Papillary thyroid carcinoma (PTC) is the most common primary thyroid malignancy. PTC is diagnosed based on its hallmark nuclear characteristics, but a myriad of histological variants has been identified some of which can be diagnostically challenging due to its rarity and overlapping histomorphology with other entities. We report a rare variant of PTC with lymphoepithelial features which lacked association with Epstein-Barr Virus (EBV). In such cases, a thorough workup to rule out metastasis from other sites should be undertaken.

Benign osseous tumors of mesodermal origin that are included within the group of fibro-osseous lesions include cemento-ossifying fibromas (COFs). The fibrocellular component of these diseases originates from the periodontal ligament, which deposits bone and cementum encased in fibrous tissue. It typically appears in the mandible and presents as a solitary, nonaggressive, slowly developing, asymptomatic, expansile lesion, rarely occurring in the maxilla. The only intervention that proved to be successful in producing excellent outcomes and that may be regarded as a final therapeutic option is the complete surgical removal of COFs. Presenting herein is a case report describing a painless and expansile mass in the left mandibular region, histopathologically diagnosed as COF.

Psammocarcinoma (PsC) represents a rare form of low-grade serous tumor of the ovary or peritoneum. Although ovarian cancer generally has a poor prognosis in its late stages, PsC seems to have a more indolent course. We present a patient with a history of unspecific abdominal pain for more than a year, with sudden acute onset of severe inguinal pain. On admission to the hospital, a computed tomography (CT) revealed a pelvic mass of suspected ovarian origin. Radical surgery was attempted but not achieved due to widespread tumor growth. Histopathological evaluation revealed estrogen receptor-positive stage III PsC. Tamoxifen treatment was thus initiated, still maintaining stable disease 10 years later. The patient has undergone extensive radiological work-up, including CT, chest X-ray, 18F-fluoro-deoxy-glucose positron emission tomography (PET)/CT, 99mTc- hydroxymethylene diphosphonate (HDP) bone scintigraphy, 18F-fluoro-thymidine (FLT) PET/CT, Tc-99m depreotide scintigraphy and magnetic resonance imaging. In conclusion, we demonstrate that PsC has characteristic radiological features and different imaging modalities can be suitable in different clinical situations. In contrast to most other ovarian cancers, PsC does not always warrant adjuvant chemotherapy, even in advanced stages. This emphasizes the need for a deeper knowledge of the biological behavior of this rare tumor, to select the optimal treatment strategy.

Melanotic schwannoma is a rare form of nerve sheath tumor composed of melanin-producing neoplastic Schwann cells. Less than 200 cases have been reported worldwide. The entity has been associated with Carney complex, a rare genetic disorder characterized by multiple benign tumors. A 38-year-old female presented to our unit with sudden-onset lower back pain and radiculopathy triggered by a mechanical injury. Imaging demonstrated a lesion within the left L5/S1 neural exit foramen with remodeling of bony architecture typical of a chronic, benign process. She proceeded for resection and histology revealed a psammomatous melanotic schwannoma. The patient recovered well with improvement in symptomology. Due to the aggressive nature of the disease, she remains under surveillance for local recurrence and distant metastasis. Clinicians should be aware of this malignant entity, despite its possible presentation with radiological features of a chronic, benign process. Unusual characteristics such as hemorrhage should be treated with a high index of suspicion.

Calcification in lung nodules usually indicates a benign lesion. Here, we report the case of a 59-year-old male patient with a well defined 30 mm calcified nodule in his right upper lung lobe and calcified mediastinal lymph nodes. The mass was diagnosed as adenocarcinoma by transbronchial biopsy. He received systemic chemotherapy, followed by lobectomy and mediastinal lymph node dissection. During surgery, the lymph nodes were tightly adherent to the superior vena cava with invasion of the vascular wall. Pathological diagnosis confirmed acinar adenocarcinoma and psammoma bodies (PBs). Immunohistochemical analysis revealed tumor cells positive for parathyroid hormone-related proteins 1 and 2. Calcification of primary lung adenocarcinoma is rare. We report a calcified lesion where the secretion of parathyroid hormone by the tumor may have caused the accumulation of PBs. Calcification of metastatic lymph nodes may increase the risk of adhesion, requiring care during surgery. KEY POINTS: Significant findings of the study Lung adenocarcinoma with extensive calcification in primary and metastatic lymph node lesions is rare and the mechanism involved is poorly understood. Of significance, calcification in our case was related to parathyroid hormone-related proteins 1 and 2 secreted by the tumor. What this study adds This study suggests the potential role of parathyroid hormone-related proteins in lung tumor calcification. The implications for clinicians are that calcified metastatic lymph nodes and tumors might be tightly fused to tissues. Therefore, surgery should be conducted with care.

Calcifying fibrous tumor is a rare soft tissue benign tumor (OMS 2002). Some pleural localisations are described, which affect slightly older individuals than the other soft tissue forms. The calcifying fibrous tumor is included in the 2004 World Health Organization classification of pleural tumors. A pleural tumor located in the right inferior pulmonary lobe is diagnosed in a 59-year-old man. This pleural tumor is macroscopically well-circumscribed. Histologically, the rare spindle tumoral cells are located between bundles of a collagenous tissue, sometimes hyalinized, with psammomatous or dystrophic calcifications. The tumoral cells have a fibrohistiocytic origin. They stain positively for antibodies against vimentin, factor XIIIa, CD68, CD163, CD34. Antibodies against smooth muscle actin, desmin, PS100, ALK1 and EBV are negative. Main differencial diagnoses are other benign pleural tumors (solitary fibrous tumor, inflammatory myofibroblastique tumor), some malignant tumors (desmoplastic malignant pleural mesothelioma) and pleural pseudotumors (calcified pleural plaques, chronic fibrous pleuritis, amylose, hyalinizing granuloma). Our case is the 15th pleural calcifying fibrous tumor being reported.

Primary mucinous carcinoma of skin is an uncommonly documented tumor, especially on fine-needle aspiration cytology (FNAC) smears. A 58-year-old gentleman presented with a recurrent swelling over his right zygoma. Earlier, he had undergone surgical resection at the same site, on two occasions, 4 years back. FNAC smears from the recurrent nodule displayed clusters and singly scattered relatively monomorphic, polygonal to plasmacytoid cells with mild nuclear atypia and moderate to abundant cytoplasm, including focal intracytoplasmic vacuoles. At places, tumor cells were arranged around psammoma bodies against a background of mucinous material. Histopathological sections from the subsequent tumor resection revealed tumor cells arranged in the form of islands, nests, cribriform, and papillary arrangements amidst mucinous stroma, along with focal psammomatous calcification, consistent with a recurrent mucinous adenocarcinoma. On immunohistochemistry, tumor cells were diffusely positive for CK 7, estrogen receptor (ER), and progesterone receptor (PR), while negative for CDX2, CK20, and TTF1. Diagnosis of a recurrent mucinous carcinoma of skin was offered. Patient underwent adjuvant radiotherapy for achieving better loco regional clearance and is disease-free, 4 months after. FNAC is a useful diagnostic tool for timely identification of mucinous carcinoma of skin, including recurrent lesions. Psammomatous calcification can be identified within this uncommon tumor, in recurrent lesions. While surgical resection remains the treatment mainstay, immunohistochemical expression of ER and PR in this tumor perhaps could have therapeutic impact, especially in recurrent cases.

Pure mucinous carcinoma of the breast accounts for about 2% of all breast carcinomas and is associated with a favourable prognosis due to its lower nuclear grade and infrequent axillary or hematogenous metastases. Micropapillary variant of mucinous carcinoma breast has recently received attention as a unique form of invasive carcinoma of the breast exhibiting dual differentiation towards mucinous as well as micropapillary. The characteristic features for labeling a tumor as mucinous micropapillary carcinoma are micropapillary pattern, nuclear pleomorphism, hobnail cells and psammoma bodies in addition to the predominant mucinous component. Micropapillary mucinous carcinoma (MUMPC) when compared to pure mucinous carcinoma tends to have a higher nuclear grade, axillary lymph node metastases, lymphovascular invasion and overexpression of Her 2, p53 and Ki-67, thereby displaying an aggressive clinical behaviour. We present a rare case of micropapillary mucinous carcinoma to highlight the fact that this being a unique and rare variant of mucinous carcinoma should be recognized and reported as a separate category by the pathologists owing to its aggressive clinical behaviour and its influence on the nature of therapy.

Serous psammomacarcinoma of ovary is a rare ovarian carcinoma. We present the imaging features of this condition in a patient with a probable metastatic subcutaneous nodule.