Giant ulcerative benign osteochondroma of shoulder

Osteochondromas in hereditary multiple exostosis have increased risk of malignant transformation as compared with solitary osteochondromas. We present a case of a 54-year-old man who presented to us with complaints of swollen mass of the left shoulder with an ulcerative lesion. Radiograph showed a sessile growth from the proximal humerus and scapula. MRI revealed a sessile osteochondroma measuring about 11×10.1×8.0 cm. The malignant nature of the disease was anticipated due to increased cap thickness and non-healing ulcer, however, biopsy showed a benign lesion without any sarcomatous change. The patient was successfully treated with extra-periosteal excision and was recurrence-free at 24 months follow-up. This case illustrates an extra-articular giant osteochondroma of the proximal humerus, with possible signs of a malignant lesion but diagnosed benign on biopsy. We conclude that a biopsy should always preclude definitive management as this can change the overall mortality and morbidity of the patient.

Malignant Transformation of Monostotic Fibrous Dysplasia after Surgery: A Case Report

Introduction: Fibrous dysplasia (FD) is a benign lesion characterized by replacement of normal bone with abnormal connective tissue. It occurs in monostotic or polyostotic forms, with a rare but proven potential for malignant transformation. Symptoms of acute pain, rapid swelling, or an enlarging mass should increase suspicion for possible sarcomatous change. Complete surgical resection is the mainstay of treatment, and chemotherapy is recommended to improve survival. Case Report: A 52-year-old male presented with a painful, enlarging mass on the right proximal thigh 2 years after undergoing plate fixation of the distal femur for a pathologic fracture secondary to monostotic FD. Diagnostic imaging revealed signs of recurrence, and core needle biopsy revealed aggressive features suggestive of malign ant transformation. Following surgical resection and chemotherapy, the outcome has been uneventful without evidence of recurrence or metastasis at 4-year post-operation. Conclusion: Malignant transformation in monostotic FD is rare. Symptom exacerbation should increase the suspicion for sarcomatous change and prompt the need for diagnostic imaging as well as histologic confirmation.

Unsupervised Resolution of Histomorphologic Heterogeneity in Renal Cell Carcinoma Using a Brain Tumor–Educated Neural Network

PURPOSE Applications of deep learning to histopathology have proven capable of expert-level performance, but approaches have largely focused on supervised classification tasks requiring context-specific training and deployment. More generalizable workflows that can be easily shared across subspecialties could help accelerate and broaden adoption. Here, we hypothesized that histology-optimized feature representations, generated by a convolutional neural network (CNN) during supervised learning, are transferable and can resolve meaningful differences in large-scale, discovery-type unsupervised analyses. METHODS We used a CNN, previously trained to recognize brain tumor histomorphologies, to extract 512 feature representations from > 550 digital whole-slide images (WSIs) of renal cell carcinomas (RCCs) from The Cancer Genome Atlas and other previously unencountered tumors. We use these extracted feature vectors to conduct unsupervised image-set clustering and analyze the clinical and biologic relevance of the intra- and interpatient subgroups generated. RESULTS Within individual WSIs, feature-based clustering could reliably segment tumor regions and other relevant histopathologic subpatterns (eg, adenosquamous and poorly differentiated regions). Across the larger RCC cohorts, clustering extracted features generated subgroups enriched for clinically relevant subtypes (eg, papillary RCC) and outcomes (eg, survival). Importantly, individual feature activation mapping highlighted salient subtype-specific patterns and features of malignancies (eg, nuclear grade, sarcomatous change) contributing to subgroupings. Moreover, some proposed clusters were enriched for recurring, human-based RCC-subtype misclassifications. CONCLUSION Our data support that CNNs, pretrained on large histologic datasets, can extend learned representations to novel scenarios and resolve clinically relevant intra- and interpatient tissue-pattern differences without explicit instruction or additional optimization. Repositioning of existing histology-educated networks could provide scalable approaches for image classification, quality assurance, and discovery of unappreciated patterns and subgroups of disease.

A rare case of atypical lipoma in retropharyngeal space and review of literature

<p class="abstract">The term atypical lipoma was introduced to describe the relatively benign course of well-differentiated liposarcomas when they occur in extremities compared to their retroperitoneal counterparts. A 32-year-old lady presented with dysphagia, excessive snoring and difficulty in breathing for three months<span>. On examination, a smooth globular retropharyngeal swelling was seen extending anteriorly till epiglottis obscuring the view of vocal cords. The CECT scan demonstrated features suggestive of a lipomatous lesion with possible sarcomatous change. Excision was done through a transcervical approach and histopathology showed features suggestive of atypical lipoma of retropharyngeal space</span>. As the tumor was removed in toto, adjuvant radiotherapy was not advised. Hence if any swelling in the retropharyngeal space is noted, the probability of soft tissue tumors must be ruled out by a CT/MRI scan before attempting incision and drainage or any other surgical procedure. Postoperative adjuvant radiotherapy is limited to high-grade tumors, incompletely excised tumors and more radiosensitive liposarcoma subtypes such as myxoid sarcomas.</p>

Tumour in a tumour: a well-differentiated spindle cell sarcoma within a forearm lipoma

Lipomas are common, benign, soft tissue masses in adults. Sarcomatous change within a giant lipoma is a very rare event. We present a case of a woman presenting with a forearm lipoma that subsequently developed a central, well-differentiated, spindle-cell sarcoma within the lipoma. This case underlines the importance of identifying red flags for referral of soft tissue tumours.

Scapular Osteochondroma: An Infrequent Case

Osteochondroma of the scapula is a rare benign tumor in view of its location, which produces pain and mechanical dysfunction of the joint when it is on the ventral surface of the scapula, mainly affecting men during bone growth periods, between the ages of 10 and 30, accounting for 14.4 % of all scapula tumors and 49 % of benign tumors of the scapula. They arise in the metaphyseal regions of the long bones (femur, humerus, tibia), causing mechanical irritation leading to functional impotence, bursitis, and fracture of the scapula. Few cases in flat bones have been described. Diagnosis is made with physical, clinical and complementary examinations, and must be confirmed by prior histopathology biopsy. The surgical indication includes mechanical dysfunction of a joint or tendon in relation to the size of the lesion, sarcomatous change being the procedure of choice in open surgical excision. The case of an 11-year-old girl who was diagnosed with a subscapular osteochondroma after previous excisional biopsy, is described below.

Mesenteric lipomatosis presenting as abdominal mass with concurrent ileal gastrointestinal stromal tumour (GIST): an unusual presentation

Lipomas are benign tumours consisting of mature fatcells and are perhaps the most common neoplasm. It can be solitary or multiple occurring throughout the whole body, but it can rarely originate in the intestinal mesentery. These tumours have very little potential for malignancy with the incidence of sarcomatous change in less than 1% of cases. Concurrent occurrence of gastrointestinal stromal tumour which arises from the mesenchymal components of the gastric and small bowel mucosa is a rarity. Here we present a rare case of mesenteric lipomatosis presenting as mass per abdomen which on evaluation and exploration of abdomen turned out to be multiple mesenteric lipomas with another hard mass arising from the antimesenteric border of the small intestine (ileum), for which mesenteric lipoma excision and resection of hard mass along with the segment of ileum and end to end anastomosis was done.