Tophaceous pseudogout: a pitfall in the diagnosis of chondrosarcoma

An Unusual Pathologic Ulna Fracture Induced by Intraosseous Tumoral Calcium Pyrophosphate Dihydrate Crystal Deposition Disease

In this case report, we describe a novel occurrence of tumoral calcium pyrophosphate dihydrate crystal deposition disease (TCPPDCD) in a 76-year-old man that presented as an unusual, intraosseous, metadiaphyseal lesion of a long bone causing a pathologic fracture. A routine intralesional biopsy was performed, demonstrating granular deposits composed of polarizing, overlapping rhomboid crystals consistent with TCPPDCD. With limited numbers of reported cases of TCPPDCD, and the atypical intraosseous origin seen in this case, it is paramount to thoroughly evaluate all cases of TCPPDCD to clearly differentiate key findings that are essential in diagnosing and managing TCPPDCD.

Calcium pyrophosphate deposition disease of the temporomandibular joint invading the middle cranial fossa: Two case reports

BACKGROUND

Pseudogout is a benign joint lesion caused by the deposition of calcium pyro-phosphate dihydrate crystals, but it is invasive. Pseudogout of the temporo-mandibular joint (TMJ) is uncommon, and it rarely invades the skull base or penetrates into the middle cranial fossa. The disease has no characteristic clinical manifestations and is easily misdiagnosed.

CASE SUMMARY

We present two cases of tophaceous pseudogout of the TMJ invading the middle cranial fossa. A 46-year-old woman with a history of diabetes for more than 10 years was admitted to the hospital due to swelling and pain in the right temporal region. Another patient, a 52-year-old man with a mass in the left TMJ for 6 years, was admitted to the hospital. Maxillofacial imaging showed a calcified mass and severe bone destruction of the skull base in the TMJ area. Both patients underwent excision of the lesion. The lesion was pathologically diagnosed as tophaceous pseudogout. The symptoms in these patients were relieved after surgery.

CONCLUSION

Tophaceous pseudogout should be considered when there is a calcified mass in the TMJ with or without bone destruction. A pathological examination is the gold standard for diagnosing this disease. Surgical treatment is currently the recommended treatment, and the prognosis is good after surgery.

Tophaceous pseudogout in a 12-year-old dog, with a review of applicable laboratory tests

Pseudogout, also known as calcium pyrophosphate dihydrate (CPPD) deposition disease or chondrocalcinosis, is caused by crystalline deposits of CPPD within the extracellular matrix of articular hyaline cartilage and fibrocartilage, and within articular and periarticular connective tissue. Using a variety of laboratory techniques, we diagnosed pseudogout in the right hindlimb digit V of a 12-y-old Standard Poodle. Histologically, the joint, bone, tendon, and dermis were expanded and effaced by masses of mineralized, rhomboid crystals surrounded by macrophages, multinucleate giant cells, fibrous connective tissue, and chondroid and osseous matrix. Rhomboid crystals exhibiting weak-positive birefringence were identified under polarized light using a first-order red compensator filter. Scanning electron microscopy with energy-dispersive x-ray analysis (SEM-EDXA) revealed that the rhomboid crystals were composed of calcium, phosphorus, and oxygen. Fourier-transform infrared (FTIR) microspectroscopy confirmed the presence of calcium pyrophosphate. In dogs, tophaceous pseudogout, which was the variant of pseudogout in our case, occurs as a single, tumor-like periarticular mass that can be invasive and mimic neoplasia. Having ancillary confirmatory testing (SEM-EDXA and FTIR), particularly in unusual histologic scenarios, such as tophaceous pseudogout in dogs, is desirable for confirming the correct diagnosis, even though it is available only at certain reference centers. The pathogenesis of pseudogout is unknown.

An Unusual Case of Huge Tophaceous Pseudogout Mimicking as a Tumor-Like Lesion around the Ankle Joint: A Case Report and Literature Review

Pseudogout or calcium pyrophosphate dihydrate deposition disease (CPPD) primarily affects the joints and the periarticular tissues. Tophaceous or tumoral pseudogout is a rare form of this disease which is seen around the joints of extremities. It can be misdiagnosed as a neoplastic condition because of its clinicoradiological similarities, and thus, a proper histopathological examination is indispensable. We report one such case of extra-articular deposition of the CPPD crystals in a 65-year-old man who presented with an asymptomatic swelling around the left ankle. Radiographs showed a dense homogenous calcification, and FNAC revealed dense calcium deposits with numerous rhomboid-shaped crystals. It was managed by en bloc excision, and postoperative biopsy reports confirmed the diagnosis. Possibility of pseudogout should be kept as a differential diagnosis in patients presenting with calcified soft tissue swellings and should be subjected to a detailed histopathological examination for confirmation.

Dual-Energy Computed Tomography Demonstrating Destructive Calcium Pyrophosphate Deposition Disease of the Distal Radioulnar Joint Mimicking Tophaceous Gout

Calcium pyrophosphate dihydrate deposition (CPPD) disease is a common etiology of crystalline arthropathy; however, it can manifest in multiple patterns such as acute calcium pyrophosphate (CPP) crystal arthritis, osteoarthritis with CPPD, and chronic CPP crystal inflammatory arthritis. Tumoral or tophaceous-like CPPD is a rare manifestation that is occasionally mistaken for gouty tophus or a soft tissue malignancy. Dual-energy computed tomography (DECT) is a new imaging modality currently utilized in assessing monosodium urate crystal deposition; however, its value in CPPD is uncertain. We describe a case using DECT to diagnose tumoral CPPD mimicking tophaceous gout versus recurrence of a previous synovial sarcoma. The imaging findings on DECT prevented unnecessary surgery to assess for possible malignancy, allowing for the prompt diagnosis of tumoral CPPD. Further studies should be performed to determine the role of DECT in assessing for crystalline deposition disease other than gout.

Tophaceous calcium pyrophosphate dihydrate deposition disease of the knee mimicking an aggressive soft tissue tumour

Calcium pyrophosphate crystal deposition disease (CPPD), previously pseudogout, is the second most common crystal arthropathy after gout. There is increased radiographic prevalence associated with age, trauma and several metabolic disorders. Tophaceous CPPD (T-CPPD) is a rare form of CPPD which, though non-neoplastic, mimics a bone or soft tissue malignancy. T-CPPD usually presents as a mass in the temporomandibular joint and occasionally in the paraspinal tissues, but rarely in the joints of the extremities. We present an exceptionally rare case of T-CPPD that was subtle on plain radiography, presenting as a soft tissue mass in the knee joint.

Huge tophaceous pseudogout associated with tenosynovial chondromatosis arising from flexor digitorum tendon sheaths of the foot: a case report

Synovial chondromatosis (SC) is a benign proliferative process of synovial tissue creating multiple cartilaginous nodules in joints. It most commonly occurs in the large joints of the knee, hip, and shoulder, uncommonly in the small joints of the hand and foot, and only rarely in the tenosynovial membrane of tendon sheath, termed tenosynovial chondromatosis (TC). Unlike SC, TC predisposes to the foot or hand. The rarity and unfamiliarity of imagers with TC, as well as the variability of its histologic features often lead to an erroneous diagnosis of extraskeletal chondroma or even chondrosarcoma as in the present case. Calcium pyrophosphate dehydrate (CPPD) crystals are usually deposited in the articular cartilage or periarticular structures such as synovium and capsule, and rarely in other soft tissue structures including bursa, tendon, subcutaneous tissue, and dura mater. CPPD crystals may also be deposited in extraskeletal chondroma and SC. We present an exceptionally rare case of huge tophaceous pseudogout associated with TC that is considered to arise from the flexor digitorum longus tendon sheaths of the foot, initially mistaken for a chondrosarcoma.

Mimicry in older patients: tophaceous pseudogout as a tumorlike lesion: a case report

Pseudogout is frequently seen in painful arthritis of larger joints, especially the knees and shoulders. This case report describes a rare clinical entity of soft-tissue calcium pyrophosphate dihydrate crystal deposition disease surrounding the second metatarsal bone of an 81-year-old man with moderate painful swelling of the right forefoot for 2 years. Diagnostic imaging demonstrated a calcified soft-tissue tumor adjacent to the second metatarsal bone by considering a neoplastic process in the differential diagnosis. Excisional biopsy revealed a chalklike material on the calcified soft tissue that was pathognomonic for chondrocalcinosis or pseudogout. The excisional biopsy findings led to stagnation of the clinical symptoms, and no recurrence of the initial tumor was seen during 12-month follow-up. In the literature, only 28 cases of tophaceous pseudogout tumors in the extremities have been described. In these cases, the lesions were suspected of being chondrosarcomas. For this reason, a correct diagnosis has to be pursued by performing a biopsy to treat the disease correctly.

Tophaceous pseudogout of the ankle: case report

Level of Evidence: V, Expert Opinion

Tophaceous pseudogout in the knee joint mimicking a soft-tissue tumour: a case report

Tophaceous pseudogout in the knee joint is rare. We report an 82-year-old man who presented with a one-year history of pain and swelling of the right knee joint. Treatment with non-steroidal anti-inflammatory drugs and aspiration of the joint effusion had not been effective. The mass continued to enlarge, and the patient had difficulty walking. Radiographs and computed tomography showed meniscal calcification with an abnormal soft-tissue mass surrounded by calcification. After excision, massive calcified deposits were seen both inside and on the surface of the tophaceous pseudogout. The deposits showed birefringence under polarised light, suggestive of calcium pyrophosphate dihydrate crystals. At the 2-year follow-up, the patient could walk independently without knee pain or swelling, although his range of knee motion was slightly limited due to joint contracture that developed before surgery.

Tumoral calcium pyrophosphate dihydrate crystal deposition disease: a rare diagnosis by fine-needle aspiration

Calcium pyrophosphate dihydrate crystal deposition disease (CPPD) is a well-recognized inflammatory joint disorder characterized by presence of calcium pyrophosphate dihydrate crystals in intraarticular and periarticular tissue. We report here a case of a 48-year-old male who presented with painless right hand swelling. Clinical suspicion was that of malignant soft tissue tumor. Fine-needle aspiration (FNA) yielded chalky white gritty material. Microscopic examination showed large areas of basophilic calcified material, histiocytes, giant cells and characteristic rhomboid shaped crystals. At places, chondroid material was also identified, hence, diagnosis of CPPD was made. This was confirmed on histopathological examination. Tophaceous/ tumoral pseudogout is a rare form of CPPD and it is important to recognize that this form can be diagnosed in FNA cytology (FNAC) and misdiagnosis of benign or malignant cartilaginous lesions can be avoided.

Calcium pyrophosphate dihydrate deposition disease (CPPD)/Pseudogout of the temporomandibular joint - FNA findings and microanalysis

We report a case of a Calcium pyrophosphate dihydrate deposition disease (CPPD) presenting as a mass in the parotid and temporomandibular joint (TMJ) that simulated a parotid tumor. A 35 year-old man presented with pain in the left ear area. A CT Scan of the area showed a large, calcified mass surrounding the left condylar head, and extending into the infratemporal fossa. FNA of the mass showed birefringent crystals, most of which were rhomboid with occasional ones being needle shaped, embedded in an amorphous pink substance. Scanning electron microscopy (SEM) with energy dispersive x-ray spectroscopy (EDS) of these crystals showed peaks corresponding to calcium and phosphorus. SEM/EDS is a rapid method of diagnosing calcium pyrophosphate dihydrate deposition disease (CPPD) and an alternative to more commonly used method of special staining of cell block sections coupled with polarizing microscopy.