Carcinosarcoma of the uterus with melanocytic differentiation

Beyond the WHO 2020 Classification of Female Genital Tumors: Types of Endometrial Cancer: A Pathological and Molecular Focus on Challenging Rare Variants

Endometrial carcinoma is a heterogeneous group of malignancies characterized by distinct histopathological features and genetic underpinnings. The 2020 WHO classification has provided a comprehensive framework for the categorization of endometrial carcinoma. However, it has not fully addressed the spectrum of uncommon entities that are currently not recognized by the 2020 WHO and have only been described in the form of small case series and case reports. These neoplasms represent a real diagnostic challenge for pathologists; furthermore, their therapeutic management still remains controversial and information regarding tumor prognosis is very limited. This review aims to elucidate these lesser-known variants of endometrial carcinoma. We discuss the challenges of identifying these rare subtypes and the molecular alterations associated with them. Furthermore, we propose the need for expanded classification systems that include these variants to enhance clinical outcomes and research efforts. We believe that a better histological typing characterization of these entities may lead to more reproducible and accurate diagnoses and more personalized treatments. By raising awareness of these rare entities, we also hope to encourage further investigation and integration into clinical practice to improve patient care in endometrial carcinoma.

The "Forgotten" Subtypes of Breast Carcinoma: A Systematic Review of Selected Histological Variants Not Included or Not Recognized as Distinct Entities in the Current World Health Organization Classification of Breast Tumors

Breast carcinoma is the most common cancer in women. Nineteen different subtypes of breast carcinomas are recognized in the current WHO classification of breast tumors. Except for these subtypes, there are a number of carcinomas with special morphologic and immunohistochemical features that are not included in the 5th WHO classification, while others are considered special morphologic patterns of invasive breast carcinoma of no special type. In this manuscript, we systematically review the literature on four different subtypes of invasive breast carcinoma, namely lymphoepithelioma-like breast carcinoma, breast carcinoma with osteoclast-like giant cells, signet-ring breast carcinoma, and metaplastic breast carcinoma with melanocytic differentiation. We describe their clinicopathological characteristics, focusing on the differential diagnosis, treatment, and prognosis.

Is Primary Poorly Differentiated Sarcomatoid Malignancy of the Parotid Gland Sarcomatoid Undifferentiated/Dedifferentiated Melanoma? Report of Three Unusual Cases Diagnosed by Fine-Needle Aspiration Combined with Histological, Immunohistochemical, and Molecular Analyses

INTRODUCTION

Poorly differentiated primary sarcomatoid parotid malignancies are extremely rare. These tumors have not been consistently studied by morphology, immunohistochemistry, or molecular techniques.

CASE PRESENTATION

We report three unusual cases of parotid gland poorly-differentiated sarcomatoid malignancy investigated by fine-needle aspiration and studied histologically, by immunohistochemistry and molecular investigations. Aspirates showed poorly specific polymorphous sarcomatoid malignancy in all cases. Histologically, all cases were polymorphous high-grade malignancies, and additionally, one case showed epithelial structures and was finally classified as salivary carcinosarcoma. Immunohistochemistry showed classical melanocytic markers negativity but positivity for PRAME, CD10, and WT1 in all three tumors and for CD56 in two tumors, which can potentially be supportive of melanocytic origin. Although not entirely specific, molecular characterization also suggested the melanocytic lineage of these tumors.

CONCLUSION

Although rare, primary malignant melanoma of salivary gland was already described, but undifferentiated/dedifferentiated amelanotic forms are unknown in this localization up today. Further case reports of similar presentations are required to confirm the unequivocal primary origin of these obscure neoplasms in the parotid gland.

Endometrial carcinoma with diffuse melanocytic differentiation: Clinicopathological and molecular analysis of a case with literature review and focus on differential diagnosis

Herein, we present a clinicopathological and molecular analysis of a case of endometrial carcinoma with diffuse melanocytic differentiation with literature review. A 72-year-old woman underwent hysterectomy due to a 14 cm endometrial mass. On histology, the tumor showed a serous carcinoma component and a solid component with giant eosinophilic and dyshesive multinucleated cells. Differential diagnosis included several entities, such as undifferentiated giant cell carcinoma and carcinosarcoma with rhabdomyoblasts. The solid component showed diffuse positivity for cytokeratin AE1/AE3, Melan A, Cathepsin K and S100, focal HMB45 positivity and loss of e-cadherin. The tumor was p53-abnormal, mismatch repair-proficient and POLE-wild-type. The patient had extrauterine metastases and was alive with disease at 12 months. Previous cases of endometrial and ovarian carcinomas with melanocytic differentiation (n = 7) did not show giant bizarre cells but showed melanin production; all cases were advanced and/or had unfavorable outcomes. In conclusion, endometrial carcinomas with melanocytic differentiation are highly aggressive tumors which should be distinguished from other entities. Being aware of this entity may help not to miss it.

High-grade Urothelial Carcinoma with Malignant Melanocytic Differentiation

Urothelial carcinoma usually shows divergent differentiation and variant histology with squamous and glandular morphology being most common. In this report, we present a case of divergent malignant melanocytic differentiation in a high-grade urothelial carcinoma. A 98-year-old East Asian woman with an anterior bladder wall mass underwent resection, which revealed a high-grade poorly differentiated tumor. A minor component of high-grade papillary urothelial carcinoma and carcinoma in situ is also present. The majority of the tumor cells are morphologically and immunohistochemically consistent with melanoma, a minority of cells are positive for urothelial markers, and rare cells coexpress both melanocytic and urothelial markers. Cells that express melanocytic markers or urothelial markers are intimately admixed together. Taken together, a diagnosis of high-grade urothelial carcinoma with malignant melanocytic differentiation was rendered. This is the first report in the literature of malignant melanocytic differentiation in a high-grade urothelial carcinoma, a finding that may have important diagnostic and therapeutic implications.

Ovarian Sex Cord-stromal Tumors With Melanin Pigment: Report of a Previously Undescribed Phenomenon

We report 2 ovarian sex cord-stromal tumors, a luteinized adult granulosa cell tumor and a cellular fibroma, with melanin pigment. These occurred in 44 and 61-yr-old patients, respectively. As far as we are aware, melanin pigment has not been described previously in an ovarian sex cord-stromal tumor, although it has been reported in a testicular Sertoli cell tumor. We review ovarian neoplasms containing melanin pigment.

Primary endometrial large cell neuroendocrine carcinoma with melanocytic differentiation

High-grade endometrial carcinomas are aggressive neoplasms of difficult histological classification. Neuroendocrine differentiation in endometrial carcinomas is rare. This is the report of an endometrial large cell neuroendocrine carcinoma with foci of melanocytic differentiation in a 75-year-old woman with abnormal post-menopausal uterine bleeding for 2 years. Two initial biopsies were inconclusive. Histopathological examination of the uterus revealed large cell neuroendocrine carcinoma associated with endometrioid carcinoma and foci of melanocytic differentiation, pT3a (FIGO IIIA). There were metastases in the rectum serosa and lungs. After 8 months of diagnosis and surgical treatment, the patient is on chemotherapy and radiotherapy. We highlight the morphological characteristics and criteria that allow the definitive anatomopathological diagnosis, including immunohistochemical markers used to identify the cell types present in this unprecedented association.

The relationship of melanocytic differentiation with prognostic markers in medullary thyroid carcinomas

INTRODUCTION

Medullary thyroid carcinoma (MTC) makes up 5-10% of thyroid malignancies. Small cell, squamous, giant cell or melanocytic differentiation can rarely be seen in MTCs. It is important to determine those with the potential to act aggressively such as cases with melanocytic differentiation at the time of diagnosis.

MATERIALS AND METHOD

A total of 46 MTC cases diagnosed at four different centers between 2002 and 2013 were included in the study. Immunohistochemical (IHC) staining with Melan-A and HMB-45 was performed in all cases.

RESULTS

Six of the 46 MTC cases were medullary microcarcinomas and three were multicentric medullary carcinomas. There were 34 females and 12 males with a mean age at onset of 51.4 years and mean tumor diameter of 23.2mm. Lymph node metastasis (LNM) was found in 13 of the 38 cases that had data regarding the lymph nodes. Immunohistochemically, Melan A staining was seen in four cases. HMB45 staining was seen in four cases. A statistically significant relationship was found between LNM and diameter, Melan A expression (p=0.02, p=0.03 respectively) but there was no significant relationship with HMB45 expression (p=0.07). General survival data were present for 35 of the 46 cases. All cases without lymph node metastasis survived (21/21) while 8 of 11 cases with lymph node metastasis survived among cases with survival data; one case that was diffuse-strong positive for both HMB45 and Melan A was lost due to distant organ metastasis six months after the diagnosis.

DISCUSSION

Should the possibility of melanocytic differentiation be evaluated in cases where melanocytic differentiation is not reflected in the morphology (lack of pigment) in MTCs? We did not come across a study on the subject in the English literature. The effect of melanocytic differentiation on the prognosis in MTCs should be investigated in larger series.

Adrenocortical neoplasia: evolving concepts in tumorigenesis with an emphasis on adrenal cortical carcinoma variants

Adrenocortical carcinoma (ACC) is a rare, heterogeneous malignancy with a poor prognosis. According to WHO classification 2004, ACC variants include oncocytic ACCs, myxoid ACCs and ACCs with sarcomatous areas. Herein, we provide a comprehensive review of these rare subtypes of adrenocortical malignancy and emphasize their clinicopathological features with the aim of elucidating aspects of diagnostic categorization, differential diagnostics and biological behavior. The issue of current terminology, applied to biphasic tumors with pleomorphic, sarcomatous or sarcomatoid elements arising in adrenal cortex, is also discussed. We additionally present emerging evidence concerning the adrenal cortical tumorigenesis and the putative adenoma-carcinoma sequence as well.

Metastatic melanoma with striking adenocarcinomatous differentiation illustrating phenotypic plasticity in melanoma

We report on the highly unusual case of a 75-year-old woman who developed a biphasic right axillary mass of apparent melanoma and adenocarcinoma 13 years after a diagnosis of primary melanoma on her right upper back. The differential diagnosis included a collision tumor and metastatic melanoma with adenocarcinomatous transdifferentiation. We utilized immunohistochemical staining, DNA sequencing, and comparative genomic hybridization (CGH) to characterize this unusual tumor. By immunohistochemistry, the melanomatous component was positive for S100 and Melan-A, and had patchy positivity for cytokeratin. The adenocarcinomatous component was negative for melanoma markers, but was strongly positive for cytokeratin. In addition, the glandular component was positive for CDX-2 and Ber-EP4, giving the distinct histologic and immunohistochemical impression of a gastrointestinal metastasis nested within a deposit of metastatic melanoma. Clinical and radiologic workup failed to reveal a primary gastrointestinal malignancy. Molecular genetic analysis, including DNA sequencing and CGH, revealed that both areas contained an identical NRAS Q61K mutation and had highly similar CGH profiles, including gains of chromosome 1q and losses of 1p, 4, 9, and 10, which are archetypical of melanoma. The NRAS mutation was also identified in a deposit of metastatic melanoma resected 12 years earlier, but was not seen in the patient's nontumorous tissue, indicating that it was somatically acquired. Genetic analyses demonstrate that 2 morphologically distinct tumors arose from a common ancestor melanoma cell that harbored an NRAS mutation and subsequently divergently evolved by the acquisition of additional genomic alterations. Our findings illustrate the ability of molecular analyses to resolve lineage in complex neoplasms and illustrate the phenotypic plasticity of cancer cells.

Uterine carcinosarcomas (malignant mixed müllerian tumours): a review with special emphasis on the controversies in management

Uterine carcinosarcomas (MMMT-malignant mixed Müllerian tumours) are highly aggressive, rare, biphasic tumours composed of epithelial and mesenchymal elements believed to arise from a monoclonal origin. While hysterectomy with bilateral salpingo-oophorectomy remains the mainstay treatment, high rates of recurrence and metastases suggest a need for lymphadenectomy and postoperative adjuvant treatment. There are no established consensus guidelines for therapeutic patient management. Though well recognized that it improves locoregional control, the role of radiation in improving overall survival outcomes remains undecided. Although various combinations of chemotherapy have been explored, an optimal therapeutic modality is yet to be determined. As overall survival rates have not improved in thirty years, it is suggested that targeted chemotherapy and/or a multimodality approach may yield better outcomes. This paper provides a summary of the aetiopathogenesis of carcinosarcomas (MMMT) limited to the uterus with special emphasis on the controversies in the management of these patients.

Melanoma in a carcinoma ex pleomorphic adenoma of the parotid gland: a case report and putative histogenesis

A rare example of melanoma arising in carcinoma ex pleomorphic adenoma is presented. The diagnosis, differential diagnosis, and putative histogenesis of the melanoma component are discussed.

Pathology of uterine malignancies

This overview covers epithelial, stromal and mesenchymal malignancies of the body of the uterus, excluding the cervix. The distinction of type I and type II endometrial adenocarcinoma with the morphological variants of this tumour is discussed and some molecular aspects are explored. The concept of carcinosarcoma representing a metaplastic adenocarcinoma of the endometrium that behaves more like a carcinoma than a sarcoma is explained. Some types of mixed epithelial and stromal neoplasm are described and contrasted with carcinosarcoma. The concept of stromal sarcoma and high-grade uterine sarcoma is described and an outline of malignant smooth muscle tumours of the uterus includes a description of smooth muscle tumours of uncertain malignant potential and worrying benign smooth muscle lesions.