Temporal primary cutaneous carcinosarcoma in the ear: A case report

Carcinosarcoma is a rare biphasic tumor made of two malignant components—the epithelial component and the stromal component—that can develop anywhere on the body, but mainly in sun-exposed areas. We report the case of a 78-year-old male who presented himself with a right temporal tumor in the ear 10 cm in diameter. A biopsy suggested a sarcoma. The patient underwent an extensive surgical resection of the temporal mass and the ipsilateral ear. A microscopic examination of the tumor revealed two intermixed malignant contingents. The epithelial component was made of atypical basaloid cells arranged in nests with peripheral palisading and expressing cytokeratin. The stromal component was made of atypical spindle cells expressing smooth muscle actin (SMA). A diagnosis of primary cutaneous carcinosarcoma with clear margins was reached. The patient is alive and without recurrence after twelve months of a follow-up period.

RARE-63. CYST WALL OF ADAMANTINOMATOUS CRANIOPHARYNGIOMA CONTAINS TUMOR CELLS THAT COULD LEAD TO RECURRENCE AFTER SURGERY

BACKGROUND Adamantinomatous craniopharyngioma (ACP) is the primary subtype of craniopharyngioma in children, frequently with mutations in exon 3 of the CTNNB1 gene. Most ACP consists of both a solid tumor and one or more cysts. Despite surgical resection of the solid tumor followed by radiation, recurrence involving the cystic component is common, suggesting that the cyst wall contains tumor cells. We present here conclusive molecular pathology evidence of the presence of tumor cells in the cyst wall similar to those in the solid tumor. METHODS We used standard H&E staining and immunohistochemistry (IHC) to compare the histopathology characteristics between the matched cyst wall and solid tumor of 11 cases of ACP as well as their CTNNB1 expression and exon 3 mutation. RESULTS Samples of the cyst wall and solid tumor were collected separately during the operation of 11 cases of ACP through careful dissection. The cyst wall showed the nested cell clusters and peripheral palisading epithelium which are identical to those in the solid tumor. The cyst wall and solid tumor both showed Ki67 and nuclear β-catenin expression by IHC. There is no difference in the transcription level of CTNNB1 between the cyst wall and the solid tumor, both being significantly higher than that in normal brain tissue. Exon 3 mutations of the CTNNB1 gene of the cyst wall and the solid tumor are identical in each case. CONCLUSION Follow-up of clinical cases suggests that tumor cells in residual cyst wall may be the cause of recurrence after surgery.

Sex cord-stromal tumor with annular tubules of the ovary – a case report

Sex cord-stromal tumors with annular tubules (SCTAT) of the ovary are rare. They have two clinicalpresentation forms: the syndromic form which is associated with Peutz-Jeghers syndrome and thenon-syndromic form which is frequently seen in the second or third decades. We describe a 25-year-old patient who underwent exploratory laparotomy. Macroscopically large ovarian mass was24.5×24×8 cm in diameter, encapsulated, congested, and lobulated. On the cut section, it wasgreyish with small cystic and hemorrhagic areas. Microscopically, the tumor mass is composed ofmany simple and complex tubular structures that have eosinophilic PAS-positive hyaline globules inthe center and are surrounded by peripheral palisading of the cells. Finally, the tumor was diagnosedas non-syndromic ovarian SCTAT.

Adamantinoma-Like Ewing’s Family Tumor of the Sino Nasal Region: A Case Report and a Brief Review of Literature

Ewing's sarcoma family of tumors (EFTs) are malignant mesenchymal tumors with a predilection for bone and soft tissue. They are characterized by their monomorphic small blue round cell morphology. However rare morphologic variants of EFTs can also show overt epithelial differentiation in the form of squamoid differentiation along with strong cytokeratin expression. This particular subset of EFTs are known as adamantinoma-like EFTs which can be difficult to differentiate from epithelial head and neck malignancies. Here we report a case of sinonasal adamantinoma-like EFT in an 18-year-old male patient. The lesion differed from a typical EFT by means of overt squamoid differentiation which showed a basaloid appearance with peripheral palisading. The immunohistochemistry was positive for pan-cytokeratin, p40, p63, ERG, FLI1, and CK5/6. It was negative for actin, desmin, and WT-1. Initial diagnosis of a basaloid squamous cell carcinoma was made. Further molecular studies were also done due to the complex presentation of the tumor. EWSR testing with break-apart analysis confirmed EWSR1 and FLI1 rearrangements. Further confirmation was done with RT-PCR. The case was found to be positive for EWS-FLI-1 translocation. The revised immunohistochemistry panel showed CD99, ERG, FLI1, and synaptophysin positivity. The lesion was reclassified as an adamantinoma-like ES. Our case reinforces the fact that a subset of EFTs can show histomorphologic and immunohistochemical features of aberrant epithelial differentiation. These cases are difficult to differentiate from usual epithelial malignancies which occur in this region. This diagnostic pitfall can be avoided by the inclusion of CD99 and/or FLI1 in the immunohistochemical assessment of any round cell malignancy at any anatomic location. A strong and diffuse CD99 positivity should prompt molecular testing for the presence of EWSR1 gene rearrangements.

A Case of Tumor of Follicular Infundibulum Involving the Vulva

Tumor of the follicular infundibulum or infundibuloma is a relatively rare benign adnexal tumor usually solitary and located in the head, neck, and trunk. Here we present a 70-year-old woman with a tender vulvar lesion. Histopathologic exam shows a well-circumscribed lesion with a subepidermal horizontally oriented, plate-like proliferation of pale appearing squamous epithelial cells with numerous points of connections with the overlying epidermis and peripheral palisading. Overall these histopathologic features are consistent with the diagnosis of tumor of follicular infundibulum involving genital skin.

Lesions Mimicking Melanoma at Dermoscopy Confirmed Basal Cell Carcinoma: Evaluation with Reflectance Confocal Microscopy

Background: Atypical basal cell carcinoma (BCC), characterized by equivocal dermoscopic features typical of malignant melanoma (MM), can be difficult to diagnose. Reflectance confocal microscopy (RCM) enables in vivo imaging at nearly histological resolution. Objectives: To evaluate with RCM atypical melanocytic lesions identified in dermoscopy, according to common RCM criteria for the differential diagnosis of BCC, and to identify representative RCM parameters for superficial (sBCCs) and nonsuperficial (nsBCCs) basal cell carcinomas (BCCs). Methods: A retrospective analysis of consecutive patients evaluated with RCM, selecting excised lesions classified at dermoscopy with ≥1 score from the re visited 7-point checklist, mimicking melanoma, registered between 2010 and 2016. Cluster analysis identified BCC subclassifications. Results: Of 178 atypical lesions, 34 lesions were diagnosed as BCCs with RCM. Lesions were confirmed BCCs with histopathology. Dermoscopic features included atypical network (55.9%) and regression structures (35.5%) associated with sBCCs, and an atypical vascular pattern (58.8%) and irregular blotches (58.8%) with nsBCCs. Hierarchical cluster analysis identified 2 clusters: cluster 1 (100% sBCCs) was characterized by the presence of cords connected to the epidermis (90%, p < 0.001), tumor islands located in the epidermis (100%, p < 0.001), smaller vascular diameter (100%, p < 0.001) and solar elastosis (90%, p = 0.017), and cluster 2 (nsBCCs 85%) was defined by the dermic location of tumor islands (87.5%, p < 0.001) with branch-like structures (70.8%, p = 0.007) and surrounding collagen (83.3%, p = 0.012), peripheral palisading (83.3%, p = 0.012) and coiled vascular morphology (79.2%, p < 0.001) with a larger vascular diameter (50%, p < 0.001). Conclusions: RCM is able to diagnose BCCs mimicking melanoma at dermoscopy and seems able to identify sBCCs and nsBCCs.

Inverted urothelial papilloma: A review of diagnostic pitfalls and clinical management

Inverted urothelial papilloma (IUP) is a rare, non-invasive endophytic lesion that accounts for 1‒2% of urothelial tumours. On cystoscopy, IUP appears as a pedunculated/papillary mass with a smooth surface. On microscopy, IUP has an endophytic growth pattern with the bulk of the tumour covered by a superficial layer of urothelium, which can be hyperplastic or attenuated. The cytology should be bland, with uniform, spindled cells arranged in anastomosing trabeculae and cords with peripheral palisading of basaloid cells. Exophytic papillae and mitotic activity should be absent or focal. Pseudoglandular spaces and squamous metaplasia may also be present. There are distinct molecular differences between IUP and urothelial carcinoma (UC). IUP rarely has mutations of FGFR3, homozygous loss of 9p21, or gain of chromosomes 3, 7, and 17, whereas these mutations are frequently seen in UC. In addition, IUP is much less likely to have TERT mutations compared to UC. Immunohistochemistry can also be helpful in distinguishing the two entities as IUP is typically negative for CK20 and has a low Ki-67 proliferation index. Positivity for p53 may be seen in a minority of IUP. IUP can recur and be seen in association with UC. Distinguishing IUP from UC can be difficult due to the similarity between the two entities both on cystoscopy and histology, as up to 25% of UCs will also have inverted growth. Given the morphologic variants of IUP and UC, it is possible for a diagnostic error to occur, which can significantly impact patient management.

A Case of Basal Cell Carcinoma with Outer Hair Follicle Sheath Differentiation

A 70-year-old Japanese man presented at our hospital with an asymptomatic, blackish, irregularly shaped plaque with a gray nodule in the periphery on his left lower leg. The lesion had been present for 10 years and had recently enlarged, associated with bleeding. Histopathologically, the tumor consisted of three distinct parts: The first part showed massive aggregation of basophilic basaloid cells with peripheral palisading and abundant melanin granules, and was diagnosed as solid-type basal cell carcinoma. The second part showed aggregation of clear cells with squamous eddies, and was diagnosed as proliferating trichilemmal tumor. The third part showed reticular aggregation of basaloid cells with infundibular cysts in the papillary dermis, and was diagnosed as infundibulocystic basal cell carcinoma. We diagnosed this tumor as basal cell carcinoma with various forms of hair follicle differentiation, including differentiation into the outer root sheath.

Basal Cell Ameloblastoma of Mandible: A Rare Case Report with Review

Ameloblastoma is a slow-growing benign neoplasm that has a strong tendency to local invasion and that can grow to be quite large without metastasizing. Rare examples of distant metastasis of an ameloblastoma in lungs or regional lymph nodes do exist. It has an aggressive and recurrent course and is rarely metastatic. Radiographically it shares common features with other lesions such as the giant cell tumor, aneurysmal bone cyst, and renal cell carcinoma metastasis; a definitive diagnosis can only be made with histopathology. Basal cell ameloblastoma is believed to be the rarest histologic subtype in which the tumor is composed of more primitive cells and has even fewer features of peripheral palisading. Till date, only few cases of basal cell ameloblastoma have been reported in the literature. Considering the rarity of the lesion, we report here an interesting and unique case of basal cell ameloblastoma of the mandible occurring in a very old patient.