Human Pathology: Case Reports最新文献

To date, reported cases of ectopic prostatic tissue occurring in the genitourinary tract, particularly in the anterior urethra, are exceedingly rare. We report a case of a 20-year-old man who is presented with cystic lesion on the anterior (penile) urethra. Routine investigation shows a micro-cystic submucous mass, near to the external orifice of the urethra. The performed surgical excision and histological investigation confirm that the lesion is a prostatic tissue ectopy. Histologically and immunohistochemically, the cyst wall is lined with prostatic-type benign epithelium. In addition, interspersed foci of eosinophilic metaplasia (EM) are found among the prostatic epithelium. The subsequent targeted histochemical, immunohistochemical, and ultrastructural study confirm the presence of EM in the ectopic prostatic tissue. This is the first case that presents EM occurring in ectopic prostatic tissue. The presence of EM can be used as an additional argument supporting the prostatic origin and the benign character of the lesion. The histogenesis of the ectopic prostatic tissue in the urethra is discussed. We suggest that it is most likely a hyperplastic epithelial response of embryonic prostatic nests in the urethra.

Interdigitating dendritic cell sarcomas (IDCS) are very rare and aggressive neoplasms that arise from antigen presenting cells. It usually involves lymph nodes, but extra nodal sites are also involved including head & neck region. We report four cases of IDCS involving head & neck region. There were two males and two female patients. Age range was 27 – 75 years. Three cases were extra nodal in location such as mandible, nasoethmoidal region and tonsils. Other case involved right cervical lymph nodes. There were varied histomorphological patterns ranging from spindled to epithelioid appearance, with one case resembling Inflammatory myofibroblastic tumor. All the cases were variably positive for S100, CD68 & LCA. Ki67 index ranged from 10 to 30%. All patients underwent resection with two of them received adjuvant chemotherapy and the other two patients received adjuvant radiotherapy. Two patients had no evidence of disease as on 3 years follow-up. One patient succumbed to the disease in few weeks. One patient was lost to follow-up. Although the incidence of IDCS is extremely rare, this case series highlights the fact that these neoplasms should be considered as differentials in unusual looking tumours.

Urothelial rests are a very rare incidental finding in the vermiform appendix; herein we report the fourth of such a case in a 33-year-old male who presented with acute appendicitis and who was also found to have two incidental foci of well-differentiated neuroendocrine tumour in the vermiform appendix.

Pathological diagnosis of colorectal adenocarcinoma is typically straightforward. However, undifferentiated colorectal cancers can be rarely encountered in daily practice and definitive diagnosis can be very challenging. In this report, we presented a rare case of ascending colon ulcerated mass from a 60-year old man. The mass showed lobulated solid growth pattern, pushing border, no desmoplasia, no glandular formation, no tumor budding, undifferentiated morphology with pleomorphism and multinucleated giant cells, numerous atypical mitosis (>100/5 mm²) and unusual immunophenotype as follows: pancytokeratin+, CK7−, CK20−, CDX2 focally+, SATB2−, DOG1+, CD138+, mucicarmine+. Molecular test showed classic mutations in APC, TP53, SMAD4 and HNF1A, and wild type in BRAF, KRAS and NRAS. Interestingly, KIT, ERBB4 and PIK3CA showed missense mutation, and PDGFRA showed nonsense mutation, although all of them had uncertain clinical significance. Final diagnosis of undifferentiated adenocarcinoma was rendered after combining the growth pattern, immunostains and mucicarmine stain, molecular test findings, and excluding other poorly differentiated malignancies.

In this report, we describe a case of a biphasic tumour which presented as an incidental lump on the wrist of a 78 year old female. The epithelioid component predominated and was strikingly “gland-like”, and in an elderly female raised concerns of a primary soft tissue tumour as well as a metastatic mixed Müllerian tumour. The unusual “gland” lining cells and odd central secretion did not fit classical glands and raised our suspicions of synovial sarcoma. We employed a panel of immunoperoxidase stains to consider synovial sarcoma as well as metastases, and included PAX8, ER and PR for possible gynaecologic and breast malignancies. Paired Box (PAX) 8 is a tissue-specific transcription factor protein, and immunohistochemical stains using antibodies raised against PAX 8 are frequently used in staining panels to help identify the origin of primary or metastatic malignancies, and in particular where tumours from the female genital tract, kidney, thyroid and thymus are included in the differential diagnosis. Our research into PAX8 revealed that it has been little studied in soft tissue sarcomas and there is limited published data in the English language literature regarding PAX8 staining particularly in primary extremity soft tissue synovial sarcomas. Unexpectedly, our panel of immunohistochemical stains showed PAX8 positivity for both the epithelioid and spindle cell components of our case, and again raised concerns of a gynaecological malignancy. The components showed differential PAX8 staining patterns, which is of note, and highlights the possible variability in staining of synovial sarcoma. Definitive diagnosis of biphasic synovial sarcoma was confirmed by fluorescent in situ hybridisation studies. This case report therefore documents PAX8 positive staining in biphasic primary soft tissue synovial sarcoma, demonstrating important considerations in its use, enabling the diagnosis of this infrequent and potentially aggressive soft tissue tumour. The relevant literature is highlighted. The variable range of appearances of this potentially aggressive tumour is further illustrated by our case which showed striking epithelial-rich morphology, and presented important diagnostic considerations. Careful morphologic examination together with immunohistochemical and molecular studies in our case enabled a definitive diagnosis of this histologically striking variant, with unexpected PAX8 positive staining.

Cystic lesions of the spleen are rare and challenging to diagnose, often generating a broad differential diagnosis. However, a comprehensive approach which includes molecular studies, may result in an accurate diagnosis and further provide insight into underlying etiologies. In this study, we report an extensive analysis of a rare solid variant of splenic mesothelial cyst by utilizing clinical, imaging, gross, histopathologic, immunohistochemical and molecular findings.

Sclerosing pneumocytoma (previously called pulmonary sclerosing hemangioma) is a very rare benign pulmonary neoplasm. Diagnosis of this tumor can be problematic especially on the small biopsy specimens. Here, we report a massive 13.5 cm sclerosing pneumocytoma in a 61-year-old female who presented with progressive shortness of breath and underwent lobectomy procedure. Radiological findings, gross and histological features, immunohistochemical staining profile as well as differential diagnoses are discussed in detail. The purpose of this case study is to increase awareness of this entity among physicians and to further aid in proper clinical management.