-Rearranged Enteric Tumors: Updates on Clinicopathologic and Molecular Genetics Features.

Recent advances in molecular genetics, particularly in identifying and characterizing genetic abnormalities within mesenchymal neoplasms, have led to a more comprehensive and evolving classification system. Modern technological developments in cytogenetics and next-generation sequencing have enabled the analysis of small clinical samples, expanded our understanding of tumor biology, and improved the diagnostic, prognostic, and predictive precision by identifying targeted genetic alterations, confirming the presence of fusion transcripts, and/or revealing the overexpression of specific genes and their targets. In this review, we focus specifically on the -rearranged enteric tumor, a recent clinicopathological entity that has emerged within the expanding classification of mesenchymal tumors.

Large-cell Basaloid Adenocarcinoma of the Lung: A Clinicopathologic Study of 12 Cases of a Distinctive Form of Lung Cancer Often Mistaken for Large-cell Neuroendocrine Carcinoma.

A distinctive form of lung adenocarcinoma that closely mimics large-cell neuroendocrine carcinoma is described. The tumors arose in 6 women and 6 men aged 46-86 years (mean=58.4).

Nodular Fasciitis of the Buccal Mucosa with a Novel USP6 Gene Rearrangement: A Case Report and Review of the Literature.

Nodular fasciitis is a rare but benign fibroblastic proliferation that typically presents as a solitary lesion with rapid growth and variable mitotic activity. The lesions usually occur on the extremities and occasionally in the head/neck region. Involvement of the buccal mucosa is extremely rare with only few reports in the literature; in this case report, we describe a 41 year old female who presented with a 6-month history of a stable intraoral lump at the junction of the upper and lower lip.

Inflammatory Giant Cell Carcinoma of the Lung: Clinicopathologic, Immunohistochemical, and Next-generation Sequencing Study of 14 Cases.

A distinctive histological variant of poorly differentiated, sarcomatoid, non-small cell lung carcinoma characterized by a discohesive population of giant tumor cells associated with prominent interstitial inflammatory cell infiltrates is described. The tumors occurred in 7 women and 7 men, 42 to 72 years of age (mean: 56 y). They predominantly affected the upper lobes and measured 1.

Non-small cell lung carcinoma with clear cell features: a clinicopathologic, immunohistochemical, and molecular study of 31 cases.

Non-small cell lung carcinoma with predominantly clear cell features is a rare histologic presentation of lung carcinoma. We have examined 31 cases of lung carcinomas showing extensive clear cell features. The patients were 10 women and 21 men aged 47-92 years (mean: 70 years).

Palmar Nodular Fasciitis Harboring a Novel Fusion Gene.

The diagnosis of low-grade fibroblastic/myofibroblastic tumors of acral sites can be challenging. These tumors encompass a diverse group of neoplasms with a spectrum of biologic potential ranges from benign to overtly malignant. They often demonstrate significant clinical, radiologic, and immunophenotypic overlap, in which the molecular phenotype may play an important diagnostic role to arrive at the final diagnosis.

Periosteal Fasciitis With Unusual Radiologic Features Harboring a Novel Fusion Gene.

Periosteal fasciitis is a subtype of nodular fasciitis originating from the periosteum. The diagnosis can be challenging and requires radiologic-pathologic correlation. Advances in molecular analysis confirmed that nodular fasciitis and its related lesions harbor a gene rearrangement with one of the several potential partners.

Epithelioid and Clear Cell Solitary Fibrous Tumors: Clinicopathologic, Immunohistochemical, and Molecular Genetic Study of 13 Cases.

Solitary fibrous tumors (SFTs) are ubiquitous soft tissue neoplasms known for their protean histology and potentially aggressive behavior. Although most cases are composed of a monotonous proliferation of spindle cells, some tumors show unusual cytologic features. We have studied 13 SFTs that were characterized by a predominant population of round epithelioid cells with abundant eosinophilic cytoplasm and clear cell changes.

Desmoplastic Adamantinoma-like Thymic Carcinoma: Clinicopathologic, Immunohistochemical, and Molecular Study of 5 Cases.

Five cases of a heretofore unreported rare variant of thymic carcinoma characterized by a striking resemblance to adamantinoma of the mandible are described. The tumors occurred in 4 women and 1 man aged 58 to 76 years (mean: 67.8 y); they arose in the anterior mediastinum and measured from 5.

Spindle Cell Sarcoma of the Uterus Harboring Fusion Gene and Mimicking Endometrial Stromal Sarcoma.

sarcomas are a newly recognized group of exceedingly rare low-grade spindle cell sarcomas that often involve the genitourinary and gynecologic tracts. Due to its deceptively low-grade morphology and the non-specific immunoprofile, these neoplasms may pose a diagnostic challenge by histologically mimicking other entities such as endometrial stromal sarcoma, smooth muscle tumor, or uterine perivascular epithelioid cell tumor (PEComa). Histologically, sarcomas typically show spindle cell proliferation with hyperchromatic nuclei and a generalized cytologic uniformity, arranged in short fascicles and exhibiting alternating zones of hypo- and hypercellularity.

Intramuscular Tenosynovial Giant Cell Tumor Harboring a Novel Fusion Transcript.

Tenosynovial giant cell tumors typically arise in the synovium of joints, bursae, or tendon sheaths. They may occur in an intra- or extra-articular location and can be divided into localized and diffuse types. The neoplastic nature of the lesion has been supported by a recurrent gene rearrangement in a small subset of lesional cells, of which the most common fusion partner is .

Prognostic Significance of Subungual Anatomic Site in Acral Lentiginous Melanoma.

Context.—: Acral lentiginous melanoma is a rare and aggressive type of cutaneous melanoma that arises on the acral skin and the nail unit. The prognostic significance of subungual anatomic site in acral lentiginous melanoma is not established.

Luna stain: a simple and cost-effective diagnostic tool helps in detecting eosinophilic granules deposition of flame figures and aids in diagnosing eosinophilic cellulitis "Wells Syndrome".

We report a rare case of Wells syndrome in which a 61-year-old Caucasian male presented with three distinct skin lesions including a cutaneous bulla, an erythematous plaque, and a linear streak located on the patient's left anterior thigh, left dorsal wrist, and left anterior forearm, respectively. Histologic examination revealed diffuse and interstitial eosinophilic infiltrate admixed with lymphocytes and macrophages that predominantly involve the dermis. Nodular aggregates of eosinophils surrounding dermal collagen fibers suggestive of 'flame figures' were identified.

Prognostic significance of acral lentiginous histologic type in T1 melanoma.

Acral lentiginous melanoma (ALM) is a rare type of cutaneous melanoma with a poor prognosis. It is unclear whether the poor outcome of ALM is due to its inherent disease characteristics or advanced stage at initial diagnosis. To address this question, we retrospectively analyzed the clinicopathologic factors of 828 thin (T1; Breslow thickness ≤1.

Third Line Eribulin for Triple-negative Metastatic Breast Ductal Carcinoma Resulting in Extended Progression-free Survival of 57 Months.

Eribulin is a non-taxane microtubule inhibitor approved for the treatment of metastatic breast carcinoma after two prior chemotherapeutic regimens. We report a patient with extended progression-free survival (PFS) of more than 57 months with metastatic breast carcinoma treated with eribulin in the third-line setting. A 48-year-old lady was diagnosed with stage IIA (pT2N0M0), high grade, triple-negative, invasive ductal carcinoma (IDC) of the left breast on core needle biopsy.

Immunohistochemical and Molecular Features of Melanomas Exhibiting Intratumor and Intertumor Histomorphologic Heterogeneity.

Melanoma is a heterogeneous neoplasm at the histomorphologic, immunophenotypic, and molecular levels. Melanoma with extreme histomorphologic heterogeneity can pose a diagnostic challenge in which the diagnosis may predominantly rely on its immunophenotypic profile. However, tumor survival and response to therapy are linked to tumor genetic heterogeneity rather than tumor morphology.

Cutaneous neoplasms composed of melanoma and carcinoma: A rare but important diagnostic pitfall and review of the literature.

We report two cases of combined cutaneous tumors composed of melanoma and carcinoma. The first tumor presented as a 5-mm pink-blue macule over the right zygomatic arch in an 85-year-old man. Shave biopsy and immunohistochemical studies revealed that the tumor was composed of melanoma (highlighted by SOX10 and MART-1, with high Ki-67 proliferative index) intermixed with nodular basal cell carcinoma (highlighted by pan-cytokeratin and Ber-EP4).

Acquired cutis laxa associated with cutaneous mastocytosis.

Cutis laxa is characterized by dramatic wrinkling of skin that is lacking in elasticity due to inherent defects in dermal elastic fibers. Cutis laxa can be caused by genetic and metabolic disorders. It can also be acquired, possibly resulting from inflammatory processes with destruction of elastic fibers.