Cutaneous Melanocytic Tumor with CRTC1::TRIM11 Fusion: Review of the Literature of a Potentially Novel Entity

“Cutaneous melanocytic tumor with CRTC1::TRIM11 fusion” (CMTCT) is a recently described entity belonging to the family of superficial tumors displaying melanocytic differentiation. Thirteen cases have been reported so far, on the head and neck, extremities, and trunk of adults of all ages (12 cases) and one in an 11-year-old child. Histopathologically, it is a nodular or multilobulated tumor composed of spindle and epithelioid cells arranged in nests, fascicles, or bundles that are surrounded by thin collagenous septa. By immunohistochemistry, the tumor shows variable immunoreactivity for S100-protein, SOX10, and MITF, as well as specific melanocytic markers such as MelanA and HMB-45. The neoplasm’s biologic behavior remains uncertain since the reported cases are limited and the follow-up is short (median 12 months). However, local recurrence and synchronous distant metastasis after 13 years of initial resection has been described in one case. Herein, we present a comprehensive literature review of CMTCT hoping to raise awareness among the dermatopathologists of this potentially novel entity.

Progress of the Art of Macrophage Polarization and Different Subtypes in Mycobacterial Infection

Mycobacteriosis, mostly resulting from Mycobacterium tuberculosis (MTb), nontuberculous mycobacteria (NTM), and Mycobacterium leprae (M. leprae), is the long-standing granulomatous disease that ravages several organs including skin, lung, and peripheral nerves, and it has a spectrum of clinical-pathologic features based on the interaction of bacilli and host immune response. Histiocytes in infectious granulomas mainly consist of infected and uninfected macrophages (Mφs), multinucleated giant cells (MGCs), epithelioid cells (ECs), and foam cells (FCs), which are commonly discovered in lesions in patients with mycobacteriosis. Granuloma Mφ polarization or reprogramming is the crucial appearance of the host immune response to pathogen aggression, which gets a command of endocellular microbe persistence. Herein, we recapitulate the current gaps and challenges during Mφ polarization and the different subpopulations of mycobacteriosis.

MUSCULAR TUBERCULOSIS: RARE PRESENTATION OF A COMMON ENTITY

Tuberculosis is a global health problem mainly affecting people in developing countries although muscular involvement is rarely seen. Authors hereby, describe a case of tuberculosis of triceps muscle in a 35-year-old immunocompetent female who presented with swelling in right upper arm. Radiological examination ruled out involvement of underlying bones. Excision biopsy was performed and on histopathological examination cyst wall showed presence of foamy macrophages in sheets, inammatory cells and few scattered epithelioid cells but no well-formed granulomas or giant cells were seen. ZN stain for acid fast bacilli was positive. Based on the above ndings a diagnosis of tuberculosis of triceps muscle was made. The patient responded well to antituberculosis therapy and is currently on follow up.

Feline sarcomatoid renal cell carcinoma with peritoneal carcinomatosis and effusion

A 9-y-old, castrated male, domestic medium-hair cat diagnosed previously with chronic kidney disease developed anorexia and vomiting. Ultrasonography revealed abdominal effusion and a left renal perihilar mass. Cytologic evaluation of the peritoneal fluid and mass identified atypical epithelioid cells suspected to be of renal epithelial or possible mesothelial origin. Immunohistochemical (IHC) evaluation of a formalin-fixed, paraffin-embedded peritoneal fluid cell block indicated both pancytokeratin and vimentin expression in the atypical epithelioid cell population. With scanning electron microscopic evaluation, similar epithelioid cells lacked the cell-surface microvilli expected of mesothelium, supporting an antemortem diagnosis of probable carcinoma. On postmortem examination, the left kidney was effaced by an infiltrative neoplasm with myriad similar nodules throughout the peritoneum. The neoplasm was composed primarily of polygonal-to-spindle-shaped cells with strong vimentin and weak pancytokeratin cytoplasmic immunolabeling. Further IHC characterization with PAX8, CK18, KIT, napsin A, SMA, desmin, CD18, and claudin 5 was performed. Histologic and IHC findings supported a diagnosis of sarcomatoid renal cell carcinoma with peritoneal carcinomatosis. An in vitro cell culture line of neoplastic cells harvested from the primary tumor was successfully established for future research endeavors.

Pancreatic Gangliocytic Praganglioma: A Rare Case and Literature Review

Introduction/Objective Gangliocytic paraganglioma, GP is a morphologically distinct tumor first reported by Dahl in 1957, most often in second portion of duodenum near ampulla of Vater. GP mostly present as single tumors, but occasionally may be multiple, when seen in association with Von Recklinghausen disease and carcinoid tumors. Rare cases have been reported at other sites in gastrointestinal tract including esophagus, pylorus, jejunum and extra- gastrointestinal tract in the nasopharynx, thymus, lung and ovary. Pancreatic GP is extremely rare with five cases reported till date. Methods/Case Report A 42- year- old male presented with abdominal pain. Physical exam showed no abnormalities. The significant findings on labs were raised amylase levels in the range of 1262 U and mild hyperglycemia with blood glucose of 178mg/dl. CA 19-9 was found to be 8.0 U/ml. Coronal CT Abdomen showed hypodense well circumscribed nodule 1.5 cm in body of pancreas. Gross specimen of pancreas showed a circumscribed 1.5 cm nodule in body of Pancreas.The microscopic sections of pancreatic mass show epithelioid appearing neuroendocrine cells in nests, with spindle shaped schwann cells or sustentacular cells in periphery, and scattered ganglion cells. The immunohistochemical staining positive for synaptophysin in epithelioid cells, S100 in spindled schwann cells and CK in epithelioid cells and Ganglion cells. Based on the microscopic findings, a diagnosis of Gangliocytic Paraganglioma, GP arising in Pancreas was made. Results (if a Case Study enter NA) NA Conclusion Pancreatic GP, are often misdiagnosed as Pancreatic Neuro endocrine tumors, Grade1. The accurate differentiation and precise diagnosis is crucial for appropriate clinical management. WHO classification of 2010, classifies gangliocytic paragangliomas as benign. Duodenal GP has a benign behavior with lymph node metastasis in only 5-7% cases, and no evidence of distant metastasis. In comparison, Pancreatic GP show an more aggressive behavior with lymph node metastasis observed in 2/6 cases and one case with sternal bone metastasis, emphasizing the importance of the primary location of origin of GP as prognostic factor. Our understanding is limited due to the scarcity of literature; more published data shall be instrumental in further explaining the clinical behavior of this rare entity.

Analysis of Extended Resection of Limb Soft Tissue Leiomyosarcoma

Leiomyosarcoma is an uncommon soft tissue sarcoma that composed of malignant mesenchymal cells with distinct features of the smooth muscle lineage. Typically affects the uterus and gastrointestinal tract, it can rarely be seen in large blood vessels, lymphatic and glandular duts, the mesentery, the omentum, retroperitoneum, and limbs. Occurrence is particularly rare in the limb region. Retrospective study based on patient records and postoperative pathological histological features. Four patients with limb leiomyosarcoma that were operated between 2016 and 2020 were included, three of them arising in the subcutis of the thigh region and one in cubitus. Extend resection with satisfactory outcomes is reported. Pathological examination showed that masses were composed of a fascicular arrangement of hyperchromatic spindle-shaped cells, characterized by the proliferation of epithelioid cells with eosinophilic cytoplasm for epithelioid leiomyosarcoma. Leiomyosarcomas that arise in the soft tissue, although rare, should be differentiated from other lesions, such as neurilemoma, neurofibroma, liomyoma,lipomyoma, synoviosarcoma, rhabdomyosarcoma, malignant fibrous histiotoma, and malignant neurinoma.

Clinical and histopathological principles for the diagnosis of a recurrent paraganglioma of the jugular foramen initially diagnosed as a middle ear adenoma: illustrative case

BACKGROUND Paragangliomas (PGLs) are rare neoplasms that may be associated with hereditary PGL syndromes and variable risk of metastasis. Middle ear adenomas are extremely rare tumors with no known hereditary predisposition and extremely low risk of metastasis. Although often easily differentiated, they may share clinical and pathological features that misdirect and confuse the diagnosis. OBSERVATIONS The authors discussed a 35-year-old woman with left-sided hearing loss and bleeding from the external ear canal who presented to an outside hospital. She underwent resection of a middle ear and mastoid mass, initially diagnosed as a middle ear adenoma with neuroendocrine features, with later mastoidectomy and ligation of the sigmoid sinus with microsurgical excision of persistent tumor in the jugular foramen and temporal bone. Histopathologically, her tumor was vascular, composed of benign-appearing epithelioid cells with “salt and pepper” neuroendocrine chromatin arranged in vague nests. Lesional cells were GATA3-immunopositive, glucagon-negative, and succinate dehydrogenase-immunonegative, consistent with PGL rather than middle ear adenoma, and required further workup for hereditary PGL syndromes. LESSONS This case demonstrates potential challenges in differentiating a PGL from a middle ear adenoma. The authors offer clinical, histopathological, and imaging principles to aid in diagnosis and workup.

Cutaneous Melanomas Arising during Childhood: An Overview of the Main Entities

Cutaneous melanomas are exceptional in children and represent a variety of clinical situations, each with a different prognosis. In congenital nevi, the risk of transformation is correlated with the size of the nevus. The most frequent type is lateral transformation, extremely rare before puberty, reminiscent of a superficial spreading melanoma (SSM) ex-nevus. Deep nodular transformation is much rarer, can occur before puberty, and must be distinguished from benign proliferative nodules. Superficial spreading melanoma can also arise within small nevi, which were not visible at birth, usually after puberty, and can reveal a cancer predisposition syndrome (CDKN2A or CDK4 germline mutations). Prognosis is correlated with classical histoprognostic features (mainly Breslow thickness). Spitz tumors are frequent in adolescents and encompass benign (Spitz nevus), intermediate (atypical Spitz tumor), and malignant forms (malignant Spitz tumor). The whole spectrum is characterized by specific morphology with spindled and epithelioid cells, genetic features, and an overall favorable outcome even if a regional lymph node is involved. Nevoid melanomas are rare and difficult to diagnose clinically and histologically. They can arise in late adolescence. Their prognosis is currently not very well ascertained. A small group of melanomas remains unclassified after histological and molecular assessment.