Multifocal EBV-associated smooth muscle tumors in a patient with cytomegalovirus infection after liver transplantation: a case report from Shiraz, Iran

Introduction Immunodeficient patients, including the recipients of solid organs, exhibit an increase in the incidence of neoplasms. Post-transplant smooth muscle tumor (PTSMT) is a distinct and infrequent entity of these groups of neoplasms. Epstein–Barr virus (EBV) is considered to be involved in the etiology of this neoplasm. Case report A 28-year-old man who underwent liver transplantation presented with abdominal pain and diarrhea for several months. He had a history of resistant systemic cytomegalovirus (CMV) infection after transplantation. Radiologic evaluation and colonoscopy revealed multiple liver, spleen, lung, and colon lesions. Microscopic assessment of colon and liver lesions using IHC study were in favor of spindle cell proliferation with mild atypia and a mild increase in mitotic rate without any necrosis, with features of smooth muscle tumor. Considering the transplantation history, EBER chromogenic in situ hybridization (CISH) study on paraffin blocks was requested, which demonstrated EBV RNA in tumor cell nuclei, suggesting EBV-associated smooth muscle tumor. In addition, PCR for CMV on paraffin blocks was positive. PCR for EBV and CMV viremia were negative. The dosage of immunosuppressive agents was reduced, and currently, he is being followed, with slow expansion in the size of the lesions. Conclusion Although the incidence of post-transplant smooth muscle tumors (PTSMTs) is low, it should be remained in the differential diagnosis in post-transplantation patients, especially dealing with multifocal tumors. As strong stimulant for smooth muscle tumors, close follow-up and screening for EBV and CMV infection and early treatment at the time of diagnosis are recommended to avoid these virus-induced tumors.

Schwannoma of the Appendix Orifice

Schwannomas are rare mesenchymal tumors. They are usually diagnosed incidentally during endoscopic or diagnostic imaging for another reason. Malignant transformation is rare. In this case report, we present an incidental schwannoma protruding through the appendiceal orifice diagnosed during endoscopy. A healthy 56-year-old female underwent a surveillance colonoscopy for family history of colorectal cancer. A prominent and edematous appendiceal orifice was noted, and the area was aggressively biopsied. Histopathological assessment revealed a benign schwannoma. Computerized topography was unremarkable. Subsequently, the patient underwent a right hemicolectomy. Patient is scheduled to undergo routine surveillance in three years. Grossly, schwannomas are white, encapsulated, and well-circumscribed lesions that stain strongly positive for S100, GFAP, and CD57. Histologically, schwannomas demonstrate spindle cell proliferation. Several imaging modalities have been utilized in the diagnosis and management of mesenchymal neoplasms. Despite the benign nature of the diagnosis, complete surgical resection with clear margins remains the gold standard management strategy. Our case highlights the presence of a relatively uncommon tumor in an unusual anatomical location.

Infantile Systemic Hyalinosis Presenting as Pseudo-Paralysis in Infancy: Study of Six Cases

Infantile systemic hyalinosis is a very rare fatal autosomal recessive genetic disorder with a mutation in capillary morphogenesis gene-2-CMG2/Human anthrax toxin-2 ANTXR2 resulting in spindle cell proliferation, altered collagen metabolism along with extensive deposition of hyaline material in the skin and several tissues. To date only a few cases have been reported in the literature, hence we reported this series. This study is a retrospective chart review of infants diagnosed with infantile systemic hyalinosis from January 2015 through December 2020 at a tertiary care children's hospital in South India. The mean age of presentation was 9.4 months, with a male to female ratio of 1:5. All children were born of consanguineous marriage except one child. All children had symptoms at birth, painful limb movements, multiple joint stiffness, gingival thickening, skin lesions around perianal, perioral areas, and frog-like position. Three (50%) children had stiff skin. Routine tests including complete blood count, liver function test, renal function test, creatine phosphokinase, nerve conduction studies, and metabolic tests were normal in all children. Skin biopsy showed hyalinized collagenous tissue in the dermis. Genetic study results of two cases revealed pathogenic variants in ANTXR2 gene. Infantile systemic hyalinosis should be considered in infants presenting with painful limb movements. The diagnosis helped in avoiding unnecessary investigations and prognostications. The genetic information from proband mutation helped in prenatal diagnosis in two families.

Carcinoma with Triphasic Differentiation Arising from Inverted Papilloma in Sinonasal Sinus: A Rare Case with Molecular Characterization

Small cell neuroendocrine carcinoma (SNEC) is a rare subset of tumors in the sinonasal sinus. Combined tumors are exceedingly rare. Here, we describe a 65-year-old male with a mixed tumor of SNEC and sarcomatoid carcinoma arising in an inverted papilloma, containing squamous cell carcinoma in situ (SqCCis) in the sinonasal sinus. We evaluated the molecular characteristics of the two separate carcinoma components using next-generation sequencing. The patient presented with a nasal obstruction. Computed tomography showed a mass infiltrating the right ethmoid and maxillary sinuses. An excisional biopsy was performed. The tumor was found to have three morphologically distinct components. The first was SqCCis arising in an inverted papilloma, which was positive for cytokeratin and P40. The second consisted of nests of densely packed small round cells representing SNEC-positive neuroendocrine markers. The third was a solid sheet of anaplastic spindle cell proliferation, which was negative for the above markers. Oncogenic mutations such as FBXW7, TP53, and EGFR were detected in both SNEC and sarcomatoid carcinoma, and MYCL amplification was observed only in the SNEC component. This case highlights an extremely rare presentation of combined SNEC and sarcomatoid carcinoma arising from an inverted papilloma in the sinonasal sinus.

The Most Common Mistake in Laryngeal Pathology and How to Avoid it

Upper aerodigestive tract (UADT) spindle cell squamous carcinoma (SCSC), also known as sarcomatoid carcinoma, is a high-grade subtype of conventional squamous cell carcinoma (SCC) that is histologically characterized by a combination of differentiated SCC in the form of intraepithelial dysplasia and/or invasive differentiated SCC, and the presence of an invasive (submucosal) undifferentiated malignant spindle-shaped and pleomorphic (epithelioid) cell component. Typically, SCSC presents as a superficial polypoid mass not infrequently with surface ulceration precluding identification of an intraepithelial dysplasia. Further, in many cases an invasive differentiated SCC is not identified. Adding to the complexity in such cases, is that immunohistochemical staining in a significant minority of cases is negative for epithelial-related markers but often the cells express mesenchymal-related markers. In such cases, differentiating SCSC from a reactive (benign) spindle cell proliferation or a mucosal-based sarcoma can be problematic, with treatment implications. Herein, we detail the clinical and pathologic features of laryngeal SCSC and discuss the rationale for diagnosing a carcinoma and avoiding a diagnosis of sarcoma. In our experience, such cases represent one of the more common mistakes made in laryngeal pathology. Yet, virtually all such lesions are SCSCs. The treatment and prognosis relies on the accuracy of this distinction.

Solitary Fibrous Tumor of the External Auditory Canal

Solitary fibrous tumors (SFTs) originating from the external auditory canal are uncommon; only few cases have been reported in the literature. In this article, we report a case of a 35-year-old man who presented with a 6-month history of a gradual swelling in the entrance of the left external auditory meatus associated with hearing loss. The tumor was surgically removed, and histological examination showed spindle-cell proliferation with a collagenous stroma. Immunohistochemically, the tumor cells were positive for CD34 confirming the diagnosis of an SFT. Although SFTs are benign, complications such as relapses and metastasis after excision were reported. Thus, a careful and long follow-up is recommended.

Metastatic melanoma presenting as a malignant peripheral nerve sheath tumour

This is a report of a metastatic melanoma presenting clinically as a soft tissue mass and histologically being diagnosed as a malignant peripheral nerve sheath tumour. In this case the metastatic melanoma was preceded by a primary cutaneous melanoma in a similar anatomical region. Histologically the tumour was characterised by a malignant-appearing Spindle cell proliferation, arranged in fascicules. There was no evidence of connection to a nerve, co-existent neurofibroma or stigmata of neurofibromatosis. This presentation is only infrequently mentioned in the literature and heterogeneity can make clinical and histological diagnosis of metastatic melanoma problematic. It can easily be misinterpreted without effective clinico-histological correlation, making a good working relationship between Clinician and Histopathologist essential for correct diagnosis.

Pyogenic granuloma-like Kaposi sarcoma: Case report and review of literature

Pyogenic granuloma-like Kaposi sarcoma (PGLKS) is an uncommon variant of Kaposi sarcoma (KS), which mimics benign pyogenic granuloma both clinically and histologically. We report a case of PGLKS of the toe occurring in a HIV-positive individual. It presented as a 2cm skin swelling of 2 weeks’ duration which was clinically felt to be a pyogenic granuloma. Histopathological examination revealed a polypoid atypical vascular lesion with overlying peripheral epidermal collarette. Spindle cell proliferation typically seen in KS was also identified, which was positive for human herpesvirus 8 (HHV8) by immunohistochemistry, confirming the diagnosis of PGLKS. Upon review of the literature, our case is the 29th case of PGLKS reported to date, and only the sixth in Asian population. Particular attention to histomorphology, and demonstration of HHV8 in lesional tissue will aid accurate diagnosis of this rare entity.

Pyogenic granuloma-like Kaposi sarcoma presenting in an HIV-negative man who has sex with men

A 36-year-old immunocompetent man who have sex with men first presented to the plastics team with an ulcerating lesion on his left first toe. The lesion was suggestive of pyogenic granuloma (PG) clinically and histologically. Two years later, the same patient presented to the dermatology clinic with a new erythematous lesion with intermittent bleeding on the left second toe. Clinically, this lesion was suggestive of another PG. However, the histology of the skin curettage revealed part of a PG merging with an atypical spindle cell proliferation with characteristic ‘sieve-like’ appearance in keeping with Kaposi sarcoma. This was confirmed with human herpesvirus-8 immunohistochemistry staining. PG-like Kaposi sarcoma is an uncommon variant of Kaposi sarcoma. Often not considered clinically or histologically, a deep skin biopsy is essential to establish the right diagnosis. Our case highlights the need to consider Kaposi sarcoma as a differential diagnosis in all patients, including HIV-negative individuals, presenting with PG-like lesions.