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Journal of Cancer Research and Therapeutics, Vol. 7, No. 2, April-June, 2011, pp. 208-210 Case Report Giant cell tumor of the first metatarsal Yasir Salam Siddiqui, M Zahid, Aamir Bin Sabir, Julfiqar Department of Orthopaedic Surgery, Jawaharlal Nehru Medical College, Aligarh Muslim University, Aligarh, India Code Number: cr11051 PMID: 21768717 Abstract Giant cell tumor (GCT) is a benign locally aggressive tumor with a tendency for local recurrence. GCT of metatarsal is of rare occurrence with very few cases reported so far. GCT in this location is rare and should be considered in the differential diagnosis of a destructive bony lesion in both skeletally immature and mature patients. We report the case of GCT of 1 st metatarsal in a 28-year-old female and discuss the difficult aspects of diagnosis. Keywords: Giant cell tumor, metatarsal bones, destructive bony lesion Introduction Giant cell tumor (GCT) is a benign tumor which, however, is locally aggressive and has a tendency for local recurrence. The World Health Organization has classified GCT as an aggressive, potentially malignant lesion. [1] It usually occurs in young adults of 20-40 years in the epiphyseometaphyseal region, with a male preponderance. Nearly 85-90% is found in long bones, of which 50% occurs around the knee. Other frequent sites are distal radius, proximal humerus and fibula. Unni [2] has reported an incidence of 2% in the hand and 1.5% in the foot. GCT of the hand and foot seems to represent a different lesion than conventional GCT in the rest of the skeleton. [3] It has higher incidence of multicentricity, appears in a younger age, and has a shorter duration of symptoms, averaging 6 months or less before a diagnosis is made. [3] The diagnosis of GCT in foot is frequently delayed as symptoms may primarily be attributed to vague foot pathology. When GCT occurs in long bones, plain X-rays demonstrate eccentric osteolytic lesion in the epimetaphysis with absence of periosteal reaction. However, the radiographic features of giant cell tumors at sites other than long bones are non-specific and are not unlike other osteolytic lesions. [4] Magnetic resonance imaging (MRI) provides a more sensitive tool for evaluation of the nature and extent of a tumor and may help in differentiating GCT from other lesions. Furthermore, histological examination is necessary for diagnosis, as clinical presentation and radiological images are not conclusive. The various treatment modalities described for GCT in literature are curettage, curettage and bone grafting, irradiation, amputation, and resection with reconstruction. The treatment of choice is aggressive curettage or en bloc resection because of the higher rate of local recurrence. We present a case of a GCT of the 1 st metatarsal bone in a 28-year-old female, and discuss the difficult aspects of diagnosing GCT at unusual location. Case Report A 28-year-old female presented with swelling over the dorsum of her right foot for 12 months and pain for 5 months. The swelling was insidious in onset and had progressively increased in size. The pain was mild to moderate in intensity, dull, continuous, and relieved by taking medication and rest and aggravated by activity. There was no history of any constitutional symptoms and trauma. Based on benign course of her clinical features and X-ray findings, she was being treated as a case of tubercular osteomyelitis of the 1 st metatarsal at another hospital, but her symptoms failed to resolve; furthermore, the swelling and pain kept on increasing gradually. She visited our institution after taking 5 months of antitubercular treatment. Examination revealed ovoid swelling over the dorsum of right foot opposing 1 st and 2 nd metatarsal with well-defined margins, stretched overlying skin and without any sign of inflammation [Figure - 1]. The swelling was tender, firm in consistency, and the overlying skin was not tethered. X-ray revealed an expansile osteolytic lesion of 1st metatarsal involving the articular surface of cuneiform-first metatarsal joint and metatarso-phalangeal joint [Figure - 2]. The trabeculations in the wall of lesion were also evident on the X-ray. The lesion had replaced the 1 st metatarsal and had infiltrated the surrounding soft tissue. Chest X-ray did not reveal any metastatic deposit. Laboratory investigations including complete blood count, blood urea nitrogen, serum calcium and phosphorous were within normal limits. The Fine Needle Aspiration Cytology (FNAC) report was consistent with the diagnosis of giant cell lesion. As the lesion has infiltrated the surrounding soft tissue (stage III lesion), a reconstructive surgery with fusion of the cuneiform-metatarsal and metatarso-phalangeal joint was planned. Wide excision of the 1 st metatarsal and replacement with a fibular strut graft was done. Ipsilateral iliac crest cancellous bone grafting was also done. The fibular strut graft was chosen because its size and shape matches the metatarsal, and the strength of cortical graft made it possible to ensure appropriate weight transfer. During operation, it was found that the lesion had replaced the 1 st metatarsal and infiltrated the surrounding soft tissues [Figure - 3]. Deep, lateral and medial margins were involved. Postoperative X-ray was satisfactory [Figure - 4]. Gross examination of resected metatarsal revealed that the tumor had destroyed the architecture of the 1 st metatarsal. Biopsy of the excised specimen confirmed the diagnosis of GCT of bone. Postoperative X-rays at 4 months revealed progressive incorporation of fibular graft [Figure - 5]. At 4 months, K-wire was removed and partial weight bearing ambulation was advised, which progressed to full weight bearing over the next 3 months. The gait cycle was altered, following fusion of cuneiform-metatarsal and metatarso-phalangeal joint. The patient complained of stiffness while pushing off the toes. As she was a housewife, she returned to her normal activities without much limitation. Discussion The foot is a site commonly affected by various lytic lesions, and their clinical features often overlap, which results in difficulty in diagnosing these lesions. Therefore, a high index of suspicion is needed when evaluating any tumors of the foot because the compact structure of the foot may delay diagnosis. [5] GCTs are rarely found in the metatarsal bones and tend to be more aggressive than those in other bones. [3] Radiologically, it appears as a solitary, eccentric, geographic lesion extending into the subchondral bone. In about half of the patients, there is a multiloculated appearance of the lesion secondarily to a prominent trabeculation (in fact, pseudotrabeculation due to a osseous sulcus created by endosteal erosion). [6] The GCT in the present case was involving whole of the 1 st metatarsal with infiltration into the surrounding soft tissues. A GCT needs to be differentiated from other lytic lesions, such as tuberculosis, giant-cell reparative granuloma, aneurysmal bone cyst, Brown tumor of hyperparathyroidism and metastatic deposits in the foot. Clinical presentation (age, duration of symptoms) and imaging (expansile nature, site of lesion, extension of the tumor into the soft tissue, absence of periosteal reaction and mineralized matrix) helps in differentiating GCT from other lesions. In the present case, the patient was misdiagnosed as a case of tuberculosis, based on benign course of her clinical features and X-ray findings. It is not uncommon to diagnose such lesion as infection, but the potential for misdiagnosis is more likely in atypical age groups (Baker et al). [7] However, absence of fever, anorexia, loss of weight and response to antitubercular treatment should raise a query on the diagnosis of tuberculosis. Aneurysmal bone cyst (ABC) is mostly seen in the second decade of life and may mimic GCT. Clinically, ABC presents as a firm, slowly enlarging mass in young patients, most commonly in adolescents. [8] The lesion is rarely present in patients above 30 years of age. The natural course of ABC involves continued local growth and destruction, although the tumor is not considered to be a premalignant lesion. Giant cell reparative granuloma is an uncommon, benign, intraosseous reactive lesion for which the radiological and histological features may overlap with GCT. [9] Giant cell reparative granuloma is most commonly seen in patients in their second decade of life and the metatarsus is the prime location for this lesion. Radiographically, giant cell reparative granuloma appears as an expansile lytic lesion with thinned out cortices. Cortical margins in a majority of cases remain intact, unless a pathological fracture occurs. Brown tumor typically involves the diaphysis of long bones. The radiographic and histological features of Brown tumor, GCT, ABC and giant cell reparative granuloma are often indistinguishable. However, Brown tumors were recently reported to have a much more lobulated architectural growth pattern in comparison to GCT and giant cell reparative granuloma. [10] Hyperparathyroidism can be ruled out on the basis of normal serum calcium, phosphorus, and parathyroid hormone levels. Treatment modalities for GCT of the foot comprise curettage, curettage and bone grafting, irradiation, amputation, and resection with reconstruction. Local resection of the affected metatarsal with autograft or allograft replacement is the preferred surgical treatment. In conclusion, this case is presented to emphasize the fact that although the foot is an infrequent site for GCT, the possibility should be kept in mind. Early diagnosis is difficult because of the rarity of the lesion in this location and overlap in clinical presentation. All expansile lytic lesions on radiographs should be supplemented essentially with FNAC or needle biopsy for establishing the diagnosis, as improper diagnosis and treatment may delay and minimize the chances of a salvage procedure. References
Copyright 2011 - Journal of Cancer Research and Therapeutics The following images related to this document are available:Photo images[cr11051f3.jpg] [cr11051f1.jpg] [cr11051f2.jpg] [cr11051f5.jpg] [cr11051f4.jpg] |
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