Faculty Bibliography

There are few reported cases of non-Hodgkin's lymphoma metastasis to bone in the lower extremities. The authors present a case of cutaneous B-cell lymphoma thought to be in remission, with metastasis to the first metatarsal head with involvement in the synovial tissue of the first metatarsophalangeal joint. Following excision of the lesion, no further treatment was determined to be necessary. The patient was to be observed for local recurrence.

To the best of the authors' knowledge, this is the first published case of monophasic synovial sarcoma (SS) initially diagnosed as Ewing's sarcoma (ES), yet successfully treated with chemotherapy in a 24-year-old patient. The initial diagnosis showed a monotonous round cell tumor and positivity for CD99, characteristic of ES; however, the cytology was negative for the classic EWSR1 rearrangement of ES. The patient was treated with the standard chemotherapy protocol of ES - COG AEWS1031 Regimen A with vincristine, doxorubicin, cyclophosphamide, and mesna - as well as with wide resection. Post-resection tissue submission showed additional morphologic features which led to a re-evaluation of the classification of the tumor as well as additional molecular studies; these revealed positivity for translocations of SS18 (18q11.1) in 100% of the nuclei, which is most characteristic of SS, thus, reclassifying the neoplasm as a SS tumor. This case underscores the importance of considering several pathologic entities in the differential diagnosis of small, round blue cell tumors, including ES, SS, and lymphoma. It also demonstrates the importance of using chromosomal identification for a more definitive diagnosis, rather than relying on histological features and markers which are found in more than one tumor classification. There is conflicting evidence of the impact of chemotherapy on survival in SS, as it is primarily treated with radiation therapy. Since SS is rare, prospective studies on the effect of chemotherapy on survival are limited in number. However, our case study demonstrates that chemotherapy is another modality that can be used in the treatment of SS neoplasms.

Ultrasound-guided hookwire localization was initially introduced to facilitate the excision of nonpalpable breast lesions by guiding surgical exploration, thereby reducing operative time and morbidity. The same technique has since found utility in a range of other applications outside breast and can be useful within the musculoskeletal system. Despite this, there remains limited literature with respect to its technical aspects and practical utility. We describe our technique and a series of preoperative ultrasound-guided wire localizations in the musculoskeletal system to assist surgical excision of 4 soft tissue masses.

Adenomyoepitheliomas (AMEs) of the breast are uncommon and span the morphologic spectrum of benign, atypical, in situ, and invasive forms. In exceptionally rare cases, these tumors metastasize to regional lymph nodes or distant sites. In the era of genomic characterization, data is limited regarding AMEs. The aim of this study was to provide insight into the molecular underpinnings of a spectrum of AMEs. Seven cases of AMEs of the breast (benign-1, atypical-2, in situ-1, invasive-3) were identified in our files. The seven samples were interrogated using the Oncomine Comprehensive Assay v3 (ThermoFisher). Two atypical AMEs and the malignant in situ AME harbored the same gain-of-function PIK3CA mutation. The malignant in situ AME also showed EGFR amplification, not described previously. Both a benign AME and a malignant invasive AME shared the same gain-of-function AKT1 variant. The benign AME also showed a GNAS mutation. Moreover, the same gain-of-function HRAS mutation was present in an atypical AME and a malignant invasive AME. We also identified co-occurring HRAS and PIK3CA mutations in an ER-positive atypical AME, which has not been previously described. No fusion drivers were detected. We describe the molecular characteristics of the spectrum of AME tumors of the breast, which harbor alterations in the PI3K/AKT pathway. Our findings are clinically relevant with respect to the current options of targeted therapy in the rare instances where malignant AME tumors of the breast progress.

Thus far, only a single case describing an atypical appearance of elastofibroma dorsi at a prior thoracotomy site has been published in the literature. We describe a series of three cases recently imaged at our institution with the same atypical appearance, in order to highlight and increase recognition of this more unusual morphology in post-operative patients.

Here we present a case of a 38 year old male with an incidentally found right upper lobe lung mass. The patient underwent thoracoscopic resection of the mass which revealed a myxoid spindle cell lipoma. This is an exceedingly rare location for this tumor biology and here we discuss its pathological features and treatment options.

OBJECTIVE:To present the clinical, radiologic, and pathologic findings of a patient with carotid intimal sarcoma. METHODS:Detailed medical interview, neurologic examination, and diagnostic evaluation including CT angiography head and neck, MRI brain and neck, digital subtraction angiography, and biopsy of the mass were performed. RESULTS:We report a patient who presented with symptoms of multifocal, bilateral strokes over weeks caused by an enlarging tumor thrombus associated with an intimal sarcoma of the carotid artery. The presence of a carotid space mass encasing the left internal carotid artery was initially not recognized on imaging and was mistakenly attributed to soft atheromatous plaque rather than tumor thrombus. Rapid disease progression resulted in multiple intracranial metastases from tumor embolization. CONCLUSION/CONCLUSIONS:Clinical and radiologic findings of intimal sarcoma may be similar to those of thrombotic disease. However, patients with sarcoma may show an associated perivascular soft tissue mass and an unusual distribution of vessel stenosis. Reevaluation of imaging should be considered in patients presenting with initial imaging findings suggestive of rapidly progressive thrombotic disease who have a poor response to antithrombotic therapy and do not follow an expected clinical course.

A 72-year-old woman who presented with right-sided epiphora and conjunctivitis underwent a probing and irrigation procedure with normal results. She improved with antibiotic-steroid drops. A swelling in the medial canthal region completely resolved. One year later, she returned with symptoms of dacryocystitis. An external dacryocystorhinostomy was performed. Characteristic dacryoliths were removed from the sac lumen, and biopsy of the sac wall showed spicules of lamellar bone within a fibrous stroma. Diagnosed as fibrous dysplasia of the lacrimal sac, this rare entity represents the second such case in the literature.

Tenosynovial giant cell tumor (TGCT) is a benign neoplasm characterized by recurrent fusions involving the colony-stimulating factor 1 (CSF1) gene and translocation partners including collagen type VI alpha 3 chain (COL6A3) or S100 calcium-binding protein A10 (S100A10). Herein, we report three atypical TGCT cases with very unusual morphology comprising areas with increased cellular atypia, mitotic activity, and worrisome features that harbor unique non-CSF1 gene fusions. Anchored multiplex PCR (AMP) for next-generation sequencing utilizing a customized panel targeting 86 cancer-related genes was performed, and it identified novel non-CSF1-driven gene fusions: NIPBL-ERG, FN1-ROS1, and YAP1-MAML2. Screening of three control TGCTs with conventional morphology found translocations involving CSF1, with partner genes COL6A3, FN1, and newly identified KCNMA1. All novel fusions were further validated by reverse transcriptase-PCR (RT-PCR) and Sanger sequencing. Late and multiple local recurrences occurred in the atypical TGCTs, while no recurrences were reported in the conventional TGCTs. Our findings reveal that atypical TGCTs harbor gene fusions not implicating CSF1 and suggest that non-CSF1 fusions potentially confer greater propensity to recurrences and local aggressiveness while indicating the presence of alternate pathogenic mechanisms that warrant further investigation.

Chondromyxoid fibroma (CMF) is a rare benign bone neoplasm that typically occurs in young adults. Juxtacortical or surface-type CMF are rarer still and we present the case of a surface-type CMF in a 78-year-old woman, with only one other case described in a patient of a similar age previously. This patient was an otherwise healthy woman who presented for evaluation of a palpable lump in the anterior proximal tibia. Initial radiographs obtained demonstrated a focal soft tissue fullness immediately anterior to the anterior cortex of the proximal tibia, which contained faint chondroid-like matrix internally. There was associated scalloping of the anterior tibial cortex. MRI confirmed the presence of a juxtacortical, enhancing lesion. Subsequent excisional biopsy was performed and histopathology demonstrated features, which was consistent with surface-type CMF. At a 6-month follow-up the patient remained free of recurrence. In a patient of this age, paraosteal chondrosarcoma should be excluded. Surface-type CMF, although rare, has been described in older patients and while it is unlikely to feature in a list of differential considerations on initial imaging, awareness of the entity is important.