Monotypic angiomyolipoma of the nasal cavity: An extremely rare cause of nasal mass with recurrent epistaxis

Monotypic angiomyolipoma is usually found in the kidneys and is composed predominantly of epithelioid cells which show positivity for melanocyte and smooth muscle markers. It can pose a diagnostic challenge due to a range of differential diagnosis. We report the second case of monotypic angiomyolipoma of nasal cavity and first from India in a 54-year-old male who presented with a nasal polyp. Grossly the tumor was well circumscribed and un-encapsulated. Microscopy showed a large number of epithelioid cells mixed with a few spindle cells, varying sized blood vessels, and focal areas of adipose tissue. Immunohistochemistry was positive for smooth muscle actin (SMA) and human melanoma black (HMB-45) stains. It is important to identify this tumor as it can sometimes be mistaken for malignancy and only needs endoscopic resection.

Intravascular and Extravascular Migratory, Metastatic Melanoma of the Great Saphenous Vein

Melanoma blood vessel metastases are very uncommon. Wereport this very rare case of metastatic melanoma along thewall of great saphenous vein (GSV), showing intra and extravascular metastasis. By far only a single case of intravascularmetastatic melanoma (IVMM) of GSV and thirty six cases ofextravascular migratory metastatic melanoma (EVMM) ofGSV have been reported. In our case melanoma cells wereseen both inside and outside of the wall of GSV, and in thedermis. A 60 years old male presented with multiple swellingsupper left thigh since one and a half year. Patient wasoperated. All swellings, along with, part of saphenous vein tillthe knee, and small part of skin were excised under GA.Microscopically, hematoxylin and eosin sections given fromvarious sites showed features of malignant melanoma. Tumorcells were seen in the dermis, and the lumen, as well asoutside the wall of saphenous vein, but not in the epidermis.Only very few melanocytic granules were seen in a singlearea of a section. On Immunohistochemistry –, MarkersHMB45, S100 and Vimentin are strong immunoreactive. CKPAN was focal immunoreactive.In our case the melanoma spread along the wall of the GSV.This pericytic angiotropism of melanoma cells, also showingsigns of intravasation, which suggests that melanomacells may migrate along the external surface of vessels, amechanism termed ‘EVMM and also by invading the bloodvessels ‘IVMM’.

Sporadic lymphangioleiomyomatosis with multiple atypical features: A case report and literature review

Lymphangioleiomyomatosis (LAM) is a rare, genetically determined, progressive interstitial lung disease, which almost exclusively affects women, especially at the childbearing age. The initial symptoms and radiographic changes in a patient with LAM are always associated with the respiratory system. Here, we present a case of mediastinal and abdominal LAM of a 22-year-old male, where LAM cells are negative for human melanoma black-45 ( HMB-45). The report of this uncharacterized LAM case will make a significant contribution to the realization of LAM associated clinical features, diagnostic approaches, and its afterward treatments.

Immunohistochemistry of Janus Kinase 1 (JAK1) Expression in Vitiligo

BACKGROUND: Vitiligo is a chronic autoimmune disease in which the destruction of melanocytes causes white spots on the affected skin. Janus kinase (JAK) is a family of intracellular, non-receptor tyrosine kinases that transduce cytokine-mediated signals via the JAK–signal transducer and activator of transcription pathway. The aim of the present study is to explore the possible role of JAK1 in the pathogenesis of vitiligo using immunohistochemical methods. METHODS: The current study was conducted in a sample of 39 patients who presented with vitiligo and 22 healthy individuals who were age and sex matched as a control group. We used immunohistochemistry to evaluate JAK1 status (intensity and distribution) and assess the percentage of residual melanocytes using human melanoma black 45 (HMB45). RESULTS: Intense and diffuse JAK1 expression was significantly more likely to indicate vitiliginous skin compared to normal skin (p < .001). Strong and diffuse JAK1 expression was associated with short disease duration, female sex, and lower percentage of melanocytes (detected by HMB45) (p < .05). CONCLUSIONS: JAK1 may be involved in the pathogenesis of vitiligo, as indicated by intense and diffuse expression compared to control and association with lower percentage of melanocytes detected by HMB45 immunostaining.

Immunohistochemistry: sole tool in diagnosing a rare case of primary vaginal amelanotic melanoma

We report a rare case of vaginal amelanotic melanoma. Malignant melanomas are cutaneous and extracutaneous tumors that arise from embryological remnants of neural crest cells/melanocytes. Amelanotic melanomas at such rare locations can be misdiagnosed both clinically and radiologically. Therefore, histopathological examination and immunohistochemistry are mandatory for the diagnosis of these tumors. We diagnosed this case using histopathology and confirmed the diagnosis based on the presence of immunohistochemical markers human melanoma black 45 (HMB45) and S-100.

A Misdiagnosed Case of Anal Canal Malignant Melanoma: A Case Report.

Anal canal malignant melanoma is an uncommon malignancy. It is a highly aggressive tumor that tends to spread early in the course and present with distant metastasis. Due to the rarity of the condition, treatment is yet to be standardized. We report a case of a 47-y ear-old male patient who presented with the history of mass coming out of anus for 6 months, which was misdiagnosed as a case of hemorrhoids. Abdominoperineal resection was done based on tissue biopsy which suggested it to be a primary anal canal malignant melanoma. The diagnosis was later confirmed by histopathological and immunohistochemistry studies, which was strongly positive for HMB 45 AND Melan-A.

Perivascular Epithelioid Cell Tumor in the Stomach

Perivascular epithelioid cell tumors or PEComas can arise in any location in the body. However, a limited number of cases of gastric PEComa have been reported. We present two cases of gastric PEComas. The first case involved a 62-year-old woman who presented with a 4.2 cm gastric subepithelial mass in the prepyloric antrum, and the second case involved a 67-year-old man with a 5.0 cm mass slightly below the gastroesophageal junction. Microscopic examination revealed that both tumors were composed of perivascular epithelioid cells that were immunoreactive for melanocytic and smooth muscle markers. Prior to surgery, the clinical impression of both tumors was gastrointestinal stromal tumor (GIST), and the second case was erroneously diagnosed as GIST even after microscopic examination. Although gastric PEComa is a very rare neoplasm, it should be considered in the differential diagnosis of gastric submucosal lesions.

Hepatic perivascular epithelioid cell tumor (PEComa): a case report with a review of literatures

Hepatic perivascular epithelioid cell tumors (PEComas) are very rare. We report a primary hepatic PEComa with a review of the literature. A 56-year-old women presented with a nodular mass detected during the management of chronic renal failure and chronic hepatitis C. Diagnostic imaging studies suggested a nodular hepatocellular carcinoma in segment 5 of the liver. The patient underwent partial hepatectomy. A brown-colored expansile mass measuring 3.2×3.0 cm was relatively demarcated from the surrounding liver parenchyma. The tumor was mainly composed of epithelioid cells that were arranged in a trabecular growth pattern. Adipose tissue and thick-walled blood vessels were minimally identified. A small amount of extramedullary hematopoiesis was observed in the sinusoidal spaces between tumor cells. Tumor cells were diffusely immunoreactive for human melanoma black 45 (HMB45) and Melan A, focally immunoreactive for smooth muscle actin, but not for hepatocyte specific antigen (HSA).

Six Cases of Amelanotic Melanoma: Focused on the Difficulty of Early Differential Diagnosis / 대한피부과학회지

Amelanotic melanoma comprises only 1.8~8.1% of malignant melanomas, and is difficult to diagnose clinically due to the lack of the diagnostic evidence of clinical pigmentation. To our knowledge, it is rarely reported, and only 10 cases have been reported in the Korean dermatological literature. It presents rather conflicting features such as a pink or red macule, papule, plaque, or nodule mimicking various benign and malignant conditions; therefore, it is difficult to diagnose. We performed a review of six patients with amelanotic melanoma focusing on differential diagnosis, particularly at the time of the initial visit. Clinical impressions included pyogenic granuloma, dermatofibrosarcoma protuberans, eccrine poroma, epidermal cyst, keloid, pilomatricoma, and squamous cell carcinoma in addition to malignant melanoma. The biopsy specimens were consistent with malignant melanoma with little or no melanin pigment on hematoxylin and eosin and Fontana-Masson stains. Four of the six patients were positive for S-100 and HMB-45, but two patients were positive for S-100 only. We report these cases to remind clinicians of the necessity of including malignant melanoma in the differential diagnosis process when patients show poor and unpredictable responses to treatment after a clinical diagnosis of other benign and malignant conditions.

A Rare Case of Extracardiac Growing Angiomyolipoma Originating from the Interatrial Septum / 日本心臓血管外科学会雑誌

A 58-year-old man was admitted with a complaint of exertional chest discomfort. A mass, 53×55×66 mm in size, was detected in the transverse sinus of the pericardium, just cranial to the inter-atrial septum with enhanced chest CT. We performed resection of the tumor under cardiopulmonary bypass. Histopathological findings showed that the tumor was angiomyolipoma originated from the heart. Angiomyolipoma is a benign tumor, most frequently found in the kidney or liver and usually associated with tuberous sclerosis. Extra-cardiac growth of the cardiac angiomyolipoma is extremely rare, and only few have been reported previously.

Malignant Perivascular Epithelioid Cell Tumor (PEComa) Arising in the Omentum with Metastatic Peritoneal Seeding: A Case Report / 대한내과학회지

The World Health Organization (WHO) defines a perivascular epithelioid cell tumor (PEComa) as a mesenchymal neoplasia composed of perivascular epithelioid cells with characteristic morphological and immunohistochemical features. They are rarely malignant. Indeed, only a few cases have been reported in the English literature, and this is the first case of PEComa reported in Korea. A 64-year-old man presented with an abdominal mass and peritoneal seeding. The patient underwent mass excision with descending colon resection and anastomosis. The primary mass and peritoneal seeding was diagnosed as a PEComa histopathologically. Seven months later, he developed liver metastasis and aggravated peritoneal seeding. Here, we report a case of malignant PEComa of the omentum.

Unilateral Pigmented Extramammary Paget's Disease of the Axilla Associated with a Benign Mole: A Case Study and a Review of Literature

Pigmented extramammary Paget's disease (PEMPD) is an uncommon intraepithelial adenocarcinoma and a rare variant of Paget's disease affecting skin that is rich in apocrine sweat glands such as the axilla, perianal region and vulva. It most commonly occurs in postmenopausal women and presents as a superficial pigmented scaly macule, mimicking a melanocytic lesion. The histological presentation is adenocarcinoma in situ with an increased number of melanocytes scattered between the Paget's cells. Therefore, PEMPD may be misdiagnosed as a melanocytic tumour both clinically and histologically. The tumour cells are usually positive for cytokeratin 7, epithelial membrane antigen, Cam 5.2, HER2, and mucicarmine stain while S100 and human melanoma black-45 highlight the processes of reactive dendritic cells. The association between Paget's cells and intratumoural reactive melanocytes is still unclear. We report our first case of PEMPD associated with an intradermal naevus involving the axilla in a 63-year-old woman.

Conventional renal cell carcinoma with renal capsular leiomyoma: A diagnostic dilemma.

Primary renal leiomyomas are very rare benign tumors of the kidney, arising from smooth muscle cells of the renal capsule, pelvis or blood vessels. Simultaneous occurrence of a leiomyoma with conventional renal cell carcinoma (RCC) in the same kidney is an extremely rare incidence. Herein we describe a case, which to the best of our knowledge is the second reported case in the English literature. This 70-year-old female presented in surgical out-patient department with the complaints of hematuria and abdominal pain. Subsequently, on computed tomography a multifocal mass was noted in the right kidney, measuring 4.5 cm × 3 cm × 2 cm and 1 cm × 0.5 cm × 0.5 cm respectively. A radical nephrectomy was performed with the clinical diagnosis of a multifocal RCC. Histopathological examination revealed a conventional RCC in the larger nodule, whereas the smaller nodule showed a sub capsular leiomyoma, which was immune-positive for smooth muscle actin and HMB45. In the index case, radiology could not differentiate between the RCC and leiomyoma. Apart from being a radiological diagnostic dilemma, rare HMB45 immunostain positivity in capsular leiomyoma may create diagnostic dilemma for histopathologists too. Sole HMB45 positivity should not distract one to diagnose this lesion as an angiomyolipoma, unless the other components are seen.

Retroperitoneal sclerosing PEComa with melanin pigmentation and granulomatous inflammation-A rare association within an uncommon tumor.

PEComa, defined as a perivascular epithelioid cell tumor, displays a wide clinicopathological spectrum. Lately, a sclerosing PEComa has been identified as its distinct variant, but with limited documentation, in view of its rarity. Herein, we describe an uncommon case of a 53-year-old lady, who was referred to us with pain abdomen. Radiological imaging disclosed a well-defined, hypodense retroperitoneal mass. The excised tumor was a round, encapsulated soft tissue mass measuring 7 cm with a tan-brown cut surface. Microscopy showed uniform, epithelioid cells with clear cytoplasm, focal melanin pigmentation and mild nuclear atypia, arranged in sheets and nests around capillary-sized vessels in a dense sclerotic stroma. Additionally, co-existing epithelioid granulomas were noted. On immunohistochemistry (IHC), tumor cells were diffusely positive for HMB45; focally for desmin and smooth muscle actin (SMA), while negative for EMA, CD10, S100-P, Melan A, CD34, AMACR and CK MNF116. This case reinforces sclerosing PEComa as an uncommon, but a distinct clinicopathological entity and exemplifies diagnostic challenge associated with it; necessitating application of IHC markers for its correct identification. Presence of melanin pigment and granulomatous inflammation in the present tumor constitute as novel histopathological findings in a sclerosing PEComa.

Hepatic Angiomyolipoma with Variable Histologic Features: 8 Cases Resembling Hepatocellular Carcinoma or Inflammatory Pseudotumor / 대한소화기학회지

BACKGROUND/AIMS: Hepatic angiomyolipoma (AML) is a rare mesenchymal tumor of the liver and demonstrates a marked histologic diversity. HMB-45 is a promising immunomarker for this tumor and especially helpful to diagnosis of some AMLs with unusual morphology. The purpose of this study was to better define the variable histologic feature of hepatic AML. METHODS: Eight hepatic AMLs were examined, and all of that were resection specimens. The diagnosis was confirmed by the presence of HMB-45 positive cells. Median age was 41.5 years old, and mean size of tumor was 8.94 cm. RESULTS: Conventional mixed type was 5 cases which showed myomatous, angiomatous and lipomatous component, and 3 cases were myomatous predominant. Variable patterns including spider web cell morphology, solid sheet-like and trabecular pattern were identified on myomatous component and variable amount and patterns of inflammatory cell infiltration was identified. CONCLUSIONS: With only histologic features, it is difficult to distinguish hepatic AML from other hepatic tumor including hepatocellular carcinoma or inflammatory pseudotumor. A correct diagnosis of hepatic AML is possible by a close histologic examination with immunohistochemical stainings such as HMB-45 which is important to patient's prognosis.

Melanotic Choroid Plexus Carcinoma of the Posterior Fossa

BACKGROUND: The pigmented or melanotic variant of choroid plexus carcinoma is very rarely encountered. CASE REPORT: We report herein a case of melanotic or pigmented choroid plexus carcinoma in the posterior fossa of an 11-year-old female. CONCLUSIONS: A histopathological study supported by immunohistochemistry helped the authors to diagnose this rare entity. How to differentiate this tumor from pigmented papillary medulloblastoma, cerebellar papillary ependymoma, and metastatic malignant melanoma is discussed.

Nodular amelanotic melanoma.

We report a case of 65-year-old male patient who presented with multiple erythematous papules coalescing to form a nodular mass over posterior aspect of right thigh of six months duration. His general and systemic examinations were within normal range except for right inguinal lymphadenopathy. Biopsy from the lesion was done, which showed diffuse infiltrate of nests of atypical melanocytes extending upto reticular dermis. Malignant cells were positive for S100 and human melanin black 45(HMB 45). Hence, a diagnosis of amelanotic melanoma (AM) - Clarke level IV and TNM stage III was reached. MRI of involved leg showed fungating soft tissue mass in the posterolateral aspect of right thigh and metastatic right inguinal adenopathy. Fine needle aspiration cytology (FNAC) from the right inguinal nodes confirmed metastasis of melanoma. The patient was referred to oncosurgery department for further management.

Malignant melanoma of the mandibular gingiva: A rare occurrence.

Primary mucosal malignant melanoma of the oral cavity is a rare tumor. It accounts for only 0.2-8% of all malignant melanomas. This malignancy commonly affects male subjects and is more frequently seen on the hard palate and maxillary gingiva. The peak age for diagnosis of oral melanoma is between 55 and 65 years. A biopsy is required to establish a diagnosis. Ablative surgery with tumor-free margins remains the treatment of choice. It has a much poorer prognosis than its counterpart on the skin. Here, we present a case of malignant melanoma of the mandibular lingual gingiva in a 55-year-old male patient. Immunohistochemistry and special stains were conducted for confirmatory diagnosis.

Hepatic angiomyolipoma: a report of 13 cases / 中华肝胆外科杂志

Objective To investigate the clinical features and prognosis of hepatic angiomyolipoma(HAML). Methods Clinical data of 13 patients with operatively confirmed HAML treated in our hospital were retrospectively analyzed. Results HAML was usually asymptomatic and the imaging features varied. Only 1 case was correctly diagnosed before operation. HMB45 positive staining was the pathologic characteristic of HAML. Conclusion HAML can be easily misdiagnosed, should be properly treated by surgery and has a good prognosis.

Primary amelanotic melanoma of the cervix: case report with review of literature / 부인종양

Primary malignant melanoma of the uterine cervix is a rare neoplasm with poor prognosis. It may be misdiagnosed especially when amelanotic, in which case immunohistochemistry is useful in reaching the diagnosis. We present one such case of a 65-year-old postmenopausal female patient presenting with bleeding per vaginum. Speculum examination revealed an ulcero-proliferative growth involving the cervix. On histopathological examination it was originally suspected to be a poorly differentiated carcinoma or a non-epithelial malignant tumor, but was subsequently correctly diagnosed by immunohistochemical staining with the HMB-45 antibody and S-100 protein.