Primary synovial epithelioid sarcoma of the knee: distinctly unusual location leading to its confusion with pigmented villonodular synovitis

Delayed diagnosis of pediatric intra-articular epithelioid sarcoma: a case report and literature review

BACKGROUND

Epithelioid sarcoma (ES) is a rare form of mesenchymal malignancy that rarely occurs in children. Only seven cases of intra-articular epithelioid sarcoma have been reported in the medical literature.

CASE PRESENTATION

In this report, we presented the case of a 13-year-old girl with a delayed diagnosis of ES in the left knee. Her initial diagnosis was mistaken for Pigmented Villonodular Synovitis (PVNS) but ruled out later by the first biopsy. However, the lesion rapidly regrew again after arthroscopy, raising suspicions of malignancy. A comprehensive histochemistry examination was conducted again, leading to the diagnosis of INI-1 negative epithelioid sarcoma. Unfortunately, the girl passed away seven months later due to early metastasis of the tumor.

CONCLUSION

Careful consideration should be given to the differential diagnosis of pediatric patients presenting with monoarthritis. This report highlights the importance of early and accurate diagnosis and underscores the necessity for effective treatments for epithelioid sarcoma. Surgical resection or radical surgery is recommended, while novel treatment strategies targeting EZH2 show promise.

Suspected intra-articular soft-tissue tumours and tumour-like lesions: Performance of image-guided core needle biopsy

PURPOSE

To determine the efficacy of image-guided core needle biopsy (IGCNB) in patients presenting with suspected intra-articular soft tissue tumours or tumour-like lesions.

METHODS

Retrospective study of patients referred to a musculoskeletal oncology service between January 2019 and May 2020 with a suspected intra-articular soft tissue tumour over a 16-month period. Data collected included patient age, gender, joint involved and maximal lesion size. Type of image-guidance (ultrasound or computed tomography), type of needle and type of anaesthesia, general anaesthetic (GA) or local anaesthetic (LA), were recorded, as was the histological diagnosis. For patients who proceeded to surgical excision, the IGCNB histology result was correlated with resection histology. Descriptive statistics were used and complications were also noted.

RESULTS

By the termination of data collection 91 patients underwent IGCNB, 32 (35.2 %) males and 59 (64.8 %) females with a mean age of 41.4 years (age range 3-86 years). The joints involved were the knee (n = 73; 80.2 %), ankle (n = 12; 13.2 %), hip (n = 3; 3.3 %), shoulder (n = 1; 1.1 %), elbow (n = 1; 1.1 %) and wrist (n = 1; 1.1 %). Biopsy types were as follows: US-guided GA (n = 29; 31.9 %), US-guided LA (n = 37; 40.7 %), CT-guided GA, (n = 23; 25.3 %), CT-guided LA (n = 2; 2.2 %). Mean maximal tumour dimension for 76 focal lesions was 36.5 mm (range 18-113 mm). IGCNB yielded a definitive histological result in 85 of 91 cases (93.4 %), 44 of whom went on to surgical resection. Concordance between IGCNB and resection histology was achieved in 42 of 44 cases (95.5 %). The commonest diagnosis was tenosynovial giant cell tumour, with only a single malignant lesion identified. There were no recorded immediate or delayed complications.

CONCLUSIONS

IGCNB of suspected intra-articular tumours or tumour-like lesions is a highly effective and safe technique.

Primary intra-articular epithelioid sarcoma of the knee: Unusual presentation of a rare entity

We report a case of a 60-year-old female with severe and progressive pain of her right knee. Physical therapy, pain medication, and arthroscopic debridement were unsuccessful. Finally, pathological examination revealed an intra-articular epithelioid sarcoma, a rare tumor in an atypical location. Patient died within 5 months after initial admission. Despite this unusual clinical course and presentation, we would like to share the valuable clinical lessons we learned from this case. Introduction of a coordinating physician in combination with a multidisciplinary treatment regarding optimal pain management should optimize treatment results in future patients.

Functional Ulnar Nerve Paraganglioma: First Documented Occurrence in the Extremity With Hitherto Undescribed Associated Extensive Glomus Cell Hyperplasia and Tumorlet Formation

Extra-adrenal paraganglioma has never been described in the extremities. A 34-year-old woman complained of an enlarging mass in the right forearm for 18 months. Imaging showed a circumscribed vascular tumor attached to the ulnar nerve; biopsy revealed features of paraganglioma. The resected tumor consisted of zellballen pattern of chief cells staining positively for chromogranin with surrounding S100-positive sustentacular cells. The chief cells contained many neurosecretory granules and mitochondria, whereas the sustentacular cells contained a large amount of rough endoplasmic reticulum and some microfilaments. There was adjacent extensive glomus cell hyperplasia and tumorlet formation. The intraoperative blood pressure dropped abruptly on tumor removal. The serum normetanephrine level decreased from a preoperative level of 1987 pg/mL (normal < 149 pg/mL) to normal after operation. The patient admitted on questioning to a history of paroxysmal attacks of transient palpitation, hand tremors, and sweating; imaging showed no evidence of tumor in other parts of the body, and there was no family history of similar tumor; she remained well 33 months after the operation. This occurrence of functional ulnar nerve paraganglioma with the hitherto undescribed associated glomus cell hyperplasia and tumorlet formation attests to the probable existence of normal sympathetic paraganglia in the extremity and their intimate functional relationship with glomus bodies.

Metatarsal leiomyosarcoma masquerading as acute osteomyelitis - A diagnostic trap unveiled by vigilant clinical, radiologic and pathologic analysis

Due to overlapping clinical and radiological features, the differentiation between osteomyelitis and bone tumor can be challenging. A 48-year-old lady presented with intermittent left foot pain for a few months. Plain radiographs showed an osteolytic lesion affecting the proximal diaphysis of the left fourth metatarsal bone, with thinning and irregularities of the cortex and focal periosteal reaction. Ultrasonography revealed diffuse subcutaneous edema in the dorsum of the left foot, cortical irregularities along the mid-shaft of the left fourth metatarsal bone, and surrounding periosteal collection. Computed tomography showed medullary expansion along the shaft and base of the left fourth metatarsal bone with cortical irregularities and defects suggestive of cloaca, and focal mild periosteal new bone formation. The clinico-radiologic diagnosis was acute osteomyelitis with periosteal collection. During open biopsy, the finding of intramedullary fleshy tissue in the absence of significant inflammatory edema and purulent discharge, and subsequent negative culture result prompted a review of the histologic slides which was initially reported as benign fibroblastic tissue proliferation. Careful analysis of the histomorphology disclosed a spindle cell sarcoma for which ray amputation of the fourth and fifth metatarsal was performed. The final diagnosis was grade 1 leiomyosarcoma and the patient remained well 33 months after the operation.