Human Pathology: Case Reports最新文献

Anaplastic thyroid carcinoma (ATC), one of the most aggressive subtypes of thyroid cancer, is composed of undifferentiated thyroid follicular cells demonstrating ultrastructural or immunohistochemical features of epithelial differentiation. Frequently, these tumors can be shown to have originated from papillary thyroid carcinoma (PTC). ATC exists on a morphologic spectrum composed of three main patterns: spindle cell (sarcomatoid), giant cell, and epithelial (squamous) components.

Here we discuss two cases in which patients presented with upper airway symptoms and subsequently, a laryngotracheal lesion was detected by imaging studies and bronchoscopy. In each case, biopsies taken from these lesions showed invasive squamous cell carcinoma; however, both patients had previously undergone total thyroidectomy for PTC, and immunohistochemical studies revealed that the biopsied tumor cells were of thyroid origin. Furthermore, the cells harbored the BRAF^V600E mutation, suggesting anaplastic transformation from PTC.

Invasion into the larynx or trachea is a known complication of aggressive forms of thyroid cancer. However, laryngotracheal presentation of anaplastic thyroid carcinoma with squamous differentiation can easily be misdiagnosed as a primary squamous cell carcinoma. Immunohistochemical studies for thyroid lineage markers (e.g. PAX8) as well as squamous markers (e.g. p40, p63) should be performed, and if there is a known history of PTC, mutation analysis for BRAF^V600E can support the diagnosis via molecular testing or immunohistochemistry.

Objectives

To report the postmortem findings of a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) positive individual who died in Lagos (Nigeria) in June 2020 and to investigate the cause, pathogenesis as well as pathological changes noticed during the examination.

Methods

Complete postmortem examination was performed according to standard procedures in a regular autopsy suite using personal protective equipment including N95 masks, goggles and disposable gowns. The diagnosis of coronavirus disease 2019 (COVID-19) was confirmed by real-time reverse transcription polymerase chain reaction (RT-PCR) testing on postmortem nasopharyngeal swabs.

Results

A 47-year-old man with a medical history of well controlled hypertension and dyslipidaemia died after long hours of transportation for medical care in a hospital in Lagos. He tested positive for SARS-CoV-2 on ante- and postmortem nasopharyngeal swabs. Autopsy revealed pneumonia with diffuse alveolar damage, disseminated intravascular coagulopathy and hypovolaemic shock.

Conclusions

Autopsy can be performed on decedents who died from or with SARS-CoV-2 infection in a low resource environment such as ours. A standard autopsy room was used while deploying recommended infection prevention control and regular decontamination. The clinical details, autopsy findings such as diffuse alveolar damage and airway inflammation were consistent with a COVID-19 related pathology. While the decedent had ‘controlled’ co-morbidity, he succumbed to multi-organ failure occasioned by shock and disseminated intravascular coagulopathy.

SMARCA4-deficient thoracic tumor (SMARCA4-DTT) is a relatively new pathological entity with highly aggressive characteristics. With mass lesions developing in the thoracic region, patients tend to complain of chest symptoms, such as dyspnea or chest pain. Here, we encountered a rare case of SMARCA4-DTT presenting to the otolaryngology clinic with painful throat and diagnosed by palatal tonsil biopsy.

A 47-year-old male patient with heavy smoking habit presented to a nearby clinic due to sore throat occurring a few days before presentation. Antibiotic therapy was prescribed for the treatment of acute tonsillitis. However, the pain exacerbated, and mass lesion in the submandibular region started to develop. The patient was referred to our department for detailed examination due to suspected pharyngeal malignancy. Right tonsil biopsy was performed, and the patient was diagnosed with SMARCA4-deficient tumor. Computed tomography illustrated compressive mass lesion in the mediastinum and multiple swelling of systemic lymph nodes. Although radiotherapy and chemotherapy were performed, the lesion rapidly progressed, and brain metastasis also occurred. The patient followed a poor disease course and died 91 days after the first symptom.

SMARCA4-deficient tumor has been reported in other sites, such as ovary, uterus, and gastrointestinal tract. The purpose of the present article is to make literature review on clinicopathological characteristics of SMARCA4-deficient tumors in various sites while reporting the rare presentation of SMARCA4-DTT.

Background

Cribriform adenocarcinoma of salivary glands (CASG) is a rare, predominantly minor salivary gland tumor first described in 1999. Because the tumor shares morphologic and molecular features with polymorphous adenocarcinoma (PAC), in 2017, the World Health Organization (WHO) included CASG within the spectrum of PAC. Almost 75% of CASG harbor molecular alterations in the PRKD (Protein kinase D) gene family, and some cases show ARID1A (AT-rich interaction domain 1A)-PRKD1 or DDX3X (DEAD-Box Helicase 3 X-Linked)-PRKD1 fusions.

Case presentation

A 39-year-old man presented with headache and painless right cheek mass of two years duration. Imaging showed a well-circumscribed, lobulated 1.7-centimeter mass located in the superficial lobe of the right parotid gland. Fine needle aspiration (FNA) of the mass revealed a “salivary gland neoplasm of uncertain malignant potential” (SUMP). Histopathology and immunohistochemical features of the resected tumor showed a primary salivary gland neoplasm with perineural invasion suggestive of cribriform adenocarcinoma of the salivary glands (CASG). Whole exome sequencing (WES) and transcriptome sequencing (RNAseq) of the tumor revealed a novel, intrachromosomal gene fusion: KTN1 (Kinectin1)-PRKD1. Sanger sequencing and Florescent insitu hybridization (FISH) break apart probe results subsequently confirmed the presence of the fusion. The patient recovered from surgery without complications.

Conclusion

We report a novel fusion KTN1-PRKD1 in Cribriform Adenocarcinoma of the Salivary Glands located in the parotid gland. Importantly, this KTN1 fusion partner may account for other reports of intrachromosomal fusions in CASG in which the PRKD1 gene partner was not identified.

Cutaneous T-cell lymphoma (CTCL) presenting as mycosis fungoides is typically localized to the skin and occasional draining lymph nodes. We present a 46-year-old man with refractory CTCL status-post allogeneic stem cell transplant who was biopsied for diarrhea and abdominal pain. These gastrointestinal biopsies revealed not only graft-versus-host-disease but also a clonal atypical lymphoid infiltrate with the same morphology and immunophenotype as the patient’s known CTCL. We discuss the differential diagnosis of CTCL metastatic to the intestinal mucosa versus post-transplant lymphoproliferative disorder and present a review of the literature. This case demonstrates challenging diagnostic workups in limited tissue samples as well as critical clinical implications.

Two rare cases of large cell neuroblastoma (LCN) are reported. Case 1 (8-year-old male) showed the appearance of Neuroblastoma, poorly differentiated subtype with a high MKI (Mitosis-Karyorrhexis Index) and Case 2 (7-year-old male) was Neuroblastoma, undifferentiated subtype with a low MKI. Both cases were classified into the Unfavorable Histology Group according to the International Neuroblastoma Pathology Classification and their tumors were characteristically composed of neuroblastic cells with enlarged and often pale or vacuolated nuclei containing one or few prominent nucleoli. While LCN is a phenotypical variant of MYC-driven neuroblastoma overexpressing MYC-family protein, the two tumors presented in this report had different molecular characteristics: One had n-MYC oncogene amplification with n-MYC protein overexpression (Case 1), and the other had c-MYC protein overexpression without genomic amplification (Case 2). It was also noted that the tumor cells in Case 2 demonstrated “aberrant” desmin expression by immunostaining.

Introduction

Rosai-Dorfman disease (RDD) is a rare, idiopathic, proliferative disorder of histiocytes usually involving head-neck lymph nodes. It can also involve extra nodal sites like skin, nasal sinuses, and soft tissue. It rarely affects the breast.

Case presentation

We present three unusual case scenarios of breast RDD. One presented with breast lump, clinico-radiologically mimicking early breast cancer. The second case was thought to be de-novo metastatic breast cancer, but was found to have disseminated RDD of breast, lymph nodes and bones. The third patient was that of cervical lymphadenopathy in a breast cancer survivor masquerading as recurrence. In all 3, histopathology showing emperipolesis and immunohistochemical staining with S100 clinched the diagnosis.

Discussion

The diagnosis of RDD is made by histopathology. The classic histological picture consists of a lymphoid rich associated infiltrate, atypical nuclei of the histiocytes and lack of fat necrosis or acute inflammatory cells. These histiocytes typically stain positive with S100 and CD168 on immunohistochemistry. Hence, an excision biopsy is often necessary, and mostly the only treatment needed. However, if the disease is disseminated or has massive lymphadenopathy, a course of oral steroids or chemotherapy is indicated.

Conclusion

RDD of the breast usually has an indolent, benign, and non-aggressive course that requires minimum treatment. A high index of suspicion and accurate histopathological diagnosis is utmost important for proper management.

Cap polyposis is a rare, non-neoplastic disease characterized by multiple inflammatory polyps that are covered by a “cap” of fibrinopurulent granulation tissue and in most cases are located between the distal colon and the rectum. Patients usually present with bloody diarrhea, mucoid stools, and constipation. Endoscopically, mucosal polypoid structures are seen in the colon covered with a characteristic superficial, adherent white “cap” with normal intervening mucosa. Cap polyposis affects patients over a wide age range and, in rare instances, may also affect children. We report 2 cases of cap polyposis in the descending and rectosigmoid colon of a 6-year-old girl and in the rectosigmoid colon of a 61-year-old woman who have been followed for 8 and 6 years, respectively. Initial clinical examination and imaging, including computed tomography and colonoscopy revealed changes suspicious for inflammatory bowel disease and malignancy. Subsequent and repeated histopathological examinations however, revealed cap polyposis without definitive evidence of infection, chronic mucosal architectural changes, mucosal prolapse or dysplasia. We believe that this the first report of a pediatric patient with diffuse involvement of the descending and rectosigmoid colon by multiple inflammatory cap polyps mimicking inflammatory bowel disease. Furthermore, the unusual clinical presentation in both patients made the final diagnosis of cap polyposis challenging. When typical morphologic features of inflammatory-type polyposis present without evidence of mucosal prolapse, inflammatory bowel disease, inflammation or malignancy, a high index of suspicion for cap polyposis is warranted for timely recognition and treatment.

Background

Since the first report in 2008 of cases of anaplastic lymphoma kinase (ALK)-positive histiocytosis, originally described as a systemic, self-limiting disease in infants, the range of ALK-positive histiocytosis has been expanded to include localized diseases in older children and adults.

Case presentation

We present the case of an 18-year-old woman with a periumbilical painless mass for 5 months who underwent resection of the mass. Pathological examination showed that the tumour consisted predominantly of fascicular to storiform growth of nonatypical spindle cells admixed with lymphocytic infiltrates. The tumour spindle cells were diffusely positive for CD68, CD163 and ALK. Further molecular tests revealed an ALK gene fusion with Kinesin Family Member 5B (KIF5B) (E24)-ALK (E20), confirming ALK-positive histiocytosis. Follow-up at one and a half years after resection showed no tumour recurrence.

Conclusion

Remission of ALK-positive histiocytosis in local lesions can be achieved by complete resection, and clinical follow-up shows a favourable prognosis.

Donor-derived myeloid sarcoma (DDMS) is a rare complication which occurs when donor stem cells undergo leukemic transformation. We report here two cases of DDMS following successful allogenic hematopoietic stem cell transplant (allo-HSCT) from HLA-identical, sex-mismatched sibling donors. Both were males in their fourth decade of life and originally diagnosed in 2012 with acute myeloid leukemia (AML) with t(6;11)(q27;q23) and AML with myelodysplasia-related changes (AML-MRC), respectively. They went onto allo-HSCT from their respective haploidentical sisters as donors and achieved complete engraftment in 2014. Both were in remission until 2019 when they were diagnosed with clinical relapse of AML in the setting of DDMS, one presenting in bilateral tibiae and the other in the testis. Verifying donor origin in AML relapse is critical as transformed donor cells may have different genetic alterations and behaviors from initial AML. We reviewed the literature of donor derived myeloid sarcoma and discussed the pathogenesis of this rare late complication of HSCT.