Chondroblastoma of trapezium with metacarpal involvement

Posted on November 10, 2008

By Eiichi Konishi, MD, PhD; Takako Okubo, MD, PhD; Megumi Itoi, MD, PhD; Yasukazu Katsumi, MD, PhD; Hiroaki Murata, MD, PhD; Akio Yanagisawa, MD, PhD
ORTHOPEDICS 2008; 31:395

Chondroblastomas typically affect the epiphysis of the long bones in young patients, and only rarely occur in elderly patients >70 years.1-6 Approximately 10% to 20% of chondroblastomas are located in the small bones of the hands or feet; however, they are rare in the carpal bones.2-12 Chondroblastoma is a benign tumor, and it may not only show aggressive clinical course but also pulmonary metastases.2-4,6,13,14

This article presents a case of chondroblastoma originated in the right trapezium of a 75-year-old woman, involving the proximal half of the first metacarpal.

Case Report

A 75-year-old woman reported a painless, slowly growing mass in her right wrist for approximately 1 year before presenting to the hospital. At presentation, an elastic firm nodule (4 cm in greatest diameter) with ill-defined margins was detected around the trapeziometacarpal joint of the right thumb. It did not adhere to the skin, but was not movable. Range of motion of the right thumb was decreased. No inflammation around the mass was noted. No neurological abnormalities were detected in either the right wrist or hand. Results of laboratory tests, including serum levels of calcium and phosphorus, were within normal limits.

Plain radiographs of the right wrist revealed a large lytic mass in the trapezium, with marked cortical expansion and thinning (Figure 1A). The proximal half of the first metacarpal also exhibited lytic change with mild to moderate expansion of the cortex. No obvious calcification was noted within the lesion.

Computed tomography (CT) of the right wrist revealed a large lytic lesion originated in the trapezium. On plain CT, thin cortical bone was occasionally found at the periphery of the expansile bulging lesion. The tumor was enhanced with contrast material. The cortex of the first metacarpal disappeared in the portion facing the large bulging lesion. On magnetic resonance imaging (MRI), the tumor exhibited iso- to hypointense signal on T1-weighted images (Figures 1B, 1C) and inhomogenously hyperintense signal on T2-weighted images (Figure 1D). The tumor exhibited an expansile growth with distinct margins.

A linear, hypointense signal was noted at almost the entire circumference of the tumor on both T1- and T2-weighted images (Figures 1C, 1D, arrow-head). Small round hyperintense foci were scattered within the tumor on T2-weighted images (Figure 1D), sometimes with fluid-fluid levels (Figure 1D, arrow), suggesting cystic change. The tumor involved the proximal half of the first metacarpal (Figure 1B, #). A direct extension to the first metacarpal bone from the large overhanging tumor originating in the trapezium was suspected (Figure 1B, arrow). A tumor growth via trapeziometacarpal joint was also suspected (Figure 1B, arrow-head). Gadolinium-enhancement was not performed.

One month after presentation, biopsy was performed to exclude malignancy, especially metastatic carcinoma, due to the patient’s age and aggressive radiological features. Two months after presentation, with a histological diagnosis of benign primary bone tumor, resection of the right trapezium and proximal half of the first metacarpal was performed with iliac crest bone grafting.

Macroscopically, cut surface of the resected specimen exhibited a well-bordered inhomogeneously brownish tumor (Figure 1E). Small cystic spaces with hemorrhagic content (Figure 1E, arrow) were observed. Yellowish discoloration was seen in the metacarpal (Figure 1E, #). Hyaline cartilaginous tissue was observed in connection with the articular cartilage faced trapeziometacarpal joint (Figure 1E, arrow-head).

Histologically, a vague lobular proliferation of mononuclear cells and pink chondroid matrix were seen. The mononuclear tumor cell had singular oval nucleus without atypia. Cytoplasms of the mononuclear cells had distinct borders, and epithelioid features were occasionally noted. Multinucleated osteoclastic giant cells were randomly distributed (Figure 1F). In addition, mononuclear cells sometimes showed nuclear grooving. So-called “chicken-wire” calcification was not noted. Mitotic figures were present (2/10 HPF), but no atypical mitosis was noted. Small secondary aneurysmal bone cysts were scattered throughout the lesion. Conventional hyaline cartilage was only noted in the operated specimen as hypertrophic joint cartilage. Small aggregates of foamy cells were detected in the tumor, often in the metacarpal. The cortical bone of the trapezium was very thin and remained at the periphery of the tumor. However, there were microscopic foci of soft tissue permeation through the periosteum. The metacarpal involvement was due to the direct extension from the bulging tumor of the trapezium, and via the trapeziometacarpal joint capsule. Vascular invasion was not identified. Immunohistochemically, the tumor cells were reactive for S-100 protein (Figure 1F inset).

Although the tumor showed an aggressive growth pattern, based on both histological and immunohistochemical findings, the diagnosis of benign chondroblastoma was confirmed. Follow-up plain radiographs of the patient’s right hand has not shown any recurrent lesion for 49 months postoperatively. No tumor has been found in other portions of skeleton in thallium scintigraphy.

Discussion

Chondroblastoma usually affects the epiphysis of the long bones and is rare in the carpal bones.2-6 Only 18 cases have been reported.2-5,7-12 The bone of origin varied, and the most common site in the carpal bones was the scaphoid (6 of 18 cases),3,10,11 followed by the capitate (3 cases),3,9,10 lunate,10,12 and triquetrum (2 cases, respectively).8,10 One was in the hamete7 and trapezium.3

Typically, chondroblastoma affects young patients, and >50% of patients are in the second decade of life.2-6 Among .600 cases of chondroblastoma, <5 cases occurred in the patients >70 years.2-6 Of the 18 previously reported patients with chondroblastoma in the carpal bones–patient information was available for 13–11 were <30 years.2-5,7-12

Chondroblastoma is a benign tumor; however occasionally histologically typical chondroblastomas showed “aggressive” clinical features, such as frequent recurrences, large tumor size and soft tissue extension. 2-4, 6,13,14 Approximately 5% of chondroblastoma showed cortical and soft tissue permeation, histologically, and approximately 12% made soft tissue mass, radiologically.3 In the 18 cases of chondroblastoma of the carpal bones, description of radiological features was available for 5 cases.7-9,11,12 In these 5, no soft tissue mass was reported.7-9,11,12 One reported case of histologically typical chondroblastoma had a similar growth pattern to our case.15 In that case, chondroblastoma of talus had a direct extension to the adjacent calcaneus.15 Like our case, chondroblastomas of unusual sites, such as flat bones, small bones, and temporal bone, more frequently show unusual clinicopathological features, including soft tissue extension and older age.1-3,5 Furthermore, chondroblastomas of unusual sites may show the extension to the articular surface and the cortical expansion, more frequently than in long bones.3 “Benign” chondroblastoma in small bones might mimic the locally aggressive lesion.

Based on the patient’s age and the locally aggressive radiological features, the clinical differential diagnosis of our patient included metastatic tumor, primary bone tumor of low-grade malignancy (eg, conventional chondrosarcoma), giant cell tumor, and giant cell reaction (including solid-type aneurysmal bone cyst, giant cell reparative granuloma and so-called brown tumor). It was impossible to obtain a correct diagnosis only with clinicoradiological findings. Although showing an aggressive growth pattern in gross, it had typical histological features of chondroblastoma. Immunoreactivity for S-100 protein also helped to eliminate other lesions.

In general, simple curettage with or without bone grafting yields successful results in most chondroblastomas. Overall local recurrence rates are around 15%.5 Local recurrence occurs more often in flat than in long bones.1,5 No report exists on the recurrence rate of chondroblastoma in carpal bones. Of the 18 previously reported cases, follow-up with description of the surgical procedure was available only for 4 cases.7,9,11,12 Two were treated by simple excision and 2 by curettage, and no recurrence occurred in these 4 cases.7,9,11,12 Whether prognosis of chondroblastoma in carpal bones is better or worse than that in other skeletons, is unclear. Moreover, because our patient exhibited an extension into the adjacent bone, careful follow-up is recommended.

References

  1. Bertoni F, Unni KK, Beabout JW, Harner SG, Dahlin DC. Chondroblastoma of the skull and facial bones. Am J Clin Pathol. 1987; 88(1):1-9.
  2. Dahlin DC, Ivins JC. Benign chondroblastoma. A study of 125 cases. Cancer. 1972; 30(2):401-413.
  3. Kurt AM, Unni KK, Sim FH, McLeod RA. Chondroblastoma of bone. Hum Pathol. 1989; 20(10):965-976.
  4. Schajowicz F, Gallardo H. Epiphysial chondroblastoma of bone. A clinico-pathological study of sixty-nine cases. J Bone Joint Surg Br. 1970; 52(2):205-226.
  5. Turcotte RE, Kurt AM, Sim FH, Unni KK, McLeod RA. Chondroblastoma. Hum Pathol. 1993; 24(9):944-949.
  6. Unni KK. Dahlin’s Bone Tumors: General Aspects and Data on 11,087 Cases. 5th ed. Philadelphia, PA: Lippincott-Raven; 1996.
  7. Daly KE, Chow JW, Vickers RH. Excision of the hamate for an unusual hand tumour. J Hand Surg [Br]. 1993; 18:606-608.
  8. Davila JA, Amrami KK, Sundaram M, Adkins MC, Unni KK. Chondroblastoma of the hands and feet. Skeletal Radiol. 2004; 33(10):582-587.
  9. Mangini U. Benign chondroblastoma localized in the capitate bone. A case report. Bull Hosp Joint Dis. 1964; 25:50-56.
  10. Murray PM, Berger RA, Inwards CY. Primary neoplasms of the carpal bones. J Hand Surg [Am]. 1999; 24(5):1008-1013.
  11. Ng JP, Lee JC. Test and teach. Number Sixty-two. Chondroblastoma of the scaphoid. Pathology. 1990; 22(1):10, 49.
  12. Tountas CP, Cobb SW. Chondroblastoma of the lunate: a case report. J Hand Surg [Am].1992; 17(3):466-467.
  13. Green P, Whittaker RP. Benign chondroblastoma. Case report with pulmonary metastasis. J Bone Joint Surg Am. 1975; 57(3):418-420.
  14. Mirra JM, Ulich TR, Eckardt JJ, Bhuta S. “Aggressive” chondroblastoma. Light and ultramicroscopic findings after en bloc resection. Clin Orthop Relat Res. 1983; (178):276-284.
  15. Ohno T, Kadoya H, Park P et al. Case report 382: benign chondroblastoma of talus invading calcaneus. Skeletal Radiol. 1986; 15(6):478-483.

Authors

Drs Konishi and Yanagisawa are from the Department of Pathology, Dr Murata is from the Department of Orthopedic Surgery, Kyoto Prefectural University of Medicine, and Dr Okubo is from the Division of Anatomic Pathology, Drs Itoi and Katsumi are from the Department of Orthopedic Surgery, Meiji University of Integrative Medicine, Kyoto, Japan.

Drs Konishi, Okubo, Itoi, Katsumi, Murata, and Yanagisawa have no relevant financial relationships to disclose.

The authors thank K. Krishnan Unni, MB, BS, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota for reviewing the pathological slides.

Correspondence should be addressed to Eiichi Konishi, MD, PhD, Department of Pathology, Kyoto Prefectural University of Medicine, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto, Kyoto 602-8566, Japan.

Posted in Hand/Upper Extremity