Pitfalls in the cytological diagnosis of tenosynovial giant cell tumor: An illustration of eight discordant cases

Abstract

Tenosynovial giant cell tumor (TSGCT) is a highly recurrent benign tumor of the extremities. Wide local excision is usually sufficient to achieve its recurrence-free outcome. However, that needs a confident pre-operative cytological diagnosis as TSGCT. Aspirates from this tumor express the characteristic polymorphic cytological pattern, enough to impose a definite diagnosis. However rarely so, inadequate sampling from smaller tumors or due to faulty techniques, and selective sampling from topographic clusters of any individual component may lead to wrong interpretation. An unorthodox location near the larger limb joints further complicates the diagnostic misery on occasions. Such tumors are amenable to incomplete removal and risk for future recurrence. In this report, we describe eight cases of TSGCTs that were cytologically diagnosed otherwise. The cytological features of these discrepant tumors and the factors attributable to such dilemma are elaborated. Finally, a possible remedy has been proposed at conclusion in order to avoid future inconveniences.

Giant cell tumour of tendon sheath: A 10‐year study from a tertiary care centre

“…The non-neoplastic conditions include foreign body granulomas, chronic synovitis and bursal cyst. 9 Inflammatory lesion and sarcoidosis were noted in the present study.…”

“…GCTTS has a wide spectrum of differential diagnoses, including non‐neoplastic and neoplastic conditions. The non‐neoplastic conditions include foreign body granulomas, chronic synovitis and bursal cyst . Inflammatory lesion and sarcoidosis were noted in the present study.…”

“…Osteoclastic giant cells and pigment laden macrophages are not seen in these lesions . Benign fibrous histiocytoma and benign skin adnexal tumours are also close mimickers of GCTTS on cytology …”

“…10 Benign fibrous histiocytoma and benign skin adnexal tumours are also close mimickers of GCTTS on cytology. 9 Various malignant tumours such as malignant fibrous histiocytoma, clear cell sarcoma, malignant giant cell tumour of soft tissue and bone and malignant melanoma can be considered as differential diagnostic entities for GCTTS. 11 The presence of frank features of malignancy in form of nuclear atypia, brisk mitosis, atypical mitosis and necrosis are absent in GCTTS.…”

FNAC study of giant cell tumor of tendon sheath (localized tenosynovial giant cell tumor): Clinico‐radiological correlation and cytopathological features

“…There is a wide spectrum of differential diagnoses for GCTTS, however adequate clinical examination, radiologic features and cytopathological findings can easily lead to the correct diagnosis. The non‐neoplastic and proliferative conditions, which could be confused with GCTTS include proliferative fasciitis, myositis ossificans, chondroblastoma, synovial chondromatosis, chronic synovitis, bursitis, rheumatoid nodule, and foreign body granuloma 1,9,16,21 . Proliferative fasciitis typically have large cells with abundant cytoplasm and prominent nucleoli 16 .…”