Pilomatricomas can be confidently diagnosed cytologically due to their characteristic cytomorphological features. However, these lesions are rarely encountered by cytopathologists and thus pose a diagnostic dilemma to even experienced individuals, especially when the lesions are focally sampled. We describe two cases of histologically confirmed pilomatricoma. The first case is of a 13-year-old boy with posterior cervical ‘lymphadenopathy’, and the second one is of a 12-year-old girl with a lower cheek swelling. Both aspirates comprised predominantly atypical basal-like cells, with prominent nucleoli. ‘Ghost cells’ were readily identified by cell block in case two, but cell block in case one yielded no diagnostic material. In case two, pilomatricoma was accurately diagnosed pre-operatively. A cytological suspicion of a neoplastic process was raised in case one. Despite being diagnostically challenging, pilomatricoma can be diagnosed with careful observation of two unique cytological features of the lesions: (1) pathognomonic ‘ghost cells’ and (2) irregular, saw-toothed, loosely cohesive basaloid cells, with prominent nucleoli. The role of thorough sampling of the lesion, with multiple passes of various sites, cannot be overemphasized.

Small cell lung carcinoma (SCLC) commonly metastasizes to distant organs. However, metastasis to the pancreas is not a common event. Moreover, obstructive jaundice as a first clinical presentation of SCLC is extremely unusual. This case reports a 51-year-old male with SCLC, manifesting with obstructive jaundice as the initial clinical presentation. Endoscopic retrograde cholangiopancreatograghy (ERCP) and abdominal computed tomography (CT) scan showed a mass at the head of the pancreas. The patient underwent pancreatoduodenectomy (Whipple procedure). Histopathology revealed a chromogranin- A-positive poorly-differentiated neuroendocrine carcinoma of the pancreas. No imaging study of the lung was performed before surgery. A few months later, a follow-up CT revealed unilateral lung nodules with ipsilateral hilar nodes. A lung biopsy was done and histopathology reported a TTF- 1-positive, chromogranin A-positive, small cell carcinoma of the lung. On review, the pancreatic tumour was also TTF-1-positive. He was then treated with combination chemotherapy (cisplatin, etoposide). These findings highlight that presentation of a mass at the head of pancreas could be a manifestation of a metastatic tumour from elsewhere such as the lung, and thorough investigations should be performed before metastases can be ruled out.

To assess the diagnostic utility of glypican-3 (GPC-3) in comparison to Hep Par 1 in the diagnosis of liver tumours, a cross-sectional study involving 66 resected liver tumours were tested for the protein expression of these markers by immunohistochemistry using monoclonal antibodies. Of the 66 cases, 26 (39.4%) were hepatocellular carcinoma (HCC), 4 (6.1%) were intrahepatic cholangiocarcinoma and 36 (54.5%) were metastatic tumours. Hep Par 1 and GPC-3 expressions in HCC were 24/26 (92.3%) and 19/26 (73.1%) respectively. In contrast, of non-HCC cases, only 2/40 cases (5.0%) expressed Hep Par 1, including a metastatic colorectal adenocarcinoma and a metastatic gastric adenocarcinoma. GPC-3 was expressed in 3/40 cases (7.5%), i.e. a metastatic adenocarcinoma of unknown origin, a metastatic gastric adenocarcinoma and an intrahepatic cholangiocarcinoma. The sensitivity and specificity for Hep Par 1 were 92.3% and 95% respectively while that of GPC-3 was 73.1% and 92.5% respectively. GPC-3 is a useful marker in the diagnosis of HCC. However it is not superior to Hep Par 1 in its sensitivity and specificity. We recommend that it is utilized together with Hep Par 1 as a panel in the diagnosis of HCC.

Follicular lymphoma is characterised by the t(14;18)(q32;q21) chromosomal translocation causing BCL2 protein overexpression. A proportion of follicular lymphomas do not carry the t(14;18) translocation and lacked BCL2 protein expression. We describe a case of a BCL2 protein- and t(14;18)-negative follicular lymphoma that caused diagnostic difficulty. The usefulness of several immunomarkers including Ki67, CD79a and CD21 in aiding the diagnosis is discussed. The patient is a 51-year-old male who presented with gradually enlarging lymphadenopathy. Histopathological examination of the lymph node showed complete architectural effacement by neoplastic follicles containing expanded CD21-positive follicular dendritic cell meshwork. The neoplastic cells expressed pan-B cell markers (CD20, CD79a) and germinal centre marker (BCL6) but not BCL2 and CD10. Of interest are the staining patterns of Ki67 and CD79a. We observed that the Ki67- positive proliferating cells were evenly distributed within the neoplastic follicles without zonation. In addition, CD79a was homogeneously strong within the neoplastic follicles. These staining patterns were distinctly different from that observed in reactive lymphoid follicles. Fluorescent insitu hybridisation (FISH) analysis however showed absence of BCL2 gene rearrangement. Despite the atypical immunophenotype and lack of BCL2 gene rearrangement, the diagnosis of follicular lymphoma was made based on careful observation of the morphology as well as immunoarchitecture of the Ki67, CD79a and CD21 markers.

Most breast cancer recurrences occur in the surgical scars or within other quadrants of the same breast. Isolated tumour recurrence occurring in the nipple after breast-conserving surgery and radiotherapy is extremely unusual. The reason for this is unknown, but is speculated to be due to involved surgical margins or an occult involvement of the nipple–areolar complex in a breast cancer of the same breast. We present a case of a 44-year-old Indian woman who had recurrent tumour over her right nipple after an ipsilateral breast-conserving surgery that was followed by adjuvant chemotherapy and radiotherapy. There was no typical malignancy features from the mammogram. However, histopathological study confirmed a malignant growth that infiltrated into the dermis and the underneath breast tissue. Completion mastectomy was then performed and the patient was later treated with Taxane-based chemotherapy. Nipple recurrence after breast-conserving surgery and adjuvant radiotherapy may be confused with other nipple conditions such as Paget’s disease of the breast. Comprehensive assessments, which include mammogram and biopsy, have proved that such recurrence do occur, as presented in this case. This warrants a specific management strategy.

Metastatic renal cell carcinoma (RCC) presenting with multiple deposits in the head and neck region is unusual. It is not uncommon for a RCC to metastasise to a distant site after years of a tumour-free period, but most of it would be expected to have a single site of deposit. We report a rare case of a patient who had a nephrectomy 10 years earlier for RCC and presented with tumours in the frontal sinus and posterior pharyngeal wall. Radiological imaging and histology confirmed metastatic RCC at both sites.

Myeloid sarcoma (MS) is a rare extramedullary myeloid tumour. It has been reported in various sites, including lymph node, bone, skin, soft tissue, various organs and the CNS. It may precede or occur concurrently with acute myeloid leukemia. Urinary bladder involvement is extremely uncommon. We report a 70-year-old female who had MS of the urinary bladder, presented with frank and persistent hematuria associated with lower abdominal pain. She subsequently had tumour seeding in the abdominal skin via percutaneous suprapubic catheter. Tumours from both the urinary bladder and skin showed immature cells that were immunoreactive toward LCA (focal), MPO (strong), CD99 (weak) and CD117 (weak). Summary of cases in the literature is presented. The potential of its misdiagnosis and the useful markers for the diagnosis of MS are discussed