BACKGROUND: Pilomatrixoma (pilomatrixoma, calcifying epithelioma of Malherbe) is a relatively uncommon, benign neoplasm arising from the skin adnexa. The tumor can cause diagnostic difficulty not only for the clinician but also for the cytologist.
CASE: A 62-year-old woman presented with a right submandibular swelling of 4 months' duration. The clinical findings were highly suspicious for malignancy. A fine needle aspiration biopsy was performed. Three preliminary differential diagnoses were offered: mucoepidermoid carcinoma of the submandibular salivary gland, squamous cell carcinomatous deposit in a submandibular lymph node and calcifying odontogenic tumor. Computed tomography demonstrated no bony lesion. No primary site of squamous cell carcinoma could be identified. An excisional biopsy of the swelling was performed, and the histologic diagnosis of pilomatrixoma was made.
CONCLUSION: The cytologic presentation of pilomatrixoma of the right submandibular region can masquerade as that of a malignant tumor, in this case mucoepidermoid carcinoma, squamous cell carcinoma or odontogenic tumor. This case delineates the cytomorphologic features of pilomatrixoma that may mimic carcinoma.
Data from 3691 dairy cows from 76 farms were used to investigate the risk factors associated with the area of hair loss over the lateral aspect of the hock and the correlation between the area of hair loss (as calculated using a hock map) and hock lesion scores determined using a pre-existing categorical scale. Six factors were associated with a greater area of hair loss, including cows with locomotion score 3, a cleanliness score (10/28 to 18/28), high daily milk yield (25.1-58.1 kg), poor body condition score (1-1.5), duration of winter housing (≥41 days) and some combinations of cubicle base and bedding materials. Compared with cows housed in cubicles with a concrete base and whole straw or rape straw bedding, cows housed in cubicles with concrete bases with sand or chopped straw bedding had smaller areas of hair loss and cows housed on a mattress base with whole straw or rape straw bedding had larger areas of hair loss. Area of hair loss, as measured on hock maps, was not significantly different between cows with score 1 (median 23.6 cm(2)) and score 2 (median 20.3 cm(2)) on the categorical scale for hock lesions. This suggests that the categorical scale was not reflecting the extent of hair loss and that hock maps are a good alternative for studying the dynamics of hock lesions over time.
A review of consecutive biopsies of adnexal tumours from 112 patients, received by the Department of Pathology, University of Malaya, over a 13-year period was undertaken. The age range of the patients was from 1 to 84 years, with a mean of 29.8 years. Thirty-three (32%) patients were under 20 years of age. There were 68 females with a male to female ratio of 1.0:1.5. In 105 cases (93.7%), the neoplasm was solitary. The tumour measured less than 2 cm in the largest dimension in 103 cases (92%). The common sites of occurrence were the head and neck region (59%) and extremities (25%). Neoplasms of hair follicle origin accounted for 63.4% (71 cases) of all lesions. Intra-tumour deposition of amyloid was noted in one of the 14 cases of trichoepithelioma.