Atypical lipomatous tumor with osteoid metaplasia – a rare occurrence

The presence of metaplastic ossification within a atypical lipomatous tumour /well differentiated Liposarcoma (ALT/WDLPS) is a rare occurrence. We report a case ALT/WDLPS with unusual extensive metaplastic bone formation in a 30 years female who complained of swelling in the right shoulder for the past one and a half years. Bangladesh Journal of Medical Science Vol.20(1) 2021 p.197-199

Imaging of endometrial osseous metaplasia—an uncommon but treatable cause of infertility

Background Endometrial osseous metaplasia (EOM) is an uncommon condition characterised by metaplastic transformation of endometrial tissue into osteoblasts (mature or immature bone in the endometrium). Etiopathogenesis of EOM is explained by multiple putative mechanisms like dystrophic calcification, metaplastic ossification, retained foetal bones after abortions and genito-urinary tuberculosis. EOM has varied clinical presentation ranging from patient being asymptomatic to secondary infertility. Although hysteroscopy is the gold standard for its diagnosis and treatment, non-invasive imaging comprising chiefly of ultrasonography (USG) is increasingly becoming the mainstay of diagnosis. We aim to present the imaging findings in EOM to acquaint radiologists and gynaecologists with this condition to avert misdiagnosis of this uncommon yet treatable cause of infertility. Results Mean age of patients was 31.4 ± 5.4 (S.D) years. USG revealed linear or tubular densely echogenic endometrium with posterior acoustic shadowing in all the 14 patients. MRI in 3 patients revealed diffuse or patchy areas of T1W and T2W hypointense signal intensity with unilateral (n = 2) and bilateral (n = 1) ovarian cysts. One patient who underwent CT scan revealed dense endometrial calcification. Histopathologic examination (HPE) revealed lamellar (n = 6) or trabecular (n = 4) bone within endometrium (EOM) and inflammatory cells with calcification in four patients (calcific endometritis). Twelve patients conceived after dilatation and curettage within 15 months. Conclusion Familiarity with the imaging appearances of EOM is indispensable to clinch this diagnosis and avert misdiagnosis of this rare but potentially treatable cause of infertility. USG is usually sufficient for diagnosis. MRI and CT are only supplementary tools in difficult clinical scenarios.

Metaplastic Ossification of the Temporal Artery with Osteoclast-Like Giant Cells: A Mimicker of Giant Cell (Temporal) Arteritis

Purpose To describe a patient presenting with suspected giant cell (temporal) arteritis (GCA) in whom subsequent temporal artery biopsy showed luminal narrowing by medial calcification, metaplastic ossification, and fibrointimal proliferation, consistent with calciphylaxis. Methods A 55-year-old man with end-stage renal disease presented with unilateral loss of vision and elevated erythrocyte sedimentation rate and was initially treated as though he had GCA; however, a subsequent temporal artery biopsy showed marked luminal narrowing by medial calcification, metaplastic ossification, and fibrointimal proliferation, consistent with calciphylaxis. In addition, the tunica media of the affected artery contained multinucleate giant cells, but these represented osteoclasts and foreign body giant cells reacting to calcium, rather than a part of GCA. Results This is a rare report of metaplastic ossification and the finding of non-GCA-related giant cells in the tunica media of the temporal artery, thus representing a clinical and histopathologic mimicker of GCA. Conclusions The clinical differential diagnosis of GCA includes other etiologies that can present similarly; however, temporal artery biopsy can discern the underlying pathology. Importantly, the identification of giant cells is not required for the diagnosis of GCA, and likewise, as our case shows, the finding of giant cells in the wall of a temporal artery does not always imply a diagnosis of GCA.

Histological evidence for a supraspinous ligament in sauropod dinosaurs

Supraspinous ossified rods have been reported in the sacra of some derived sauropod dinosaurs. Although different hypotheses have been proposed to explain the origin of this structure, histological evidence has never been provided to support or reject any of them. In order to establish its origin, we analyse and characterize the microstructure of the supraspinous rod of two sauropod dinosaurs from the Upper Cretaceous of Argentina. The supraspinous ossified rod is almost entirely formed by dense Haversian bone. Remains of primary bone consist entirely of an avascular tissue composed of two types of fibre-like structures, which are coarse and longitudinally (parallel to the main axis of the element) oriented. These structures are differentiated on the basis of their optical properties under polarized light. Very thin fibrous strands are also observed in some regions. These small fibres are all oriented parallel to one another but perpendicular to the element main axis. Histological features of the primary bone tissue indicate that the sacral supraspinous rod corresponds to an ossified supraspinous ligament. The formation of this structure appears to have been a non-pathological metaplastic ossification, possibly induced by the continuous tensile forces applied to the element.

Nasal Polyp With Heterotopic Bone Formation (Osseous Metaplasia): A Case Report

Osseous metaplasia is defined by the presence of heterotopic normal bone tissue in a soft tissue. Metaplastic ossification is a rare event in nasal polyps. The authors describe a rare case of bone formation in nasal polyp of a 28-year-old man with chronic right-sided nasal obstruction without history of trauma or allergy symptoms. To our knowledge, this finding has been reported in a few cases in the English medical literature.