee and other frequent sites include the distal consistent with GCT [ Figure 3]. The calcaneum was radius, proximal humerus and fibula and the pelvic bones. 2, 3 approached through a lateral incision; curettage using Involvement of the small bones of the foot and hand by powered burrs was done and supplemented with chemical GCT is rare. 4,5 Unni 4 has reported an incidence of 1.7% in cautery using phenol solution. Bone cement was used to the hand and 1.2% in the foot. Multicentric giant cell tumor fill the cavity and to extend curettage limits chemically and (MCGCT) is even more infrequent, occurring in less than thermally [ Figure 4]. 1% of patients with GCT; 1,3,6 more than one lesion may be noted at initial presentation in different anatomic locations Follow-up was uneventful for 18 months; she then started or at different times at separate anatomic locations, where complaining of pain in the same (right) forefoot at the local spread cannot be perceived to have occurred. Around base of the third toe. Examination revealed swelling and 100 cases of MCGCT have been reported in the literature tenderness around the base of the third toe; X-rays showed worldwide. [6][7][8][9][10][11] Though many cases of MCGCT have an osteolytic lesion in the proximal phalanx of the third toe been reported with involvement of the foot along with [ Figure 5]. Serum biochemistry including serum calcium, different bones in the body, there has been no mention of phosphate and alkaline phosphatase were done and were multicentric nonadjacent site involvement of the same foot.
within normal limits. Excision biopsy of the local lesion We are reporting one such case.

DISCUSSION
GCT of the foot in itself is a rare occurrence. [9][10][11] Most of these lesions are found in the tarsal bones and involvement of the forefoot bones by GCT is very uncommon. Though involvement of more than one bone in the foot itself is not a rarity we did not find any report wherein the initial lesion started in the foot and remained confined to the foot without a clinically or radiologically identifiable lesion in other parts of the skeleton, as in our case.
MCGCT, when compared to solitary GCT, is encountered more frequently in the short bones of the hand and feet; nevertheless the knee is still the most common site. 3,6,10, 12 Hoch et al 13  When there is foot involvement, MCGCT has been known to involve the calcaneum, talus, navicular and cuneiform either as the first or subsequent tumor but involvement of forefoot bones 3,6,12,14 is very rare [ Table 1].
MCGCT tends to involve the younger population compared to solitary GCT, with mean age reported between 20-24 years. 6,10, 13 The rarity of MCGCT demands a careful scrutiny of other conditions that can present with similar clinico radiological and histological features. Hyperparathyroidism (Brown tumor) with multiple lytic lesions is a very important differential and it can be differentiated on clinical, radiological and histological grounds. 2,10, 15 The current case had normal serum calcium, serum phosphate and serum alkaline phosphatase and the histological picture was characteristic of a GCT. Other differential diagnoses worth mentioning are fibrosarcoma, Paget's disease,