Osseous metaplasia (OM) of the cervix without involvement of the uterus is an extremely rare entity. Only few cases had been reported in the literature. We reported a rare case of OM of the cervix clinically mimicking cervical cancer. A 52-year-old female presented with chief complaints of leukorrhea and an unusual sensation of mass in the vagina. On clinical examination, the uterus, adnexa, pouch of Douglas, vulva, and perineum-all were normal except the cervix which was hypertrophied with surface irregularities. Histopathological examination of the cervix showed OM of the cervix. Since this is a benign entity, proper diagnosis is essential to avoid misdiagnosis of malignant tumors, especially malignant mesenchymal tumors.

BACKGROUND: Renal Osseous Metaplasia (OM) is a rare condition in which mature bone forms within the renal parenchyma, typically as focal cortical lesions. Although it is usually considered a spontaneous and less pathologically significant lesion, it has been observed in damaged renal allografts and other urinary tract sites. The case we present involves a native kidney with a simple renal cyst, where histopathological examination post-tumor enucleation revealed OM, emphasizing its noteworthy presence in clinical settings.
METHODS: A 37-year-old female with a history of cesarean delivery and recent emergency surgery presented with abdominal and left flank pain. Initial ultrasound revealed a 4.2 cm anechoic cyst in the lower pole of the left kidney, which was confirmed by abdominal computed tomography (CT-scan as a well-defined fluid density cyst with a thick calcified wall. Surgical enucleoresection identified a Stoney hard mass with a unilocular cyst, histopathologically diagnosed as a simple renal cyst with metaplastic bone and hematopoietic elements. The patient had an uneventful postoperative course and remained well during the follow-up.
CONCLUSIONS: Osseous metaplasia (OM) involves extraskeletal bone formation and is associated with factors such as chronic ischemia and inflammation. While rare in renal pathology, it occurs in native kidneys, damaged renal allografts, and the urinary tract, posing radiological challenges in differentiating it from calcification. Accurate diagnosis requires histopathological examination because of the difficulties in distinguishing OM from calcification on imaging studies.
CONCLUSIONS: This case revealed Osseous Metaplasia in a simple cyst of the native kidney, urging vigilance in the diagnosis. While generally benign, its occurrence in damaged renal areas emphasizes its clinical significance, prompting further research. Heightened awareness and thorough examination are crucial for accurate diagnosis and patient management.

Osseous metaplasia of the endometrium is a rare and intriguing pathological condition characterized by the presence of bony tissue within the endometrial cavity. This phenomenon can have significant clinical implications, particularly in the context of infertility. The etiology of osseous metaplasia remains unclear, although various hypotheses have been proposed, including chronic inflammation, dystrophic calcification, and residual embryonic tissue. Clinically, patients may present with secondary infertility, abnormal uterine bleeding, or pelvic pain. Diagnosis can be made based on ultrasonography and histopathological analysis of the endometrial tissue. Treatment typically involves the removal of the osseous tissue via hysteroscopy, which can lead to the restoration of normal endometrial function and potentially resolve infertility. Further research is needed to elucidate the etiological factors and optimize treatment protocols.

Endometrial osseous metaplasia (EOM) is a rare condition characterized by abnormal bone formation in the endometrium. This acts as a foreign body in the uterus. The commonest clinical presentation is secondary infertility. Transvaginal ultrasonography is the mainstay of first-line diagnosis. Hysteroscopy confirms the diagnosis and aids in complete removal. Diagnosis of this condition is crucial as post-treatment fertility outcomes are good. This case highlights the importance of three-dimensional ultrasonography before infertility treatment and after hysteroscopic removal of osseous metaplasia to look for reactive endometrial polyps which may interfere with the embryo implantation and spontaneous conception altering the post-surgical fertility outcome.

Rectal mucosal prolapse is uncommon in children. While most patients present with rectal bleeding and constipation, the occurrence of osseous metaplasia within the prolapsed mucosa is extremely rare. Overlapping clinical, gross, and histological features between rectal mucosal prolapse polyps and malignancy pose a challenge for diagnoses. We describe a case of a 16-year-old male who had a rectal mucosal prolapsed polyp with osseous metaplasia. He initially presented due to periumbilical pain with a sore throat and fever. Incidentally, during the workup of his periumbilical pain, he was found to have a soft tissue mass in his rectum on a CT scan, with a biopsy confirming the diagnosis. The case was complicated by the development of sepsis. The patient was treated with empiric antibiotics and was discharged without further complications.

Osseous metaplasia of the endometrium is a rare entity in which there is presence of mature or immature bone tissue in the endometrium. It is a rare disorder that usually leads to secondary infertility and is frequently associated with recurrent miscarriages and can be rarely asymptomatic. We present the case of a patient with endometrial ossification associated with secondary infertility. The patient presented with excessive vaginal discharge and was undergoing evaluation for secondary infertility. Transvaginal sonography showed a hyperechoic elongated lesion in the endometrium suggestive of endometrial calcification with posterior acoustic shadowing. Diagnostic hysteroscopy was done and the endometrial cavity showed multiple white-colored, solid, fan-shaped structures and bony spicules all over the endometrium, which were removed with a hysteroscopic grasper and sent for histopathological examination (HPE). The HPE confirmed the presence of bony trabeculae along with secretory endometrial glands. There have only been a few cases of endometrial osseous metaplasia reported in India and it is usually an overlooked cause of infertility. Although rare, we should consider this as a probable cause of secondary infertility when the characteristic ultrasound features are visualized and that hysteroscopic resection is the gold standard treatment.

Choanal polyps belong to a special type of nasal polyps, which are quite uncommon if originating from the nasal septum, especially those with osseous metaplasia. In this article, we report the case of a 63-year-old male patient with persistent nasal obstruction on the right side. An irregular light yellow lobulated mass with smooth surface could be visualized in the nasal cavity through nasal endoscopy, arising from the right nasal septum and extending to the nasopharynx. Computed tomography scan showed a large soft tissue shadow of the nasal meatus, with ossified structure in the center. Histopathological biopsy revealed nasopharyngeal mucositis. The patient underwent functional endoscopic sinus surgery and the polypoidal mass sent for histopathological examination proved to be choanal polyps.

Urothelial tumors characteristically occur in elderly persons, more commonly in males with typical complaints of hematuria. Although few studies attempted to describe clinic-pathological features of urothelial malignancies in young patients, due to heterogeneity in the inclusion of age groups under \"young patients\" no reliable conclusions can be derived. Herein, we are describing an interesting case of papillary urothelial neoplasm of low malignant potential with osseous metaplasia in a 19-year-old chronic smoker young patient presented with chief complaints of abdominal pain with a review of the literature.

Pulmonary osseous metaplasia is a disease in which mature bone is found within the parenchyma of the lung. The current study presents a case of pulmonary osseous metaplasia in a 64-year-old female. The patient was previously diagnosed with transitional cell carcinoma (TCC) of the lower ureter. During a routine check-up, an enhancing basal lung nodule was found on chest computed tomography scan, which was suspected to be metastatic lung disease. The patient underwent a thoracoscopic resection of the nodule. The histopathological examination of the specimen confirmed it to be myeloid osseous metaplasia. The disease usually has no significant complications and can also be found in association with other pulmonary diseases. Very limited information is available on the phenomenon; therefore, there is no exact treatment guide for clinicians to follow. In conclusion, myeloid osseous metaplasia of the lung is a rare finding, and based on this report, it may be associated with TCC.

BACKGROUND: Gastrointestinal stromal tumor is considered the most common mesenchymal neoplasm of the gastrointestinal tract. The majority of gastrointestinal stromal tumor cases are located in the stomach and usually affects older adults. Most of gastrointestinal stromal tumor cases are sporadic; however, few have a syndromic association, including Carney triad, Carney-Stratakis syndrome, familial gastrointestinal stromal tumor syndrome, and neurofibromatosis type 1.
METHODS: Herein, we report a rare case of a 54-year-old Middle-Eastern female with multifocal gastrointestinal stromal tumor mixed type (epithelioid and spindle cell type) with osseous metaplasia. Fluoresce in situ hybridization analysis of platelet-derived growth factor receptor alpha revealed deletion in 42% of the tumor cells studied. Interestingly, next generation sequencing revealed platelet-derived growth factor receptor alpha exon 12 mutation (p.Y555C) and exon 14 mutation (p.N659Y).
CONCLUSIONS: In conclusion, osseous metaplasia in GIST is a very rare event and only few cases are reported in the literature. The number of reported cases is inadequate to confirm the pathogenesis and the prognosis.